1 00:00:05,200 --> 00:00:08,120 >> THIS IS WIN ARIAS WELCOMING 2 00:00:08,120 --> 00:00:10,080 YOU TO THE NINTH SESSION OF THE 3 00:00:10,080 --> 00:00:17,000 21ST YEAR OF THE NIH COURSE 4 00:00:17,000 --> 00:00:19,440 CALLED DEMYSTIFYING MEDICINE. 5 00:00:19,440 --> 00:00:22,240 THIS IS REALLY A COURSE IN 6 00:00:22,240 --> 00:00:23,160 BRIDGE-BUILDING. 7 00:00:23,160 --> 00:00:27,520 THE LOGO, WHICH AT LEAST FOR 8 00:00:27,520 --> 00:00:31,080 THOSE ON THIS SIDE OF THE 9 00:00:31,080 --> 00:00:33,880 ATLANTIC IS ALMOST CONSIDERED 10 00:00:33,880 --> 00:00:35,160 THE MOST FAMOUS BRIDGE IN THE 11 00:00:35,160 --> 00:00:36,760 WORLD IS MY GRANDFATHER'S 12 00:00:36,760 --> 00:00:37,640 PHOTOGRAPH OF THE CONSTRUCTION 13 00:00:37,640 --> 00:00:38,880 OF THE BROOKLYN BRIDGE. 14 00:00:38,880 --> 00:00:39,920 NORMALLY THE TWO INDIVIDUALS ON 15 00:00:39,920 --> 00:00:41,680 THE BRIDGE COME FROM DIFFERENT 16 00:00:41,680 --> 00:00:44,560 SIDES OF THE RIVER, THE EAST 17 00:00:44,560 --> 00:00:46,320 RIVER, AND ARE DISCUSSING ISSUES 18 00:00:46,320 --> 00:00:47,800 OF MAJOR IMPORTANCE, EACH 19 00:00:47,800 --> 00:00:51,280 REPRESENTING A DIFFERENT POINT 20 00:00:51,280 --> 00:00:53,560 OF VIEW AND A DIFFERENT 21 00:00:53,560 --> 00:00:54,000 EXPERTISE. 22 00:00:54,000 --> 00:00:55,080 IT'S AN EXERCISE IN 23 00:00:55,080 --> 00:00:57,480 COMMUNICATION. 24 00:00:57,480 --> 00:00:59,520 TODAY'S BRIDGE IS PROBABLY THE 25 00:00:59,520 --> 00:01:00,560 LONGEST -- WELL, IT'S CERTAINLY 26 00:01:00,560 --> 00:01:04,640 THE LONGEST AND MOST EXTENSIVE 27 00:01:04,640 --> 00:01:05,560 BRIDGE AND PROBABLY THE MOST 28 00:01:05,560 --> 00:01:06,920 IMPORTANT THAT WE COULD EVER 29 00:01:06,920 --> 00:01:07,600 CONSIDER, AND THAT'S THE ORIGIN 30 00:01:07,600 --> 00:01:12,120 OF LIFE. 31 00:01:12,120 --> 00:01:16,200 SO TODAY'S SPEAKERS WILL ADDRESS 32 00:01:16,200 --> 00:01:20,400 THIS. 33 00:01:20,400 --> 00:01:26,400 ONE IS AN EVOLUTIONARY 34 00:01:26,400 --> 00:01:28,480 BIOCHEMIST AND THE OTHER A CELL 35 00:01:28,480 --> 00:01:29,960 BIOLOGIST. 36 00:01:29,960 --> 00:01:30,200 I CAME UPON THIS QUOTATION FROM 37 00:01:30,200 --> 00:01:32,120 SYDNEY BRENNER. 38 00:01:32,120 --> 00:01:33,560 I THINK ONE OF THE THINGS ABOUT 39 00:01:33,560 --> 00:01:34,120 CREATIVITY IS NOT TO BE AFRAID 40 00:01:34,120 --> 00:01:39,040 OF SAYING THE WRONG THING. 41 00:01:39,040 --> 00:01:42,160 TO A CERTAIN EXTENT, THAT WILL 42 00:01:42,160 --> 00:01:43,000 INFLUENCE THE ENTIRE 43 00:01:43,000 --> 00:01:47,920 PRESENTATION TODAY. 44 00:01:47,920 --> 00:01:50,160 NOW THIS TOPIC REALLY BEGINS 45 00:01:50,160 --> 00:01:51,560 ABOUT 4 BILLION YEARS AGO, WHEN 46 00:01:51,560 --> 00:01:53,360 LIFE AROSE ON EARTH FROM 47 00:01:53,360 --> 00:01:55,080 NON-LIVING MATTER. 48 00:01:55,080 --> 00:01:58,600 BUT HOW, WHERE, AND WHY ARE 49 00:01:58,600 --> 00:02:01,600 MYSTERIES. 50 00:02:01,600 --> 00:02:03,400 THE EARLIEST LIFE FORMS WERE 51 00:02:03,400 --> 00:02:05,960 SIMPLE AND MICROSCOPIC, YET THEY 52 00:02:05,960 --> 00:02:08,880 HAD TWO PROPERTIES THAT SET THEM 53 00:02:08,880 --> 00:02:10,680 APART FROM OTHER ORGANIC 54 00:02:10,680 --> 00:02:15,200 CHEMICAL CHAINS IN THE 55 00:02:15,200 --> 00:02:16,720 ENVIRONMENT, AND THESE 56 00:02:16,720 --> 00:02:18,520 PROPERTIES COULD METABOLIZE AND 57 00:02:18,520 --> 00:02:19,400 THEY COULD REPLICATE. 58 00:02:19,400 --> 00:02:22,640 THIS IS THE ORIGIN OF LIFE, 59 00:02:22,640 --> 00:02:26,160 WHICH WILL BE DISCUSSED IN THE 60 00:02:26,160 --> 00:02:28,600 FIRST TALK BY DR. NICK LANE, 61 00:02:28,600 --> 00:02:32,160 WHO'S A PROFESSOR OF 62 00:02:32,160 --> 00:02:32,880 EVOLUTIONARY BIOCHEMISTRY IN THE 63 00:02:32,880 --> 00:02:44,400 DIVISION OF BIOSCIENCES AT THE 64 00:02:44,400 --> 00:02:47,320 UNIVERSITY COLLEGE LONDON. 65 00:02:47,320 --> 00:02:49,040 NICK'S RESEARCH IS DIRECTED 66 00:02:49,040 --> 00:02:51,560 TOWARD A BIOCHEMICAL EXPLANATION 67 00:02:51,560 --> 00:02:56,800 FOR THE ORIGIN OF LIFE AND THE 68 00:02:56,800 --> 00:02:58,120 EMERGENCE OF THE EUKARYOTIC 69 00:02:58,120 --> 00:02:58,520 CELL. 70 00:02:58,520 --> 00:03:00,320 THE GENERAL FOCUS OF HIS WORK 71 00:03:00,320 --> 00:03:09,440 HAS BEEN ON THE ROLE OF 72 00:03:09,440 --> 00:03:12,400 CHEMIOSMOSIS, THE GENERATION OF 73 00:03:12,400 --> 00:03:15,320 ATP BY WAY OF PROTON GRADIENTS. 74 00:03:15,320 --> 00:03:21,880 NICK IS AN OUTSTANDING TEACHER. 75 00:03:21,880 --> 00:03:23,520 AND IS AN AWARD-RIN WINNING 76 00:03:23,520 --> 00:03:27,360 AUTHOR -WINNING AUTHOR 77 00:03:27,360 --> 00:03:28,640 OF FOUR BOOKS, THE MOST RECENT 78 00:03:28,640 --> 00:03:32,280 PUBLISHED IN 2015 IS AN 79 00:03:32,280 --> 00:03:33,800 EXTRAORDINARY BOOK CALLED "THE 80 00:03:33,800 --> 00:03:36,800 VITAL QUESTION: WHY IS LIFE THE 81 00:03:36,800 --> 00:03:39,760 WAY IT IS?" 82 00:03:39,760 --> 00:03:42,160 A NEW BOOK WILL BE COMING OUT IN 83 00:03:42,160 --> 00:03:44,760 JULY, ENTITLED "TRANSFORMER: 84 00:03:44,760 --> 00:03:46,760 THE DEEP CHEMISTRY OF LIFE AND 85 00:03:46,760 --> 00:03:49,240 DEATH." 86 00:03:49,240 --> 00:03:54,160 AND SO NICK WILL BE THE FIRST 87 00:03:54,160 --> 00:03:55,400 SPEAKER, WHO WILL TALK ABOUT THE 88 00:03:55,400 --> 00:03:56,800 ORIGIN OF LIFE IN AN 89 00:03:56,800 --> 00:04:00,800 EVOLUTIONARY SENSE. 90 00:04:00,800 --> 00:04:02,840 NOW ABOUT 2 BILLION YEARS AGO, 91 00:04:02,840 --> 00:04:13,760 LIFE EXPLODED WITH A DAZZLING 92 00:04:13,760 --> 00:04:17,280 VARIETY -- WITH A VARIETY AND 93 00:04:17,280 --> 00:04:19,760 COMPLEXITY TO INCLUDE NOW 94 00:04:19,760 --> 00:04:21,120 MULTICELLULAR LIFE IN THE FORM 95 00:04:21,120 --> 00:04:29,160 OF THE EUKARYOTIC CELL. 96 00:04:29,160 --> 00:04:32,320 WELL, MANY THINGS HAPPENED 97 00:04:32,320 --> 00:04:32,960 BETWEEN ABIOGENESIS AND THE RISE 98 00:04:32,960 --> 00:04:36,080 OF THE FIRST EUKARYOTIC 99 00:04:36,080 --> 00:04:36,360 ANCESTOR. 100 00:04:36,360 --> 00:04:40,080 THIS WILL BE THE SUBJECT OF 101 00:04:40,080 --> 00:04:42,640 DR. JENNIFER 102 00:04:42,640 --> 00:04:44,800 LIPPINCOTT-SCHWARTZ'S 103 00:04:44,800 --> 00:04:47,200 PRESENTATION. 104 00:04:47,200 --> 00:04:49,160 JENNIFER, YOU KNOW, IS A SENIOR 105 00:04:49,160 --> 00:04:51,760 GROUP LEADER AT THE HOWARD 106 00:04:51,760 --> 00:04:54,880 HUGHES MEDICAL INSTITUTE AT 107 00:04:54,880 --> 00:04:56,440 JANELIA FARMS CAMPUS, AND 108 00:04:56,440 --> 00:05:01,120 FORMERLY, FROM 1993 TO 2015, SHE 109 00:05:01,120 --> 00:05:06,160 WAS CHIEF OF THE NIH NATIONAL 110 00:05:06,160 --> 00:05:07,280 INSTITUTE OF CHILD HEALTH AND 111 00:05:07,280 --> 00:05:08,760 DEVELOPMENT SECTION ON ORGANELLE 112 00:05:08,760 --> 00:05:14,400 BIOLOGY. 113 00:05:14,400 --> 00:05:15,960 JENNIFER'S APPROACH HAS BEEN 114 00:05:15,960 --> 00:05:17,240 TOTALLY DYNAMIC IN TERMS OF 115 00:05:17,240 --> 00:05:18,160 SCIENCE AND PERSONALITY. 116 00:05:18,160 --> 00:05:20,640 SHE DOES RESEARCH ON THE 117 00:05:20,640 --> 00:05:23,320 EUKARYOTIC CELL ORGANELLES AS 118 00:05:23,320 --> 00:05:26,080 DYNAMIC STRUCTURES, AND IN PART, 119 00:05:26,080 --> 00:05:29,160 THIS IS BECAUSE SHE HAS BEEN AN 120 00:05:29,160 --> 00:05:35,600 INNOVATOR IN LIVE, SUBSELL SUBCELLULAR 121 00:05:35,600 --> 00:05:39,680 AND SUPER-RESOLUTION MICROSCOPY, 122 00:05:39,680 --> 00:05:41,280 USING PHOTOACTIVATABLE 123 00:05:41,280 --> 00:05:42,000 ORGANELLE-SPECIFIC PROBES 124 00:05:42,000 --> 00:05:43,160 DEVELOPED AT NIH WITH THE LATE 125 00:05:43,160 --> 00:05:46,080 GEORGE PATTERSON. 126 00:05:46,080 --> 00:05:47,960 JENNIFER HAS RECEIVED NUMEROUS 127 00:05:47,960 --> 00:05:51,760 NATIONAL AND INTERNATIONAL 128 00:05:51,760 --> 00:05:52,400 AWARDS, INCLUDING ELECTION TO 129 00:05:52,400 --> 00:05:55,000 THE NATIONAL ACADEMY OF SCIENCE, 130 00:05:55,000 --> 00:05:56,360 THE NATIONAL ACADEMY OF 131 00:05:56,360 --> 00:05:58,000 MEDICINE, AND THE NATIONAL 132 00:05:58,000 --> 00:06:00,200 ACADEMY OF ARTS AND SCIENCES. 133 00:06:00,200 --> 00:06:04,440 AND SHE WILL BE DISCUSSING THE 134 00:06:04,440 --> 00:06:08,880 EMERGENCE OF THE EUKARYOTIC 135 00:06:08,880 --> 00:06:09,240 CELL. 136 00:06:09,240 --> 00:06:12,880 SO JOIN US IN A $4 BILLION 137 00:06:12,880 --> 00:06:14,960 JOURNEY TODAY, AS WE PROBE 138 00:06:14,960 --> 00:06:17,920 THEORIES AS TO HOW LIFE 139 00:06:17,920 --> 00:06:20,840 ORIGINATED, AND HOW IT BECAME 140 00:06:20,840 --> 00:06:23,000 MORE COMPLEX. 141 00:06:23,000 --> 00:06:24,200 SO PROFESSOR LANE, WOULD YOU 142 00:06:24,200 --> 00:06:32,720 PLEASE BEGIN. 143 00:06:32,720 --> 00:06:34,000 >> THANK YOU VERY MUCH FOR THE 144 00:06:34,000 --> 00:06:37,080 VERY KIND INTRODUCTION. 145 00:06:37,080 --> 00:06:38,480 AND FOR THE HUGE HONOR OF BEING 146 00:06:38,480 --> 00:06:38,960 HERE AT ALL. 147 00:06:38,960 --> 00:06:41,440 IT REALLY IS AN IMMENSE HONOR 148 00:06:41,440 --> 00:06:43,320 AND PLEASURE, AND I'M REALLY 149 00:06:43,320 --> 00:06:46,600 LOOKING FORWARD TO SPEAKING TO 150 00:06:46,600 --> 00:06:48,080 YOU. 151 00:06:48,080 --> 00:06:50,120 SO I'M GOING TO TALK ABOUT 152 00:06:50,120 --> 00:06:51,320 ENERGY AND MATTER AT THE ORIGIN 153 00:06:51,320 --> 00:06:51,560 OF LIFE. 154 00:06:51,560 --> 00:06:53,320 THESE ARE, I SHOULD SAY UP 155 00:06:53,320 --> 00:06:54,760 FRONT, IDEAS THAT I'VE BEEN 156 00:06:54,760 --> 00:06:56,240 CONJURING WITH FOR A LONG TIME, 157 00:06:56,240 --> 00:06:57,360 BUT LOTS OF PEOPLE WOULD NOT 158 00:06:57,360 --> 00:06:58,640 AGREE WITH ME AND YOU SHOULD BE 159 00:06:58,640 --> 00:07:05,000 AWARE OF THAT UP FRONT. 160 00:07:05,000 --> 00:07:06,840 SO I HAVE NO CONFLICTS OF 161 00:07:06,840 --> 00:07:07,120 INTEREST. 162 00:07:07,120 --> 00:07:08,480 THIS WAS FOR THE CME PROGRAM 163 00:07:08,480 --> 00:07:10,400 WHICH APPARENTLY IS NOT GOING 164 00:07:10,400 --> 00:07:12,280 AHEAD, SO YOUR LEARNING 165 00:07:12,280 --> 00:07:13,920 OBJECTIVE, YOU NO LONGER NEED TO 166 00:07:13,920 --> 00:07:14,840 UNDERSTAND THE ORIGIN OF LIFE, 167 00:07:14,840 --> 00:07:16,120 WHICH I'M SURE SOME OF YOU WILL 168 00:07:16,120 --> 00:07:19,600 BE PLEASED TO HEAR. 169 00:07:19,600 --> 00:07:25,960 BUT I LO DO MY WILL DO MY BEST TO MAKE IT 170 00:07:25,960 --> 00:07:27,040 INTELLIGIBLE ANYWAY. 171 00:07:27,040 --> 00:07:28,240 THE FIRST PROBLEM WE ALL HAVE 172 00:07:28,240 --> 00:07:29,320 WHEN WE TALK ABOUT THE ORIGIN OF 173 00:07:29,320 --> 00:07:32,120 LIFE IS TO WRESTLE WITH SOME 174 00:07:32,120 --> 00:07:33,360 DEFINITION OF WHAT IS LIFE 175 00:07:33,360 --> 00:07:34,400 ANYWAY, AND THERE ISN'T A GOOD 176 00:07:34,400 --> 00:07:35,120 DEFINITION OF IT. 177 00:07:35,120 --> 00:07:36,720 THERE ARE ACTUALLY SCORES OF BAD 178 00:07:36,720 --> 00:07:38,520 DEFINITIONS OF IT, AND I THINK 179 00:07:38,520 --> 00:07:43,760 PART OF THE PROBLEM, LIFE IS NOT 180 00:07:43,760 --> 00:07:45,800 A NOUN, IT'S A VERB, IT'S A 181 00:07:45,800 --> 00:07:47,760 PROCESS OVER TIME, IT'S AN 182 00:07:47,760 --> 00:07:49,200 ACTIVITY, AND REALLY A BETTER 183 00:07:49,200 --> 00:07:50,480 QUESTION IS WHAT IS LIVING. 184 00:07:50,480 --> 00:07:52,200 A LOT OF PEOPLE, I HOPE, MIGHT 185 00:07:52,200 --> 00:07:58,880 HAVE READ THIS FAMOUS BOOK BY 186 00:07:58,880 --> 00:08:02,520 ERWIN SCHRODINGER CALLED WHAT IS 187 00:08:02,520 --> 00:08:03,960 LIFE, A BEAUTIFUL BOOK, DATING 188 00:08:03,960 --> 00:08:05,920 BACK TO BEFORE THE TIME ANYBODY 189 00:08:05,920 --> 00:08:07,400 REALIZED THAT GENES WERE MADE OF 190 00:08:07,400 --> 00:08:09,120 DNA. 191 00:08:09,120 --> 00:08:11,440 MOST CERTAINLY IT WAS NOT 192 00:08:11,440 --> 00:08:12,720 ESTABLISHED IN THE FIELD IN THE 193 00:08:12,720 --> 00:08:19,120 EARLY 1940s. 194 00:08:19,120 --> 00:08:21,760 AND HE TALKED IN -- THIS IS 195 00:08:21,760 --> 00:08:23,360 APPARENTLY THE FIRST USE OF THE 196 00:08:23,360 --> 00:08:26,320 WORD CODE SCRIPT IN BIOLOGY. 197 00:08:26,320 --> 00:08:27,920 DURING THE SECOND WORLD WAR, AT 198 00:08:27,920 --> 00:08:32,120 A TIME WHEN CRYPTOGRAPHY WAS 199 00:08:32,120 --> 00:08:33,680 VERY MUCH IN THE AIR. 200 00:08:33,680 --> 00:08:36,440 HE ALSO TALKED ABOUT ENTROPY, 201 00:08:36,440 --> 00:08:39,720 LIFE FEEDING ON NEGATIVE 202 00:08:39,720 --> 00:08:40,920 ENTROPY, AND HERE QUITE 203 00:08:40,920 --> 00:08:42,840 ANTIQUATED, HE SAYS LIFE 204 00:08:42,840 --> 00:08:43,760 MAINTAINS ITSELF AS A FAIRLY 205 00:08:43,760 --> 00:08:47,320 HIGH LEVEL OF ORDERLINESS 206 00:08:47,320 --> 00:08:53,120 THROUGH CONTINUALLY SUCKING 207 00:08:53,120 --> 00:08:53,680 ORDERLINESS FROM ITS 208 00:08:53,680 --> 00:08:55,080 ENVIRONMENT. 209 00:08:55,080 --> 00:08:57,080 I DON'T KNOW WHAT HE HAD IN MIND 210 00:08:57,080 --> 00:08:57,880 WHEN HE SAID THAT. 211 00:08:57,880 --> 00:08:59,760 HE SAID IF I WAS CATERING FOR 212 00:08:59,760 --> 00:09:01,160 PHYSICISTS ALONE, I SHOULD HAVE 213 00:09:01,160 --> 00:09:02,240 LET THE DISCUSSION TURN TO FREE 214 00:09:02,240 --> 00:09:04,120 ENERGY INSTEAD. 215 00:09:04,120 --> 00:09:05,720 SO JUST TO MAKE SURE WE'RE ALL 216 00:09:05,720 --> 00:09:07,360 ON THE SAME PAGE, HE DIDN'T TALK 217 00:09:07,360 --> 00:09:08,480 ABOUT FREE ENERGY BECAUSE HE 218 00:09:08,480 --> 00:09:09,360 THOUGHT IT WAS A MORE COMPLEX 219 00:09:09,360 --> 00:09:10,320 TERM THAN ENTROPY. 220 00:09:10,320 --> 00:09:11,680 I THINK MOST BIOLOGISTS WOULD 221 00:09:11,680 --> 00:09:13,880 PROBABLY SEE IT THE OTHER WAY 222 00:09:13,880 --> 00:09:15,360 AROUND, FREE ENERGY SIMPLY AS I 223 00:09:15,360 --> 00:09:19,760 SEE IT, THE ENERGY AVAILABLE TO 224 00:09:19,760 --> 00:09:22,720 POWER WORK, MUSCLE CONTRACTION, 225 00:09:22,720 --> 00:09:23,640 CONFORMATIONAL CHANGES IN PLEK 226 00:09:23,640 --> 00:09:27,680 NAR 227 00:09:27,680 --> 00:09:32,920 MOLECULAR MACHINES, SO ON, 228 00:09:32,920 --> 00:09:34,360 GENERATING ATP, I'M SURE I'M 229 00:09:34,360 --> 00:09:35,920 TALKING THE LANGUAGE OF 230 00:09:35,920 --> 00:09:37,800 EVERYBODY ON THIS CALL. 231 00:09:37,800 --> 00:09:39,720 AND OF COURSE WE TURN OVER 232 00:09:39,720 --> 00:09:40,520 SOMETHING APPROXIMATING TO OUR 233 00:09:40,520 --> 00:09:42,880 OWN BODY WEIGHT IN ATP EVERY 234 00:09:42,880 --> 00:09:43,640 DAY. 235 00:09:43,640 --> 00:09:45,080 IT'S VERY DIFFICULT TO CONVEY 236 00:09:45,080 --> 00:09:47,760 JUST HOW MUCH ENERGY IT COSTS 237 00:09:47,760 --> 00:09:52,200 JUST TO STAY ALIVE. 238 00:09:52,200 --> 00:09:53,080 AND IF YOU START TO THINK ABOUT 239 00:09:53,080 --> 00:09:54,640 THE ORIGIN OF LIFE, THEN WE HAVE 240 00:09:54,640 --> 00:09:56,240 TO THINK ABOUT UNIVERSALS ACROSS 241 00:09:56,240 --> 00:09:57,400 LIFE, AND WE ALL KNOW ABOUT DNA 242 00:09:57,400 --> 00:10:00,960 AND THE UNIVERSAL GENETIC CODE, 243 00:10:00,960 --> 00:10:02,400 AND IT'S PERHAPS LESS OBVIOUS 244 00:10:02,400 --> 00:10:07,400 THAT THERE ISS IS ALSO A UNIVERSAL 245 00:10:07,400 --> 00:10:09,320 FORM OF FREE ENERGY CONSERVATION 246 00:10:09,320 --> 00:10:10,760 ACROSS ALL LIVING THINGS. 247 00:10:10,760 --> 00:10:12,920 IT GOES BEYOND ATP, IT'S ALSO 248 00:10:12,920 --> 00:10:14,600 THE MECHANISM IN WHICH OUR 249 00:10:14,600 --> 00:10:15,760 MITOCHONDRIA AND CELLS IN 250 00:10:15,760 --> 00:10:18,520 GENERAL, BACTERIA AND SO ON, ARE 251 00:10:18,520 --> 00:10:20,000 POWERING THE SYNTHESIS OF ATP 252 00:10:20,000 --> 00:10:22,320 THROUGH THE USE OF ION GRADE 253 00:10:22,320 --> 00:10:25,240 YANTS AND ESPECIALLY PROTON 254 00:10:25,240 --> 00:10:26,880 GRADIENTS ACROSS MEMBRANES. 255 00:10:26,880 --> 00:10:29,000 THAT'S REALLY A VERY SIMPLE 256 00:10:29,000 --> 00:10:30,080 DIFFERENCE IN THE CONCENTRATION 257 00:10:30,080 --> 00:10:31,160 AND THEREFORE THE CHARGE BETWEEN 258 00:10:31,160 --> 00:10:33,080 ONE SIDE OF THE MEMBRANE AND THE 259 00:10:33,080 --> 00:10:34,160 OTHER SIDE OF THE MEMBRANE. 260 00:10:34,160 --> 00:10:37,320 THE USE OF THESE GRADE YANTS IS 261 00:10:37,320 --> 00:10:39,200 AS UNIVERSAL AS THE GENETIC CODE 262 00:10:39,200 --> 00:10:39,920 ITSELF ACROSS ALL OF LIFEMENT 263 00:10:39,920 --> 00:10:41,480 BUT THE MACHINERY THAT'S 264 00:10:41,480 --> 00:10:43,000 POWERING THIS IS EXTRAORDINARILY 265 00:10:43,000 --> 00:10:43,760 COMPLEX AND I'M JUST GOING TO 266 00:10:43,760 --> 00:10:46,920 GIVE YOU A SNAPSHOT. 267 00:10:46,920 --> 00:10:49,040 I'M SURE MANY OF YOU ARE MORE 268 00:10:49,040 --> 00:10:50,040 FAMILIAR WITH THESE KIND OF 269 00:10:50,040 --> 00:10:51,080 MOLECULAR MACHINES THAN I AM 270 00:10:51,080 --> 00:10:52,840 BECAUSE I DON'T SPECIFICALLY 271 00:10:52,840 --> 00:10:56,720 WORK ON THESE, BUT THEY ARE 272 00:10:56,720 --> 00:11:01,080 ABSOLUTELY GLORIOUS, MARVELOUS, 273 00:11:01,080 --> 00:11:02,120 AND PROMOTE FROM THE POINT OF 274 00:11:02,120 --> 00:11:04,960 VIEW OF A BIOCHEMIST WONDERING 275 00:11:04,960 --> 00:11:06,320 ABOUT HOW SUCH MACHINERY AROSE 276 00:11:06,320 --> 00:11:07,720 AT THE ORIGIN OF LIFE DUMB 277 00:11:07,720 --> 00:11:08,560 FOUNDING, REALLY. 278 00:11:08,560 --> 00:11:09,800 THEY'RE PLAINLY A PRODUCT OF 279 00:11:09,800 --> 00:11:11,960 GENES AND NATURAL SELECTION, AND 280 00:11:11,960 --> 00:11:13,680 SO THEY SEEM TO HAVE NOTHING 281 00:11:13,680 --> 00:11:16,080 WHATSOEVER TO DO WITH PREBIOTIC 282 00:11:16,080 --> 00:11:16,520 CHEMISTRY. 283 00:11:16,520 --> 00:11:18,280 THESE ARE THE PINNACLES OF 284 00:11:18,280 --> 00:11:19,760 EVOLUTION, NOT THE BEGINNINGS OF 285 00:11:19,760 --> 00:11:20,120 EVOLUTION. 286 00:11:20,120 --> 00:11:21,200 FOR THAT REASON, MOST PEOPLE 287 00:11:21,200 --> 00:11:22,880 HAVE PUT IT ASIDE AND DON'T 288 00:11:22,880 --> 00:11:26,880 WORRY ABOUT IT AND TEND TO 289 00:11:26,880 --> 00:11:29,360 DISMISS MEMBRANE -- SOMETHING 290 00:11:29,360 --> 00:11:31,080 THAT AROSE MUCH LATER IN 291 00:11:31,080 --> 00:11:32,520 EVOLUTION AND WE HAVE TO LOOK AT 292 00:11:32,520 --> 00:11:33,320 SIMPLE THINGS AT THE ORIGIN OF 293 00:11:33,320 --> 00:11:33,720 LIFE. 294 00:11:33,720 --> 00:11:34,720 AND THERE'S PLENTY OF IDEAS OUT 295 00:11:34,720 --> 00:11:37,120 THERE. 296 00:11:37,120 --> 00:11:43,240 REACTIVE GASES, CYANIDE OR 297 00:11:43,240 --> 00:11:45,720 CYANOD ACETYLENE, SO ON, 298 00:11:45,720 --> 00:11:48,240 ENERGIZING LIGHT, UV RADIATION, 299 00:11:48,240 --> 00:11:50,560 LIGHTNING, ALL KINDS OF DYNAMIC 300 00:11:50,560 --> 00:11:54,120 ENVIRONMENTS, WET/DRY CYCLES, 301 00:11:54,120 --> 00:11:56,640 THIS IS THE PREDOMINANT AREA OF 302 00:11:56,640 --> 00:11:57,680 THIS FIELD RIGHT NOW AND THIS 303 00:11:57,680 --> 00:11:59,320 HAS BEEN GOING FOR 50 OR 60 304 00:11:59,320 --> 00:12:02,520 YEARS GOING BACK, REALLY, TO THE 305 00:12:02,520 --> 00:12:03,280 EXPERIMENT WITH BOLTS OF 306 00:12:03,280 --> 00:12:05,720 LIGHTNING TO TRY AND EFFECTIVELY 307 00:12:05,720 --> 00:12:07,640 ENERGIZE THE GASES IN THOSE 308 00:12:07,640 --> 00:12:08,400 EARLY ATMOSPHERES. 309 00:12:08,400 --> 00:12:09,960 AND IT'S WORKED EXTREMELY WELL 310 00:12:09,960 --> 00:12:11,600 AND THE CHEMISTS THINK THEY'VE 311 00:12:11,600 --> 00:12:13,840 SOLVED THE PROBLEM, BUT FROM A 312 00:12:13,840 --> 00:12:16,720 BIOLOGIST'S POINT OF VIEW, IT'S 313 00:12:16,720 --> 00:12:18,200 TO MY MIND FRANKENSTEIN 314 00:12:18,200 --> 00:12:18,480 CHEMISTRY. 315 00:12:18,480 --> 00:12:19,680 IT LOOKS NOTHING LIKE THE 316 00:12:19,680 --> 00:12:20,520 CHEMISTRY OF LIFE AS I 317 00:12:20,520 --> 00:12:23,320 UNDERSTAND IT. 318 00:12:23,320 --> 00:12:24,920 SO I SUPPOSE AT THE VERY LEAST, 319 00:12:24,920 --> 00:12:26,400 EVEN IF THIS CHEMISTRY IS, IN 320 00:12:26,400 --> 00:12:27,720 FACT, ALL THE RIGHT CHEMISTRY, 321 00:12:27,720 --> 00:12:29,920 AND LIFE REALLY DID START IN 322 00:12:29,920 --> 00:12:33,680 THIS WAY, WE STILL HAVE A GAP. 323 00:12:33,680 --> 00:12:35,080 WE STILL HAVE TO EXPLAIN, OKAY, 324 00:12:35,080 --> 00:12:37,000 SO WE'VE GOT ALL OF THESE 325 00:12:37,000 --> 00:12:38,040 CHEMICALS, HOW DID METABOLISM 326 00:12:38,040 --> 00:12:41,720 THEN START, HOW DID GENES INVENT 327 00:12:41,720 --> 00:12:42,920 METABOLISM, AND METABOLISM AS WE 328 00:12:42,920 --> 00:12:44,120 KNOW IT IN CELLS TODAY, BECAUSE 329 00:12:44,120 --> 00:12:46,520 THIS IS NOTHING LIKE THE 330 00:12:46,520 --> 00:12:48,280 METABOLISM OF CELLS AS WE KNOW 331 00:12:48,280 --> 00:12:48,480 THEM. 332 00:12:48,480 --> 00:12:50,320 SO FROM A BIOLOGIST'S POINT OF 333 00:12:50,320 --> 00:12:51,520 VIEW, I AM VERY UNCOMFORTABLE 334 00:12:51,520 --> 00:12:54,240 WITH THOSE ANSWERS. 335 00:12:54,240 --> 00:12:58,120 AND I TURN TO PEOPLE LIKE 336 00:12:58,120 --> 00:12:59,560 CHRISTIAN DE DUVE WHO TRIED TO 337 00:12:59,560 --> 00:13:01,400 USE BIOLOGY RATHER THAN 338 00:13:01,400 --> 00:13:02,280 CHEMISTRY AS A GUIDE TO LIFE'S 339 00:13:02,280 --> 00:13:02,720 ORIGINS. 340 00:13:02,720 --> 00:13:06,160 THERE'S A LOVELY QUOTE FROM DE 341 00:13:06,160 --> 00:13:09,240 DUVE HERE, HE SAYS HOW DID 342 00:13:09,240 --> 00:13:10,520 PROTOMETABOLISM, BY WHICH HE 343 00:13:10,520 --> 00:13:12,320 MEANT GEOLOGICAL CHEMISTRY, THE 344 00:13:12,320 --> 00:13:15,720 GEOCHEMISTRY HAPPENING IN SOME 345 00:13:15,720 --> 00:13:16,880 ENVIRONMENTAL CONTEXT, HOW DID 346 00:13:16,880 --> 00:13:20,800 THAT KIND OF DYNAMIC CHEMISTRY, 347 00:13:20,800 --> 00:13:22,080 PROTO METABOLISM, COME TO BE 348 00:13:22,080 --> 00:13:23,320 REPLACED BY METABOLISM AS WE 349 00:13:23,320 --> 00:13:24,160 KNOW IT? 350 00:13:24,160 --> 00:13:25,800 HE SAYS THE OBVIOUS ANSWER IS 351 00:13:25,800 --> 00:13:28,920 THAT THE APPEARANCE OF 352 00:13:28,920 --> 00:13:30,960 CATALYSTS, WHETHER RIBOZYMES, 353 00:13:30,960 --> 00:13:32,440 PROTEIN ENZYMES OR BOTH, WAS 354 00:13:32,440 --> 00:13:33,320 RESPONSIBLE FOR THE TRANSITION. 355 00:13:33,320 --> 00:13:34,960 WE HAVE TO ASK HOW CATALYSTS 356 00:13:34,960 --> 00:13:36,320 WITH THE APPROPRIATE PROPERTIES 357 00:13:36,320 --> 00:13:37,120 CAME TO APPEAR. 358 00:13:37,120 --> 00:13:38,640 WHY DO THEY CATALYZE THE RIGHT 359 00:13:38,640 --> 00:13:39,120 REACTIONS? 360 00:13:39,120 --> 00:13:41,080 HE SAYS THE ONLY SCIENTIFICALLY 361 00:13:41,080 --> 00:13:43,720 PLAUSIBLE EXPLANATION IS THE 362 00:13:43,720 --> 00:13:44,560 CATALYSTS AROSE THROUGH 363 00:13:44,560 --> 00:13:44,880 SELECTION. 364 00:13:44,880 --> 00:13:46,240 THEN IN THE KILLER LINE, ENZYMES 365 00:13:46,240 --> 00:13:48,120 ARE SELECTED ONLY IF THEY FIT 366 00:13:48,120 --> 00:13:49,320 INTO PROTO METABOLISM. 367 00:13:49,320 --> 00:13:51,320 NOW THIS IS HARDLY AN EAR 368 00:13:51,320 --> 00:13:53,520 REFUSABLE ARGUMENT BUT IT 369 00:13:53,520 --> 00:13:55,240 CERTAINLY A POWERFUL CASE, HE'S 370 00:13:55,240 --> 00:13:56,880 BASICALLY ARGUING THAT 371 00:13:56,880 --> 00:13:58,920 METABOLISM AMPLIFIED THE 372 00:13:58,920 --> 00:13:59,720 GEOCHEMICAL PATHWAYS THAT 373 00:13:59,720 --> 00:14:02,400 PRECEDED IT. 374 00:14:02,400 --> 00:14:03,520 AND THAT MAKES A LOT OF SENSE TO 375 00:14:03,520 --> 00:14:03,880 ME. 376 00:14:03,880 --> 00:14:05,520 THE ONLY PROBLEM IS, THEY NEVER 377 00:14:05,520 --> 00:14:06,160 REALLY SEEM TO WORK. 378 00:14:06,160 --> 00:14:07,280 PEOPLE HAVE TRIED THESE 379 00:14:07,280 --> 00:14:08,920 EXPERIMENTS AND UNTIL RECENTLY, 380 00:14:08,920 --> 00:14:10,200 THEY HAVEN'T WORKED WELL, BUT 381 00:14:10,200 --> 00:14:11,240 RECENTLY, THINGS HAVE REALLY 382 00:14:11,240 --> 00:14:12,120 CHANGED AND I'M GOING TO TELL 383 00:14:12,120 --> 00:14:16,720 YOU MORE ABOUT THAT IN THIS 384 00:14:16,720 --> 00:14:16,920 TALK. 385 00:14:16,920 --> 00:14:19,000 BUT WHAT KIND OF CHEMISTRY DO WE 386 00:14:19,000 --> 00:14:20,200 ACTUALLY NEED TO TALK ABOUT? 387 00:14:20,200 --> 00:14:24,920 TO DO THAT, WE NEED TO GET BACK 388 00:14:24,920 --> 00:14:26,560 TO THE ROOTS OF THE TREE OF LIFE 389 00:14:26,560 --> 00:14:27,800 AND ONE OF THE MOST BRILLIANT 390 00:14:27,800 --> 00:14:29,680 SCIENTISTS WORKING IN THIS FIELD 391 00:14:29,680 --> 00:14:31,760 FOR MANY YEARS NOW, OVER SEVERAL 392 00:14:31,760 --> 00:14:32,920 DECADES, IS BILL MARTIN. 393 00:14:32,920 --> 00:14:34,840 NOW, HE HAS SOME VERY RADICAL 394 00:14:34,840 --> 00:14:35,200 IDEAS. 395 00:14:35,200 --> 00:14:38,280 A LOT OF PEOPLE FIND HIS IDEAS 396 00:14:38,280 --> 00:14:40,000 VERY UNCOMFORTABLE. 397 00:14:40,000 --> 00:14:42,360 I CERTAINLY DID MYSELF, BUT THE 398 00:14:42,360 --> 00:14:44,720 LONGER I'VE LIVED WITH THEM, THE 399 00:14:44,720 --> 00:14:46,240 MORE I THINK HE'S BANG-ON. 400 00:14:46,240 --> 00:14:48,680 NOW THIS TREE I'M SHOWING YOU 401 00:14:48,680 --> 00:14:50,200 HERE IS FROM ONE OF BILL'S 402 00:14:50,200 --> 00:14:51,280 PAPERS FROM MORE THAN 20 YEARS 403 00:14:51,280 --> 00:14:51,920 AGO NOW. 404 00:14:51,920 --> 00:14:53,160 IT'S BASICALLY A CONCEPTUAL 405 00:14:53,160 --> 00:14:53,440 TREE. 406 00:14:53,440 --> 00:14:55,040 WHAT HE'S SHOWING IS THE 407 00:14:55,040 --> 00:14:56,240 EUKARYOTES UP HERE, WHICH 408 00:14:56,240 --> 00:14:57,240 JENNIFER WILL TALK ABOUT IN A 409 00:14:57,240 --> 00:14:58,760 WHILE, AND THE YOU'RE CARE YOTS, 410 00:14:58,760 --> 00:15:04,920 YOU THEY'RE GIVING 411 00:15:04,920 --> 00:15:06,520 RISE TO -- DEEPER DOWN IN THE 412 00:15:06,520 --> 00:15:09,560 TREE BETWEEN BACTERIUM OF SOME 413 00:15:09,560 --> 00:15:12,560 SORT THAT BECAME THE 414 00:15:12,560 --> 00:15:14,160 MITOCHONDRIA, THEN A HOST CELL. 415 00:15:14,160 --> 00:15:16,760 SO THE POINT FOR MY TALK IS THAT 416 00:15:16,760 --> 00:15:18,440 EUKARYOTES ARE A DERIVED DOMAIN. 417 00:15:18,440 --> 00:15:19,480 THEY DON'T SPEAK DIRECTLY TO 418 00:15:19,480 --> 00:15:20,480 WHAT WAS HAPPENING RIGHT DOWN AT 419 00:15:20,480 --> 00:15:22,040 THE BASE OF THE TREE DOWN HERE. 420 00:15:22,040 --> 00:15:24,080 NOW AGAIN, NOT EVERYBODY AGREES 421 00:15:24,080 --> 00:15:25,160 WITH THAT STATEMENT, BUT 422 00:15:25,160 --> 00:15:26,280 PROBABLY THAT WOULD BE A 423 00:15:26,280 --> 00:15:28,920 CONSENSUS IN THIS FIELD NOW. 424 00:15:28,920 --> 00:15:31,360 SO LUCA IS THE LAST UNIVERSAL 425 00:15:31,360 --> 00:15:32,720 COMMON ANCESTOR OF ALL OF LIFE, 426 00:15:32,720 --> 00:15:34,920 AND IT'S THE ANCESTOR OF THE 427 00:15:34,920 --> 00:15:38,480 BACTERIA AND THE ARCHAEA, WHICH 428 00:15:38,480 --> 00:15:39,720 LOOKED A LOT ALIKE IN TERMS OF 429 00:15:39,720 --> 00:15:41,440 THEIR GROSS OVERALL MORPHOLOGY. 430 00:15:41,440 --> 00:15:45,640 AND BILL HAS LUCA DOWN HERE WITH 431 00:15:45,640 --> 00:15:46,760 TWO SEPARATE EMERGENCES FROM 432 00:15:46,760 --> 00:15:49,120 THIS VENT WHICH IS ITSELF A VERY 433 00:15:49,120 --> 00:15:49,680 RADICAL IDEA. 434 00:15:49,680 --> 00:15:52,440 HE'S NOT SAYING THEY ORIGINATED 435 00:15:52,440 --> 00:15:53,000 INDEPENDENTLY, HE SAID THEY 436 00:15:53,000 --> 00:15:55,680 SHARED A COMMON ANCESTOR THAT 437 00:15:55,680 --> 00:15:57,760 LIVED IN A ROCKY HYDROTHERMAL 438 00:15:57,760 --> 00:15:58,120 SYSTEM. 439 00:15:58,120 --> 00:15:59,320 WHY WOULD HE SAY SUCH A THING? 440 00:15:59,320 --> 00:16:03,120 HE OOO ESSENTIALLY BECAUSE IT'S PLAIN 441 00:16:03,120 --> 00:16:04,960 THAT LIFE SHARES A COMMON 442 00:16:04,960 --> 00:16:05,720 ANCESTOR, AND THAT'S BECAUSE 443 00:16:05,720 --> 00:16:07,760 LIFE SHARES THE UNIVERSAL 444 00:16:07,760 --> 00:16:09,440 GENETIC CODE, THE STRUCTURE OF 445 00:16:09,440 --> 00:16:11,520 THE PROTEIN FACTORIES, THE 446 00:16:11,520 --> 00:16:17,520 PROTEIN-MAKING FACTORIES OF THE 447 00:16:17,520 --> 00:16:19,720 RIBOSOMES, QUITE A LOT OF 448 00:16:19,720 --> 00:16:20,760 INTERMEDIARY METABOLISM LIKE THE 449 00:16:20,760 --> 00:16:22,560 KREBS CYCLE. 450 00:16:22,560 --> 00:16:27,000 MOST IMPORTANTLY FROM THIS LEBLG 451 00:16:27,000 --> 00:16:28,920 LECTURE, MEMBRANE BIOINER JE 452 00:16:28,920 --> 00:16:29,120 TICS. 453 00:16:29,120 --> 00:16:31,120 WHAT'S SHOCKING, THE CELL 454 00:16:31,120 --> 00:16:32,640 MEMBRANE IS DIFFERENT IN ITS 455 00:16:32,640 --> 00:16:34,360 CHEMISTRY, VERY DIFFERENT IN ITS 456 00:16:34,360 --> 00:16:38,200 CHEMISTRY AND BACTERIA AND 457 00:16:38,200 --> 00:16:39,800 ARCHAEA ALONG WITH ALL THE LIPID 458 00:16:39,800 --> 00:16:42,040 SYNTHESIS REQUIRED TO GENERATE 459 00:16:42,040 --> 00:16:42,680 THESE MEMBRANES ALONG WITH THE 460 00:16:42,680 --> 00:16:43,040 CELL WALL. 461 00:16:43,040 --> 00:16:44,320 SO BASICALLY THE BARRIER BETWEEN 462 00:16:44,320 --> 00:16:46,320 THE INSIDE OF THE CELL AND THE 463 00:16:46,320 --> 00:16:48,240 OUTSIDE OF THE CELL ARE NOT 464 00:16:48,240 --> 00:16:50,720 HOMOLOGOUS, THEY HAVE APPEARED 465 00:16:50,720 --> 00:16:51,520 TO EMERGE INDEPENDENTLY AND THAT 466 00:16:51,520 --> 00:16:52,880 LEAVES YOU CONJURING WITH WHAT 467 00:16:52,880 --> 00:16:55,720 ON EARTH DID THE COMMON ANCESTOR 468 00:16:55,720 --> 00:16:56,280 HAVE THEN? 469 00:16:56,280 --> 00:16:57,720 ALMOST CERTAINLY HAD A CELL 470 00:16:57,720 --> 00:16:59,560 MEMBRANE, I DON'T KNOW IF IT HAD 471 00:16:59,560 --> 00:17:01,320 A CELL WALL OR NOT BUT IT WAS 472 00:17:01,320 --> 00:17:06,720 NOT LIKE A MODERN BACTERIA OR 473 00:17:06,720 --> 00:17:09,360 MODERN -- MEMBRANE. 474 00:17:09,360 --> 00:17:11,120 EVEN DNA REPLICATION, THE GENES 475 00:17:11,120 --> 00:17:14,520 INVOLVED ARE NOT CONSERVED IN 476 00:17:14,520 --> 00:17:16,920 BACTERIA -- ONLY ONE OR TWO OF 477 00:17:16,920 --> 00:17:17,520 THEM. 478 00:17:17,520 --> 00:17:18,920 VARIOUS PROTEINS OR GENES THAT 479 00:17:18,920 --> 00:17:22,920 CAN MOVE AROUND INCLUDING THOSE 480 00:17:22,920 --> 00:17:23,920 ENCODING THE RESPIRATORY CHAIN 481 00:17:23,920 --> 00:17:24,920 IN RESPIRATION DON'T REALLY 482 00:17:24,920 --> 00:17:27,760 APPEAR TO BE DEEPLY CONSERVED. 483 00:17:27,760 --> 00:17:29,720 SO THIS LEAVES YOU WONDERING, 484 00:17:29,720 --> 00:17:32,520 WHAT ON EARTH WAS LUCA, THIS 485 00:17:32,520 --> 00:17:33,840 LAST UNIVERSAL COMMON ANCESTOR, 486 00:17:33,840 --> 00:17:36,000 WHAT KIND OF A CELL WAS IT? 487 00:17:36,000 --> 00:17:37,640 IT'S QUITE A PARADOX. 488 00:17:37,640 --> 00:17:40,800 THE PARADOX AS I SEE IT IS, 489 00:17:40,800 --> 00:17:48,520 MEMBRANE BIOINER JE TICS ENERGETICS -- TH E 490 00:17:48,520 --> 00:17:49,720 PARADOX COULD BE RESOLVED IF 491 00:17:49,720 --> 00:17:51,320 LIFE ORIGINATED IN AN 492 00:17:51,320 --> 00:17:52,920 ENVIRONMENT WHERE THERE WERE 493 00:17:52,920 --> 00:17:56,320 GEOLOGICAL PROTON GRADIENTS WITH 494 00:17:56,320 --> 00:17:57,760 BARRIERS NOT NECESSARILY LIKE 495 00:17:57,760 --> 00:17:59,160 MODERN MEMBRANES. 496 00:17:59,160 --> 00:18:00,280 IS THERE SUCH A PLACE? 497 00:18:00,280 --> 00:18:06,000 YES, THEY WERE DISCOVERED YEARS 498 00:18:06,000 --> 00:18:13,040 AGO BY DEBORAH KELLEY, 499 00:18:13,040 --> 00:18:16,320 DISCOVERED ABOUT 15 MILES AWAY 500 00:18:16,320 --> 00:18:17,520 FROM THERE THIS COMPLETELY 501 00:18:17,520 --> 00:18:19,120 DIFFERENT TYPE OF HYDROTHERMAL 502 00:18:19,120 --> 00:18:20,120 SYSTEM. 503 00:18:20,120 --> 00:18:22,360 THEY'RE NOW KNOWN AS ALKALINE 504 00:18:22,360 --> 00:18:23,400 HYDROTHERMAL VENTS, LOST CITY 505 00:18:23,400 --> 00:18:25,640 WAS THE ONE SHE DISCOVERED AND 506 00:18:25,640 --> 00:18:27,720 IT'S NOT LIKE THE BLACK SMOKERS, 507 00:18:27,720 --> 00:18:30,720 SO SHE'S HOLDING A LUMP OF A 508 00:18:30,720 --> 00:18:32,040 BLACK SMOKER, YOU CAN SEE IT'S A 509 00:18:32,040 --> 00:18:34,120 CHIMNEY, THE BLACK SMOKER WOBBLE 510 00:18:34,120 --> 00:18:40,200 CH OUT WOULD 511 00:18:40,200 --> 00:18:42,760 BELCH OUT. 512 00:18:42,760 --> 00:18:44,200 THE HYDROTHERMAL FLUIDS WILL 513 00:18:44,200 --> 00:18:45,800 PERCOLATE THROUGH THE SPONG, 514 00:18:45,800 --> 00:18:47,480 THEY DON'T KIND OF BELCH OUT 515 00:18:47,480 --> 00:18:49,440 THROUGH THE TOP. 516 00:18:49,440 --> 00:18:51,720 INSTEAD OF BEING FORMED BY 517 00:18:51,720 --> 00:18:52,920 DIRECT INTERACTIONS BETWEEN 518 00:18:52,920 --> 00:18:59,000 OCEAN WATER AND MAGMA CHAMBERS 519 00:18:59,000 --> 00:19:03,760 FROM THE THOUSANDS OF DEGREES, 520 00:19:03,760 --> 00:19:05,040 THE MAGMA, THIS IS WATER 521 00:19:05,040 --> 00:19:05,680 PERCOLATING DOWN. 522 00:19:05,680 --> 00:19:13,280 LET ME PUT MY POINTER ON IT. 523 00:19:13,280 --> 00:19:14,800 SO WATER WILL PERCOLATE DOWN 524 00:19:14,800 --> 00:19:21,880 INTO THE SEA FLOOR 5 OR 525 00:19:21,880 --> 00:19:25,320 6 KILOMETERS DEPTH, OXIDIZING 526 00:19:25,320 --> 00:19:28,840 THE ION FROM FERROUS, AND THAT 527 00:19:28,840 --> 00:19:30,720 PRODUCES WARM IN GEOLOGICAL 528 00:19:30,720 --> 00:19:33,720 TERMS, 50 TO 100 DEGREES, FOR 529 00:19:33,720 --> 00:19:36,360 EXAMPLE, STRONGLY ALKALINE, PH10 530 00:19:36,360 --> 00:19:38,760 OR 11, AND SATURATED IN HYDROGEN 531 00:19:38,760 --> 00:19:40,760 GAS, BUBBLING IN HYDROGEN GAS. 532 00:19:40,760 --> 00:19:42,800 THIS IS KIND OF CAUSTIC SODA 533 00:19:42,800 --> 00:19:45,960 BUBBLING WITH HYDROGEN GAS. 534 00:19:45,960 --> 00:19:46,880 THEY BUBBLE BACK UP TO THE 535 00:19:46,880 --> 00:19:48,280 BOTTOM OF THE OCEAN AND THERE, 536 00:19:48,280 --> 00:19:50,720 THEY REACT WITH THE OCEAN WATERS 537 00:19:50,720 --> 00:19:52,120 AND PRECIPITATE THESE 538 00:19:52,120 --> 00:19:52,960 HYDROTHERMAL SYSTEMS. 539 00:19:52,960 --> 00:19:55,320 AND THEY'RE FOUND NOT ONLY ON 540 00:19:55,320 --> 00:19:58,920 EARTH BUT WE KNOW THESE PLUMES, 541 00:19:58,920 --> 00:20:03,920 FOR EXAMPLE, ON ENCELADUS, THEY 542 00:20:03,920 --> 00:20:06,960 ARE ALKALINE AND HYDROGEN RICH, 543 00:20:06,960 --> 00:20:09,080 THEY CONTAIN ORGANICS, IT SEEMS 544 00:20:09,080 --> 00:20:14,960 ALMOST CERTAIN NOW, BEE KNEAD 545 00:20:14,960 --> 00:20:16,960 THE CRUST, THERE IS HYDROTHERMAL 546 00:20:16,960 --> 00:20:18,280 SYSTEMS LIKE THESE ONES ON EARTH 547 00:20:18,280 --> 00:20:22,320 THAT I'M TALKING ABOUT THAT I 548 00:20:22,320 --> 00:20:23,200 THINK WHERE THE ENVIRONMENT -- 549 00:20:23,200 --> 00:20:24,120 WHERE LIFE STARTED. 550 00:20:24,120 --> 00:20:26,320 WE FIND THEM AS WELL PROBABLY ON 551 00:20:26,320 --> 00:20:28,280 ANY TRACES OF METHANE FOUND ON 552 00:20:28,280 --> 00:20:30,360 MARS, IF THEY REALLY DO EXIST, 553 00:20:30,360 --> 00:20:32,760 ARE ALMOST CERTAINLY THESE SAME 554 00:20:32,760 --> 00:20:34,960 KIND OF REACTIONS BETWEEN TRACES 555 00:20:34,960 --> 00:20:39,200 OF WATER AND MINERALS LIKE -- ON 556 00:20:39,200 --> 00:20:39,400 MARS. 557 00:20:39,400 --> 00:20:40,280 SO THESE ARE PROCESSS THAT 558 00:20:40,280 --> 00:20:43,080 SHOULD HAPPEN ON ANY WET, ROCKY 559 00:20:43,080 --> 00:20:45,120 PLANET OR MOON AND ARE COMMON 560 00:20:45,120 --> 00:20:47,360 EVEN IN OUR OWN SOLAR SYSTEM AND 561 00:20:47,360 --> 00:20:50,400 SHOULD HAPPEN PROBABLY TENS OF 562 00:20:50,400 --> 00:20:52,960 BILLIONS OF PLANETS IN THE MILKY 563 00:20:52,960 --> 00:20:55,760 WAY ALONE. 564 00:20:55,760 --> 00:20:57,000 THE IDEA THAT LIFE MIGHT HAVE 565 00:20:57,000 --> 00:20:58,720 STARTED IN THESE ENVIRONMENTS 566 00:20:58,720 --> 00:21:03,360 WAS FIRST PUT FORWARD BY MIKE 567 00:21:03,360 --> 00:21:05,120 RUSSELL BACK IN THE EARLY 568 00:21:05,120 --> 00:21:06,320 1990s. 569 00:21:06,320 --> 00:21:07,320 HE'S BEEN PIONEERING THESE 570 00:21:07,320 --> 00:21:08,480 IDEAS, I DON'T ALWAYS AGREE WITH 571 00:21:08,480 --> 00:21:11,440 WHAT HE HAS TO SAY BUT HE'S HAD 572 00:21:11,440 --> 00:21:12,720 ABSOLUTELY STUPENDOUS IDEAS. 573 00:21:12,720 --> 00:21:14,760 I'M WHITTLING THIS DOWN TO HIS 574 00:21:14,760 --> 00:21:17,000 KEY POINTS. 575 00:21:17,000 --> 00:21:19,520 HE SEES ELECTROCHEMICAL FLOW 576 00:21:19,520 --> 00:21:21,160 REACTORS, FLUID PERCOLATING 577 00:21:21,160 --> 00:21:22,960 THROUGH THIS LABYRINTH OF MICRO 578 00:21:22,960 --> 00:21:24,400 PORES WITH CATALYTIC WALLS. 579 00:21:24,400 --> 00:21:25,880 THE CATALYSTS IN THESE WALLS, IN 580 00:21:25,880 --> 00:21:27,600 THE EARLY OCEANS, WHEN THERE WAS 581 00:21:27,600 --> 00:21:29,120 NO OXYGEN AND LOTS OF IRON 582 00:21:29,120 --> 00:21:31,400 AROUND, WERE PROBABLY IRON 583 00:21:31,400 --> 00:21:34,920 SULFIDE MINERALS, PLENTY OF 584 00:21:34,920 --> 00:21:35,920 OTHER THINGS IN THERE AS WELL, 585 00:21:35,920 --> 00:21:39,520 SO WE HAVE ALKALINE FLUIDS, WARM 586 00:21:39,520 --> 00:21:40,960 ALKALINE FLUIDS BUBBLING, 587 00:21:40,960 --> 00:21:42,480 INTERACTING WITH THESE CATALYTIC 588 00:21:42,480 --> 00:21:44,720 WALLS AND OCEAN WATER AS WELL, 589 00:21:44,720 --> 00:21:46,760 PERCOLATING IN, FULL OF CO2, 590 00:21:46,760 --> 00:21:50,520 SATURATED IN CO2, AND IN SOME 591 00:21:50,520 --> 00:21:52,320 WAY, THIS ELECTROCHEMICAL FLOW 592 00:21:52,320 --> 00:21:53,320 REACTOR IS GOING TO DRIVE THE 593 00:21:53,320 --> 00:21:54,320 ORIGIN OF LIFE. 594 00:21:54,320 --> 00:21:55,320 THAT'S WHAT I'M GOING TO TRY AND 595 00:21:55,320 --> 00:21:56,720 TELL YOU IN THE REST OF THIS 596 00:21:56,720 --> 00:22:00,160 TALK. 597 00:22:00,160 --> 00:22:03,840 SO THESE VENT PORES ARE 598 00:22:03,840 --> 00:22:04,320 ANALOGOUS TO CELLS. 599 00:22:04,320 --> 00:22:06,360 THIS IS MY SIMPLE ATTEMPT TO 600 00:22:06,360 --> 00:22:07,800 CONVEY WHAT A BACTERIAL CELL 601 00:22:07,800 --> 00:22:09,600 LOOKS LIKE ATITY MOST ELEMENTARY 602 00:22:09,600 --> 00:22:10,200 LEVEL. 603 00:22:10,200 --> 00:22:12,520 IT BASICALLY GOT A MEMBRANE PUMP 604 00:22:12,520 --> 00:22:15,000 HERE IN THE MEMBRANE, PUMPING 605 00:22:15,000 --> 00:22:17,240 PROTONS OUT, SO WE HAVE A PROTON 606 00:22:17,240 --> 00:22:18,400 GRADIENT ACROSS THIS MEMBRANE. 607 00:22:18,400 --> 00:22:22,920 IT'S RELATIVELY ALKALINE INSIDE, 608 00:22:22,920 --> 00:22:24,240 OF COURSE PUTTING A CHARGE ON 609 00:22:24,240 --> 00:22:25,200 THIS MEMBRANE BECAUSE THE 610 00:22:25,200 --> 00:22:27,320 PROTONS ARE MOVING OUT. 611 00:22:27,320 --> 00:22:29,640 AND HERE WE HAVE AN INORGANIC 612 00:22:29,640 --> 00:22:31,760 BARRIER, THICK IN COMPARISON, WE 613 00:22:31,760 --> 00:22:33,320 HAVE ACIDIC OCEAN WATERS 614 00:22:33,320 --> 00:22:34,680 PERCOLATING IN AND WE HAVE 615 00:22:34,680 --> 00:22:35,120 ALKALINE FLUIDS. 616 00:22:35,120 --> 00:22:38,360 SO WE HAVE A SIMILAR PH 617 00:22:38,360 --> 00:22:40,320 DIFFERENCE, SIMILAR MAGNITUDE OF 618 00:22:40,320 --> 00:22:41,720 PROBABLY PH UNITS AND IT SHOULD 619 00:22:41,720 --> 00:22:44,960 ALSO BE SIMILAR IN POLARITY. 620 00:22:44,960 --> 00:22:47,720 IT'S EFFECTIVELY ACID OUTSIDE, 621 00:22:47,720 --> 00:22:48,680 ALKALINE INSIDE. 622 00:22:48,680 --> 00:22:49,800 IS THIS JUST IMAGINATION? 623 00:22:49,800 --> 00:22:51,320 AM I SEEING THINGS HERE, OR CAN 624 00:22:51,320 --> 00:22:53,160 WE COME UP WITH A WAY OF GOING 625 00:22:53,160 --> 00:22:55,120 FROM THIS SIMPLE INORGANIC 626 00:22:55,120 --> 00:22:58,720 SYSTEM TO THE WAY THAT CELLS 627 00:22:58,720 --> 00:22:59,800 WORK? 628 00:22:59,800 --> 00:23:01,040 I'M ACTUALLY FOLLOWING HERE IN 629 00:23:01,040 --> 00:23:03,840 THE FOOTSTEPS OF PETER MITCHELL 630 00:23:03,840 --> 00:23:04,920 HIMSELF WHO DID WONDER AND WORK 631 00:23:04,920 --> 00:23:06,240 A LITTLE BIT ON THE ORIGIN OF 632 00:23:06,240 --> 00:23:07,720 LIFE, SO MITCHELL'S IDEAS, HE 633 00:23:07,720 --> 00:23:08,920 WAS THE PERSON WHO CAME UP WITH 634 00:23:08,920 --> 00:23:15,040 THESE IDEAS OF COUPLING AND 635 00:23:15,040 --> 00:23:15,800 MEMBRANE BIOGENETICS. 636 00:23:15,800 --> 00:23:16,920 THEY DIDN'T GO OVER WELL AT THE 637 00:23:16,920 --> 00:23:17,280 TIME. 638 00:23:17,280 --> 00:23:19,920 THERE'S A LOVELY QUOTE, NOT 639 00:23:19,920 --> 00:23:21,720 SINCE DARWIN HAS BIOLOGY COME UP 640 00:23:21,720 --> 00:23:26,440 WITH AN IDEA THAT'S AS 641 00:23:26,440 --> 00:23:27,960 COUNTERINTUITIVE, AND IT WAS 642 00:23:27,960 --> 00:23:30,320 REALLY JENNIFER MOYLE WHO DID 643 00:23:30,320 --> 00:23:31,800 THE PIONEERING EXPERIMENTS. 644 00:23:31,800 --> 00:23:33,200 MITCHELL HIMSELF WAS QUITE 645 00:23:33,200 --> 00:23:36,000 CANDID IN THE LAB, AND IT WAS 646 00:23:36,000 --> 00:23:38,720 JENNIFER MOYLE WHO DID THE 647 00:23:38,720 --> 00:23:41,960 EXPERIMENTS THAT DEMONSTRATED TO 648 00:23:41,960 --> 00:23:43,520 INITIALLY A VERY SKEPTICAL WORLD 649 00:23:43,520 --> 00:23:44,440 THAT THERE WAS SOMETHING IN 650 00:23:44,440 --> 00:23:46,520 THESE IDEAS. 651 00:23:46,520 --> 00:23:48,920 MITCHELL HIMSELF WAS QUITE 652 00:23:48,920 --> 00:23:49,720 PHILOSOPHICALLY-MINDED. 653 00:23:49,720 --> 00:23:52,120 HERE'S A QUOTE WHICH I THINK IS 654 00:23:52,120 --> 00:23:54,920 BEAUTIFUL, HE SAYS, I CANNOT 655 00:23:54,920 --> 00:23:57,920 CONSIDER THE ORGANISM WITHOUT 656 00:23:57,920 --> 00:23:58,520 THIS ENVIRONMENT. 657 00:23:58,520 --> 00:24:00,200 FROM A FORMAL POINT OF VIEW, THE 658 00:24:00,200 --> 00:24:01,920 TWO MAY BE REGARDED AS 659 00:24:01,920 --> 00:24:07,960 EQUIVALENT PHASES BETWEEN WHICH 660 00:24:07,960 --> 00:24:11,520 DYNAMIC CONTACT IS MAINTAINED BY 661 00:24:11,520 --> 00:24:13,040 THE MEMBRANES THAT SEPARATE AND 662 00:24:13,040 --> 00:24:18,040 LINK THEM. 663 00:24:18,040 --> 00:24:19,280 SEPARATING THESE TWO DIFFERENT 664 00:24:19,280 --> 00:24:20,480 PHASES. 665 00:24:20,480 --> 00:24:21,240 NOW THE ORIGIN OF LIFE, THERE 666 00:24:21,240 --> 00:24:22,960 ISN'T SUCH A THING YET AS A CELL 667 00:24:22,960 --> 00:24:25,200 OR AS LIFE OR AS LIVING THINGS. 668 00:24:25,200 --> 00:24:28,080 THESE TWO PHASES WITH A BARRIER 669 00:24:28,080 --> 00:24:29,320 SEPARATING THEM MAKES MUCH MORE 670 00:24:29,320 --> 00:24:32,640 SENSE WHEN WE'RE THINKING ABOUT 671 00:24:32,640 --> 00:24:33,120 THE ORIGIN OF LIFE. 672 00:24:33,120 --> 00:24:34,920 WE'RE BEGINNING TO SEE HOW THE 673 00:24:34,920 --> 00:24:37,920 SYSTEM CAN ITSELF BE 674 00:24:37,920 --> 00:24:47,080 COMPARTMENTALIZED. 675 00:24:47,080 --> 00:24:48,320 SO MITCHELL WAS ASKING A VERY 676 00:24:48,320 --> 00:24:49,800 SIMPLE QUESTION, WHICH WAS CASE 677 00:24:49,800 --> 00:24:53,720 BACEICALLY, HOW WAS 678 00:24:53,720 --> 00:24:56,120 BASICALLY, HOW DO BACTERIA KEEP 679 00:24:56,120 --> 00:24:57,520 THESE TWO PHASES DIFFERENT? 680 00:24:57,520 --> 00:24:59,120 AND HE RECOGNIZED THAT WHILE 681 00:24:59,120 --> 00:25:02,760 THEY HAVE TO FIND PARTICULAR 682 00:25:02,760 --> 00:25:04,440 MOLECULES, PROTONS IN THIS CASE, 683 00:25:04,440 --> 00:25:05,960 RECOGNIZE THEM, THEN PHYSICALLY 684 00:25:05,960 --> 00:25:07,360 PUMP THEM OUT, THAT'S GOING TO 685 00:25:07,360 --> 00:25:08,000 COST ENERGY. 686 00:25:08,000 --> 00:25:11,520 THEN CONVERSELY, IT WILL -- 687 00:25:11,520 --> 00:25:13,480 YOU'LL BE ABLE TO TAP THAT 688 00:25:13,480 --> 00:25:14,720 ENERGY, IF YOU CAN CONSERVE THAT 689 00:25:14,720 --> 00:25:15,800 ENERGY AS THEY ALLOW THEM TO 690 00:25:15,800 --> 00:25:17,560 FLOW BACK IN AGAIN, YOU'LL BE 691 00:25:17,560 --> 00:25:18,400 ABLE TO POWER WORK. 692 00:25:18,400 --> 00:25:19,400 AND MOSTLY WHEN WE THINK ABOUT 693 00:25:19,400 --> 00:25:21,440 THAT WORK, WE'RE THINKING ABOUT 694 00:25:21,440 --> 00:25:22,120 ATP SYNTHESIS. 695 00:25:22,120 --> 00:25:24,120 BUT IT'S NOT ONLY ATP SYNTHESIS. 696 00:25:24,120 --> 00:25:26,080 IN BACTERIA, VERY OFTEN THE 697 00:25:26,080 --> 00:25:28,440 PROTON GRADIENTS ARE DRIVING CO2 698 00:25:28,440 --> 00:25:30,280 FIXATION, AND THAT, TO ME, IS 699 00:25:30,280 --> 00:25:31,880 THE KEY TO THINKING ABOUT THIS. 700 00:25:31,880 --> 00:25:34,920 SO THE MOST ANCIENT CELLS THAT 701 00:25:34,920 --> 00:25:36,680 WE KNOW ABOUT GREW FROM HYDROGEN 702 00:25:36,680 --> 00:25:37,760 AND CO2. 703 00:25:37,760 --> 00:25:39,560 AND THEY'RE FIXING CO2 AND TO DO 704 00:25:39,560 --> 00:25:43,720 THAT, THEY REQUIRE, THEY'RE 705 00:25:43,720 --> 00:25:46,720 FULLY DEPENDENT ON COUPLING. 706 00:25:46,720 --> 00:25:52,880 SO THESE CELLS AND METHANOGENS 707 00:25:52,880 --> 00:25:56,240 AND ACETOGENS, THIS IS THE ONLY 708 00:25:56,240 --> 00:25:58,240 PATHWAY FOUND IN BOTH BACTERIA 709 00:25:58,240 --> 00:26:00,960 AND ARCHAEA, IT'S BASICALLY A 710 00:26:00,960 --> 00:26:04,960 REACTION BETWEEN CO2 AND 711 00:26:04,960 --> 00:26:05,720 HYDROGEN. 712 00:26:05,720 --> 00:26:07,240 SO THESE ARE THE GASES WE HAVE 713 00:26:07,240 --> 00:26:09,600 IN THESE VENTS. 714 00:26:09,600 --> 00:26:12,280 WHEN THEY WORK TOGETHER, TO 715 00:26:12,280 --> 00:26:18,360 PRODUCE METHANE AS A BYPRODUCT, 716 00:26:18,360 --> 00:26:23,240 AND -- IT'S OVERALL EXOGONIC BUT 717 00:26:23,240 --> 00:26:24,640 THEY DON'T REACT VERY EASILY. 718 00:26:24,640 --> 00:26:26,400 THEY NEED A PROTON GRADIENT 719 00:26:26,400 --> 00:26:28,120 ACROSS A MEMBRANE TO DRIVE THOSE 720 00:26:28,120 --> 00:26:28,520 FIRST FEW STEPS. 721 00:26:28,520 --> 00:26:30,080 AND WHAT THEY'RE DOING IS USING 722 00:26:30,080 --> 00:26:31,400 A MEMBRANE PROTEIN, IN THIS 723 00:26:31,400 --> 00:26:36,320 CASE, THE ENERGY CONVERTING HIGH 724 00:26:36,320 --> 00:26:43,320 HYDROGENASE TO REDUCE FAIR -- TO MAKE 725 00:26:43,320 --> 00:26:43,960 ORGANIC MOLECULES. 726 00:26:43,960 --> 00:26:47,720 SO IT TAKING THE ELECTRONS FROM 727 00:26:47,720 --> 00:26:48,680 HYDROGEN, MAKING ORGANIC 728 00:26:48,680 --> 00:26:49,440 MOLECULES. 729 00:26:49,440 --> 00:26:55,800 THAT DOESN'T HAPPEN 730 00:26:55,800 --> 00:26:57,000 SPONTANEOUSLY, TO DRIVE THAT. 731 00:26:57,000 --> 00:26:58,880 AND THIS SLIGHTLY MORE COMPLEX 732 00:26:58,880 --> 00:27:00,160 DIAGRAM, I WOULDN'T TRY AND 733 00:27:00,160 --> 00:27:02,280 EXPLAIN IT TO YOU, BUT IT'S 734 00:27:02,280 --> 00:27:04,920 ESSENTIALLY SAYING THAT FIRST 735 00:27:04,920 --> 00:27:06,720 STEP IS ELECTROCHEMICALLY NOT 736 00:27:06,720 --> 00:27:08,880 FAVORED, THERE'S A DIFFERENCE OF 737 00:27:08,880 --> 00:27:10,320 ABOUT 200 MILLIVOLTS THAT NEED 738 00:27:10,320 --> 00:27:11,760 TO BE OVERCOME TO DRIVE THAT 739 00:27:11,760 --> 00:27:12,600 REACTION. 740 00:27:12,600 --> 00:27:14,840 WHEN YOU HAVE GOT THROUGH THAT 741 00:27:14,840 --> 00:27:16,960 STEP, WE GET INTO THE CORE OF 742 00:27:16,960 --> 00:27:19,760 BIOCHEMISTRY AS WE KNOW IT 743 00:27:19,760 --> 00:27:20,960 ALMOST IMMEDIATELY. 744 00:27:20,960 --> 00:27:22,120 SO DON'T WORRY ABOUT THE DETAILS 745 00:27:22,120 --> 00:27:23,240 ON THIS SLIDE. 746 00:27:23,240 --> 00:27:25,400 WHAT I'D LIKE YOU TO NOTICE IS 747 00:27:25,400 --> 00:27:26,520 THE HYDROGEN IS IN BROWN. 748 00:27:26,520 --> 00:27:27,920 STARTING WITH CO2 IN THIS 749 00:27:27,920 --> 00:27:30,080 CORNER, WE'VE GOT HYDROGEN, 750 00:27:30,080 --> 00:27:32,640 HYDROGEN, HYDROGEN, THROUGH TO A 751 00:27:32,640 --> 00:27:35,280 METHYL GROUP, MORE HYDROGEN TO 752 00:27:35,280 --> 00:27:38,520 MAKE CARBON DIOXIDE, AN 753 00:27:38,520 --> 00:27:42,720 ACTIVATED ACETYL GROUP, THROUGH 754 00:27:42,720 --> 00:27:45,280 TO GLYCINE PRETTY QUICKLY AS 755 00:27:45,280 --> 00:27:48,720 WELL, MORE CO2, MORE HYDROGEN. 756 00:27:48,720 --> 00:27:53,520 IS A LOW THIS IS THE KREBS CYCLE. 757 00:27:53,520 --> 00:27:54,800 NOT THE KREBS CYCLE AS MOST 758 00:27:54,800 --> 00:27:58,720 PEOPLE KNOW IT, AS AN OXIDATIVE 759 00:27:58,720 --> 00:28:00,120 PROCESS, BUT THE REVERSE KREBS 760 00:28:00,120 --> 00:28:01,600 CYCLE OR THESE FIRST STEPS ARE 761 00:28:01,600 --> 00:28:04,560 BASICALLY TAKING HYDROGEN AND 762 00:28:04,560 --> 00:28:05,720 CO2 FROM THE ENVIRONMENT, 763 00:28:05,720 --> 00:28:07,040 REACTING THEM TOGETHER TO MAKE 764 00:28:07,040 --> 00:28:09,320 KREBS CYCLE INTERMEDIATES. 765 00:28:09,320 --> 00:28:11,760 THOSE ARE USED TO MAKE AMINO 766 00:28:11,760 --> 00:28:13,040 ACIDS. 767 00:28:13,040 --> 00:28:16,240 THEY'RE USED TO MAKE SUGARS FROM 768 00:28:16,240 --> 00:28:20,320 PIE 769 00:28:20,320 --> 00:28:21,920 PYRUVATE, TO MAKE AN ENERGY 770 00:28:21,920 --> 00:28:24,080 CURRENCY, IN THIS CASE, ACETYL 771 00:28:24,080 --> 00:28:24,320 PHOSPHATE. 772 00:28:24,320 --> 00:28:25,440 NOW THE RED BOXES HERE, THESE 773 00:28:25,440 --> 00:28:31,040 ARE THE PRECURSORS FOR AGAIN, 774 00:28:31,040 --> 00:28:35,720 WE'RE BEGINNING TO MAKE -- 775 00:28:35,720 --> 00:28:38,400 REALLY VERY CLOSE TO THE CENTRAL 776 00:28:38,400 --> 00:28:39,520 METABOLISM. 777 00:28:39,520 --> 00:28:41,520 THE VERY CORE FROM THIS AUTO 778 00:28:41,520 --> 00:28:42,400 TROPHIC POINT OF VIEW IS 779 00:28:42,400 --> 00:28:44,440 HYDROGEN AND CO2 PRODUCING THESE 780 00:28:44,440 --> 00:28:45,440 CARBON SKELETON RIGHT AT THE 781 00:28:45,440 --> 00:28:47,480 HEART OF METABOLISM. 782 00:28:47,480 --> 00:28:49,520 MOST OF IT, ALMOST ALL OF THESE 783 00:28:49,520 --> 00:28:52,840 STEPS ARE ACTUALLY EXOTHERMIC. 784 00:28:52,840 --> 00:28:55,680 THEY WILL -- IF YOU START WITH 785 00:28:55,680 --> 00:28:59,520 HIDE JENS AND -- WARM THEM UP TO 786 00:28:59,520 --> 00:29:00,800 50 DEGREES CENTIGRADE, AS YOU 787 00:29:00,800 --> 00:29:03,520 CAN SEE ACROSS THE X AXIS HERE, 788 00:29:03,520 --> 00:29:05,720 THE TOTAL CELL BIOMASS RELEASES 789 00:29:05,720 --> 00:29:06,640 ENERGY. 790 00:29:06,640 --> 00:29:07,720 THIS IS FREE ENERGY. 791 00:29:07,720 --> 00:29:09,480 IT'S QUITE STRONGLY EXOTHERMIC. 792 00:29:09,480 --> 00:29:12,120 IF WE SHAKE HYDROGEN AND CO2, WE 793 00:29:12,120 --> 00:29:14,680 SHOULD GET CELLS DROPPING OUT. 794 00:29:14,680 --> 00:29:16,440 THE THERMODYNAMICS, THAT SHOULD 795 00:29:16,440 --> 00:29:16,680 HAPPEN. 796 00:29:16,680 --> 00:29:21,080 OF COURSE IT DOESN'T HAPPEN. 797 00:29:21,080 --> 00:29:24,720 THE MOST FAVORITE OF THE AMINO 798 00:29:24,720 --> 00:29:26,840 ACIDS, NUCLEOTIDES COST SOME 799 00:29:26,840 --> 00:29:29,720 ENERGIES TO MAYBE, BUT REALLY 800 00:29:29,720 --> 00:29:32,720 THE ENERGETICALLY FAVORED STATE 801 00:29:32,720 --> 00:29:34,600 OF CELLS IS HARD TO FATHOM, BUT 802 00:29:34,600 --> 00:29:37,560 IT'S THE TRUTH. 803 00:29:37,560 --> 00:29:39,280 THE REASON IT DOESN'T HAPPEN 804 00:29:39,280 --> 00:29:40,200 SPONTANEOUSLY IS THIS BARRIER 805 00:29:40,200 --> 00:29:43,080 HERE TO THE REACTION, TO GET 806 00:29:43,080 --> 00:29:44,120 THROUGH THE FIRST COUPLE OF 807 00:29:44,120 --> 00:29:45,800 STEPS TO FORMALDEHYDE, IT'S 808 00:29:45,800 --> 00:29:46,160 UPHILL. 809 00:29:46,160 --> 00:29:47,600 AND THEN AFTER THAT, IT'S 810 00:29:47,600 --> 00:29:48,280 DOWNHILL ALL THE WAY. 811 00:29:48,280 --> 00:29:52,200 AND THIS IS THE KIND OF THE 812 00:29:52,200 --> 00:29:54,320 REDOX ZONE OF ORGANIC CHEMISTRY 813 00:29:54,320 --> 00:29:54,720 INSIDE CELLS. 814 00:29:54,720 --> 00:29:56,960 IT'S JUST SLIGHTLY LOWER THAN 815 00:29:56,960 --> 00:30:02,240 CO2 ITSELF. 816 00:30:02,240 --> 00:30:07,520 THE METHANOGENS ARE USING A 817 00:30:07,520 --> 00:30:08,400 PROTON GRADIENT, DRIVING THE 818 00:30:08,400 --> 00:30:09,920 REACTION BETWEEN CO2 AND 819 00:30:09,920 --> 00:30:10,320 HYDROGEN. 820 00:30:10,320 --> 00:30:11,120 THE QUESTION IS, IS THIS 821 00:30:11,120 --> 00:30:12,520 SOMETHING THAT CAN HAPPEN IN A 822 00:30:12,520 --> 00:30:13,320 PREBITE IK ENVIRONMENT AND THE 823 00:30:13,320 --> 00:30:14,760 ANSWER IS YES, IT'S SIMPLE 824 00:30:14,760 --> 00:30:15,320 PHYSICAL CHEMISTRY. 825 00:30:15,320 --> 00:30:19,000 THE PROBLEM HERE IS THAT HIDE 826 00:30:19,000 --> 00:30:32,480 JEB, IF YOU HEIDI -- 827 00:30:32,480 --> 00:30:35,360 THAT'S A PH7 OR ANY OTHER PH. 828 00:30:35,360 --> 00:30:37,400 IN THE VENTS, HYDROGEN IS 829 00:30:37,400 --> 00:30:42,120 BUBBLING OUT OF THE GROUND AT 830 00:30:42,120 --> 00:30:43,560 PH11 IN -- THE REACTION 831 00:30:43,560 --> 00:30:45,400 POTENTIAL IS MUCH LOWER. 832 00:30:45,400 --> 00:30:47,800 CO2 IS PERCOLATING IN WITH THE 833 00:30:47,800 --> 00:30:52,120 ACYTIC OCEAN WATERS, THESE EARLY 834 00:30:52,120 --> 00:30:52,960 ACETIC OCEANS. 835 00:30:52,960 --> 00:30:54,320 YOU CAN THINK OF IT REALLY 836 00:30:54,320 --> 00:30:54,840 EASILY. 837 00:30:54,840 --> 00:30:57,720 IF A HYDROGEN PUSHES ITS 838 00:30:57,720 --> 00:31:00,120 ELECTRONS ON TO SOMETHING ELSE, 839 00:31:00,120 --> 00:31:01,040 WHAT'S LEFT BEHIND? 840 00:31:01,040 --> 00:31:02,520 THE PROTONS ARE LEFT BEHIND. 841 00:31:02,520 --> 00:31:07,360 IN AN ALKALINE ENVIRONMENT, THE THIS 842 00:31:07,360 --> 00:31:08,960 IS A PHYSICIANING NEUTRALIZATION 843 00:31:08,960 --> 00:31:15,520 REACTION FIZZING REACTION, THERE'S 844 00:31:15,520 --> 00:31:17,080 NO WAY YOU CAN STOP IT FROM 845 00:31:17,080 --> 00:31:19,040 HAPPENING. 846 00:31:19,040 --> 00:31:21,440 THE MORE -- IN AN ACIDIC 847 00:31:21,440 --> 00:31:22,520 ENVIRONMENT, YOU'RE RELEASING 848 00:31:22,520 --> 00:31:26,640 PROTONS INTO THE ACYTIC 849 00:31:26,640 --> 00:31:26,920 ENVIRONMENT. 850 00:31:26,920 --> 00:31:28,080 IF THERE'S A PROTON AVAILABLE, 851 00:31:28,080 --> 00:31:29,960 IT BALANCES THE CHARGE, IT CAN 852 00:31:29,960 --> 00:31:33,960 NOW PICK UP ANOTHER -- IT'S EASY 853 00:31:33,960 --> 00:31:35,920 TO PRODUCE CO2 IN AN ACIDIC 854 00:31:35,920 --> 00:31:36,280 ENVIRONMENT. 855 00:31:36,280 --> 00:31:38,520 THIS IS JUST FORMALIZED. 856 00:31:38,520 --> 00:31:43,080 THE DIFFERENCE IS ABOUT 60 MILL 857 00:31:43,080 --> 00:31:47,720 EE VOLTS, SOCK WHAT WE HAVE IN 858 00:31:47,720 --> 00:31:51,160 THESE VENTS IS MORE REACTIVE. 859 00:31:51,160 --> 00:31:53,480 OCEAN WATERS, MORE REACTIVE, SO 860 00:31:53,480 --> 00:31:55,760 AS LONG AS THEY STAY AS TWO 861 00:31:55,760 --> 00:31:57,400 PHASES SEPARATED BY SOME KIND OF 862 00:31:57,400 --> 00:31:59,280 A BARRIER, A MEMBRANE OF SOME 863 00:31:59,280 --> 00:32:00,920 SORT, THEN THERE SHOULD BE 864 00:32:00,920 --> 00:32:01,640 REACTION. 865 00:32:01,640 --> 00:32:03,200 THIS MIM BRAIN NEEDS TO SEPARATE 866 00:32:03,200 --> 00:32:05,160 AND LINK, REMEMBER WHAT PETER 867 00:32:05,160 --> 00:32:09,440 MITCHELL SAID, IT NEEDS TO BE 868 00:32:09,440 --> 00:32:14,040 SEPARATED AND -- -- ACROSS THE 869 00:32:14,040 --> 00:32:14,480 BARRIER. 870 00:32:14,480 --> 00:32:17,200 SO I CAN IMAGINE, I'M NOW GOING 871 00:32:17,200 --> 00:32:19,760 TO SUGGEST A MECHANISM AND THEN 872 00:32:19,760 --> 00:32:20,840 I'LL TALK ABOUT HOW WE CAN TEST 873 00:32:20,840 --> 00:32:22,040 IN THE LAB. 874 00:32:22,040 --> 00:32:28,320 I CAN IMAGINE, HERE IS A -- I'VE 875 00:32:28,320 --> 00:32:29,440 GOT PROTONS CROSSING THIS 876 00:32:29,440 --> 00:32:30,840 BARRIER AND DRIVING THE REACTION 877 00:32:30,840 --> 00:32:33,040 BETWEEN HYDROGEN AND CO2, AND 878 00:32:33,040 --> 00:32:34,200 THE PROTONS ARE PERPETUALLY 879 00:32:34,200 --> 00:32:36,320 BEING FED IN FROM THE OCEANS, 880 00:32:36,320 --> 00:32:38,920 HYDROXIDE IONS AND HYDROGEN 881 00:32:38,920 --> 00:32:41,880 PERPETUALLY FED IN, IN THE -- 882 00:32:41,880 --> 00:32:43,840 THIS IS NOT FORMALDEHYDE, THIS 883 00:32:43,840 --> 00:32:45,960 IS SUPPOSED TO BE ORGANIC 884 00:32:45,960 --> 00:32:46,800 MOLECULES IN GENERAL. 885 00:32:46,800 --> 00:32:49,120 THE LOGICAL END POINT IS WE END 886 00:32:49,120 --> 00:32:54,160 UP WITH SOMETHING WITH FATTY 887 00:32:54,160 --> 00:32:55,720 ACID MEMBRANES SURROUNDING IT. 888 00:32:55,720 --> 00:32:57,320 SO THIS IS HOW I CAN IMAGINE THE 889 00:32:57,320 --> 00:32:58,240 PROCESS MIGHT WORK. 890 00:32:58,240 --> 00:33:00,640 QUESTION IS, AM I MAD? 891 00:33:00,640 --> 00:33:02,440 AND THE ANSWER IS, WELL, QUITE 892 00:33:02,440 --> 00:33:03,560 POSSIBLY YOU CAN ASK ME THAT 893 00:33:03,560 --> 00:33:06,520 LATER ON, BUT WE CAN AT LEAST 894 00:33:06,520 --> 00:33:07,160 TEST IT. 895 00:33:07,160 --> 00:33:08,400 WE'RE NOW INTO SCIENCE. 896 00:33:08,400 --> 00:33:10,000 I'VE BEEN TRYING TO TEST SOME OF 897 00:33:10,000 --> 00:33:12,840 THESE IDEAS FOR MORE THAN A 898 00:33:12,840 --> 00:33:13,080 DECADE. 899 00:33:13,080 --> 00:33:14,120 THIS WAS ONE OF THE FIRST 900 00:33:14,120 --> 00:33:15,040 REACTORS THAT WE BUILT, AND YOU 901 00:33:15,040 --> 00:33:16,360 CAN SEE IT WAS VERY HOMEMADE AND 902 00:33:16,360 --> 00:33:17,520 IT DIDN'T WORK VERY WELL. 903 00:33:17,520 --> 00:33:19,160 WE TRIED PRECIPITATING ALL KINDS 904 00:33:19,160 --> 00:33:20,920 OF VENT-LIKE STRUCTURES INSIDE 905 00:33:20,920 --> 00:33:22,080 THIS AND THEY DIDN'T WORK VERY 906 00:33:22,080 --> 00:33:22,880 WELL EITHER. 907 00:33:22,880 --> 00:33:28,000 WE ENDED UP DOING A MICRO -- BUT 908 00:33:28,000 --> 00:33:32,000 I 909 00:33:32,000 --> 00:33:34,920 IRONICALLY, A PH.D. STUDENT FROM 910 00:33:34,920 --> 00:33:36,120 MY LAB LEFT AND NAILS THIS A 911 00:33:36,120 --> 00:33:38,320 YEAR OR TWO AGO. 912 00:33:38,320 --> 00:33:43,720 ON THE LEFT-HAND SIDE HERE, 913 00:33:43,720 --> 00:33:46,520 THERE'S A BARRIER -- WHICH CROSS 914 00:33:46,520 --> 00:33:48,600 THE BARRIER TO REDUCE CO2 AT THE 915 00:33:48,600 --> 00:33:51,520 OTHER SIDE IN AN ACYTIC 916 00:33:51,520 --> 00:33:51,960 SOLUTION. 917 00:33:51,960 --> 00:33:55,040 I WON'T GO THROUGH THE NMR DATA 918 00:33:55,040 --> 00:33:56,520 WITH YOU, BUT BASICALLY WHAT 919 00:33:56,520 --> 00:34:00,200 IT'S SHOWING YOU, IN 13C NMR AND 920 00:34:00,200 --> 00:34:03,800 DEUT R 921 00:34:03,800 --> 00:34:13,880 AND D UTERONS, IS THE -- FROM 922 00:34:13,880 --> 00:34:17,120 THE ACIDIC SIDE. 923 00:34:17,120 --> 00:34:19,000 IT REQUIRES A PH GRADIENT, SO IT 924 00:34:19,000 --> 00:34:20,280 REALLY DOES REQUIRE THIS PH 925 00:34:20,280 --> 00:34:21,400 DIFFERENCE IF YOU DON'T HAVE 926 00:34:21,400 --> 00:34:22,720 THAT PH GAP THERE, THEN IT 927 00:34:22,720 --> 00:34:23,280 DOESN'T WORK. 928 00:34:23,280 --> 00:34:25,080 IF YOU DON'T HAVE THE BARRIER, 929 00:34:25,080 --> 00:34:26,080 IT DOESN'T WORK. 930 00:34:26,080 --> 00:34:27,520 IF YOU DON'T HAVE HYDROGEN GAS, 931 00:34:27,520 --> 00:34:29,320 IT DOESN'T WORK AND SO ON. 932 00:34:29,320 --> 00:34:31,200 SO IT REQUIRE THIS IS TOPOLOGY, 933 00:34:31,200 --> 00:34:32,440 IT REQUIRES THIS SETUP. 934 00:34:32,440 --> 00:34:34,000 BUT THESE EXPERIMENTS WEREN'T 935 00:34:34,000 --> 00:34:34,360 CLEAR. 936 00:34:34,360 --> 00:34:36,320 IS IT PROTONS OR IS IT ELECTRONS 937 00:34:36,320 --> 00:34:37,520 CROSSING THIS BARRIER? 938 00:34:37,520 --> 00:34:38,720 WE COULDN'T REALLY NAIL WHICH 939 00:34:38,720 --> 00:34:40,880 WAY IT'S GOING. 940 00:34:40,880 --> 00:34:42,600 I'VE BEEN TRYING TO DO THAT, AND 941 00:34:42,600 --> 00:34:43,800 ONE THING THAT STRUCK ME EARLY 942 00:34:43,800 --> 00:34:47,120 ON IS THAT THIS IS A MICRO 943 00:34:47,120 --> 00:34:50,520 FLUIDIC CHIP AND WE'VE GOT ACID 944 00:34:50,520 --> 00:34:52,720 FLOW ON THIS CHANNEL, WE'VE GOT 945 00:34:52,720 --> 00:34:55,120 ALKALINE FLOW IN THIS CHANNEL. 946 00:34:55,120 --> 00:34:56,840 THIS IS LAMINAR FLOW SO THERE'S 947 00:34:56,840 --> 00:34:57,920 NOT MUCH MIXING GOING ON HERE, 948 00:34:57,920 --> 00:34:59,520 THERE'S NO BARRIER HERE AT ALL, 949 00:34:59,520 --> 00:35:01,320 THIS IS JUST THE MIXING ZONE. 950 00:35:01,320 --> 00:35:06,960 AND IF WE ADD FERROUS CHLORIDE 951 00:35:06,960 --> 00:35:09,040 AND SODIUM SULFIDE, THEN WE 952 00:35:09,040 --> 00:35:11,320 PRECIPITATE AN IRON SULFIDE 953 00:35:11,320 --> 00:35:12,200 BARRIER BETWEEN THE TWO. 954 00:35:12,200 --> 00:35:14,000 IT CAN BE A KIND OF DIFFUSE, 955 00:35:14,000 --> 00:35:14,760 WISPY BARRIER. 956 00:35:14,760 --> 00:35:16,960 WE NOTICE IT TENDS TO BE ASSAY 957 00:35:16,960 --> 00:35:19,440 DICK. 958 00:35:19,440 --> 00:35:23,400 SO THEY TEND TO BE ACIDIC. 959 00:35:23,400 --> 00:35:25,440 SO WE LOOK AT THAT A LITTLE MORE 960 00:35:25,440 --> 00:35:26,240 CLOSELY AND HERE YOU CAN SEE 961 00:35:26,240 --> 00:35:28,120 THIS IS THE ALKALINE PHASE, THIS 962 00:35:28,120 --> 00:35:37,920 IS THE THE ACYTIC ACIDIC PHASE. 963 00:35:37,920 --> 00:35:39,320 WE FOUND PROTONS CROSS THIS 964 00:35:39,320 --> 00:35:41,840 BARRIER ABOUT 200 MILLION TIMES 965 00:35:41,840 --> 00:35:43,280 FASTER, SO THESE BARRIERS REALLY 966 00:35:43,280 --> 00:35:44,240 DO TRANSFER PROTONS. 967 00:35:44,240 --> 00:35:47,800 IT'S PROBABLY TO DO WITH THE 968 00:35:47,800 --> 00:35:49,400 STRUCTURE IN THE TRAPPED WATER 969 00:35:49,400 --> 00:35:50,840 IN THE BARRIERS THEMSELVES. 970 00:35:50,840 --> 00:35:52,600 THIS, AT LEAST, IS CONSISTENT 971 00:35:52,600 --> 00:35:57,120 WITH THIS IDEA THAT WE CAN HAVE 972 00:35:57,120 --> 00:35:59,120 PROTONS CROSSING THE BARRIER AND 973 00:35:59,120 --> 00:36:01,080 ENTERING SOME SORT OF PROTO 974 00:36:01,080 --> 00:36:01,720 CELL. 975 00:36:01,720 --> 00:36:04,360 I SAY PROTOCELLS, BUT THIS IS AN 976 00:36:04,360 --> 00:36:05,520 EXTREME ENVIRONMENT. 977 00:36:05,520 --> 00:36:10,240 THIS HAS GOT PH 5 OR 6 IN THE 978 00:36:10,240 --> 00:36:12,280 OCEANS, 10 OR 11 OVER HERE. 979 00:36:12,280 --> 00:36:14,760 ALMOST CERTAINLY, THE EARLY 980 00:36:14,760 --> 00:36:18,880 OCEANS WERE PRETTY SALINE, AND 981 00:36:18,880 --> 00:36:20,480 MAGNESIUM AND CALCIUM AND SO ON. 982 00:36:20,480 --> 00:36:27,040 THESE ARE SUPPOSED TO BE -- MADE 983 00:36:27,040 --> 00:36:28,120 FROM FATTY ACID. 984 00:36:28,120 --> 00:36:29,400 SO WE WANTED TO SEE FIRST OF 985 00:36:29,400 --> 00:36:31,240 ALL, IS IT EVEN POSSIBLE TO HAVE 986 00:36:31,240 --> 00:36:32,920 VESICLES UNDER THOSE CONDITIONS 987 00:36:32,920 --> 00:36:36,920 THAT ARE STABLE? 988 00:36:36,920 --> 00:36:38,240 NOW, FROM HAS BEEN SOME WORK 989 00:36:38,240 --> 00:36:41,720 DONE BY TOM MCCOLLUM AND OTHERS 990 00:36:41,720 --> 00:36:42,840 UNDER HYDROTHERMAL CONDITIONS 991 00:36:42,840 --> 00:36:53,480 USING A PROCESS CALLED 992 00:36:53,480 --> 00:36:55,000 FISCHER-TROPSCH REACTIONS. 993 00:36:55,000 --> 00:36:57,480 THESE ARE FATTY ALCOHOLS AND 994 00:36:57,480 --> 00:37:02,920 FATTY ACIDS WITH A GROUPMENT 995 00:37:02,920 --> 00:37:07,200 AGAIN, 10, 11, 12 CARBONS, SO WE 996 00:37:07,200 --> 00:37:10,120 USE THOSE MIXTURES TO TRY AND 997 00:37:10,120 --> 00:37:14,520 MAKE PROAT CELLS FROM THEM, AND 998 00:37:14,520 --> 00:37:20,720 THIS IS WITH A FRESH DYE TO SHOW 999 00:37:20,720 --> 00:37:23,120 THE VESICLES THEM SELVES. 1000 00:37:23,120 --> 00:37:24,960 YOU CAN SEE WE'RE GETTING 1001 00:37:24,960 --> 00:37:25,920 VESICLES, I'M NOT GOING TO GO 1002 00:37:25,920 --> 00:37:26,840 THROUGH THE DETAILS OF THIS, WE 1003 00:37:26,840 --> 00:37:28,640 CAN COME BACK TO IT BUT TO SAVE 1004 00:37:28,640 --> 00:37:29,760 TIME, I'M GOING TO SKIP OVER IT. 1005 00:37:29,760 --> 00:37:31,800 BUT WE'RE GETTING STABLE 1006 00:37:31,800 --> 00:37:40,440 VESICLES AT PH12, 70 DEGREES 1007 00:37:40,440 --> 00:37:43,000 CENTIGRADE, 50, 10 OF CALCIUM 1008 00:37:43,000 --> 00:37:43,800 CHLORIDE, SO REALLY HARSH 1009 00:37:43,800 --> 00:37:44,120 CONDITIONS. 1010 00:37:44,120 --> 00:37:45,720 THE KIND OF CONDITIONS I WAS 1011 00:37:45,720 --> 00:37:46,680 SAYING THEY'RE SUPPOSED TO FALL 1012 00:37:46,680 --> 00:37:47,080 TO PIECES. 1013 00:37:47,080 --> 00:37:50,160 IF YOU JUST USE A SINGLE FATTY 1014 00:37:50,160 --> 00:37:52,080 ACID, THEY DO, INDEED, FALL TO 1015 00:37:52,080 --> 00:37:52,400 PIECES. 1016 00:37:52,400 --> 00:37:53,640 BUT WHEN WE HAVE THE MORE 1017 00:37:53,640 --> 00:37:56,720 COMPLEX MIXTURES, THEY'RE QUITE 1018 00:37:56,720 --> 00:37:57,000 ROBUST. 1019 00:37:57,000 --> 00:37:59,680 SO THIS WAS REALLY PLEASING. 1020 00:37:59,680 --> 00:38:02,680 WE CAN SEE STABLE PROTO CELLS 1021 00:38:02,680 --> 00:38:03,760 WITHIN THE ENVIRONMENTS. 1022 00:38:03,760 --> 00:38:09,520 EVEN MORE PLEASING, KIND OF THE 1023 00:38:09,520 --> 00:38:10,720 REDUCTION OF CO2. 1024 00:38:10,720 --> 00:38:14,320 THE ENERGY CONVERTING 1025 00:38:14,320 --> 00:38:15,920 HYDROGENASE. 1026 00:38:15,920 --> 00:38:19,520 THEY CONTAIN FOUR FE, AND WE'RE 1027 00:38:19,520 --> 00:38:21,400 WONDERING IN A PREBITE IK 1028 00:38:21,400 --> 00:38:27,320 ENVIRONMENT, I CAN IMAGINE 1029 00:38:27,320 --> 00:38:28,680 MINERALIZED, SO WE SIMPLY TRIED 1030 00:38:28,680 --> 00:38:32,480 MIXING CYSTINE IN WATER, PH9, 1031 00:38:32,480 --> 00:38:34,400 WITH FERRIC CHLORIDE AND SODIUM 1032 00:38:34,400 --> 00:38:36,480 SULFIDE, AND WE GOT THE 1033 00:38:36,480 --> 00:38:41,160 CHARACTERISTIC SHOULDER ON 1034 00:38:41,160 --> 00:38:44,120 U.S. -- ITS 1035 00:38:44,120 --> 00:38:44,680 CONCENTRATION-DEPENDENT, IT 1036 00:38:44,680 --> 00:38:45,880 DEPENDS ON THE CONCENTRATION OF 1037 00:38:45,880 --> 00:38:49,480 THE IRON AND THE SULFUR. 1038 00:38:49,480 --> 00:38:53,360 MOST CONFIRM NIECE ARE 4FE-4S 1039 00:38:53,360 --> 00:38:54,680 CLUSTERS, WE HAVE SOME OTHER 1040 00:38:54,680 --> 00:38:58,800 SPECIES IN THERE. 1041 00:38:58,800 --> 00:39:00,080 VOLTAMMETRY SHOWS THEY ARE NOT 1042 00:39:00,080 --> 00:39:04,040 AS REDUCING AS I'D LIKE THEM TO 1043 00:39:04,040 --> 00:39:05,960 BE. 1044 00:39:05,960 --> 00:39:06,920 MINUS 400 MILLIVOLTS IS 1045 00:39:06,920 --> 00:39:08,520 CERTAINLY NOT VERY REDUCING, NOT 1046 00:39:08,520 --> 00:39:10,680 FLUFF TO REDUCE CO2 BUT THIS IS 1047 00:39:10,680 --> 00:39:12,080 PROBABLY A COMPLEX PEAK AND WE 1048 00:39:12,080 --> 00:39:13,480 NEED TO TRY AND WORK OUT WHAT 1049 00:39:13,480 --> 00:39:14,720 ELSE IS IN THERE. 1050 00:39:14,720 --> 00:39:17,000 WE THINK THERE'S SEVERAL SPECIES 1051 00:39:17,000 --> 00:39:18,120 IN THERE SO WE'RE STILL WORKING 1052 00:39:18,120 --> 00:39:18,400 ON THAT. 1053 00:39:18,400 --> 00:39:20,680 BUT THE KEY THING IS JUST MIXING 1054 00:39:20,680 --> 00:39:23,520 MONOMERS, CYSTINE, IRON, SULFUR 1055 00:39:23,520 --> 00:39:27,720 IN SOLUTION, AND WE'RE GETTING 1056 00:39:27,720 --> 00:39:29,160 4FE-4S CLUSTERS, THE SAME AS 1057 00:39:29,160 --> 00:39:29,760 LIFE. 1058 00:39:29,760 --> 00:39:31,400 I'M JUST GOING TO SHOW YOU TWO 1059 00:39:31,400 --> 00:39:32,400 SLIDES ON SOME SLIGHTLY MORE 1060 00:39:32,400 --> 00:39:33,120 COMPLEX CHEMISTRY THAT WE'VE 1061 00:39:33,120 --> 00:39:33,880 BEEN WORKING ON. 1062 00:39:33,880 --> 00:39:35,000 IF THESE IDEAS ARE RIGHT, THEN 1063 00:39:35,000 --> 00:39:38,000 THE WHOLE OF METABOLIC 1064 00:39:38,000 --> 00:39:38,800 BIOCHEMISTRY OUGHT TO BE 1065 00:39:38,800 --> 00:39:41,320 HAPPENING SPONTANEOUSLY UNDER 1066 00:39:41,320 --> 00:39:41,920 THESE CONDITIONS. 1067 00:39:41,920 --> 00:39:43,880 PEOPLE HAVEN'T DONE MUCH WORK ON 1068 00:39:43,880 --> 00:39:44,120 THIS. 1069 00:39:44,120 --> 00:39:48,280 LOTS OF PEOPLE HAVE WORKED ON 1070 00:39:48,280 --> 00:39:48,880 CYANIDE CHEMISTRY AND SO ON. 1071 00:39:48,880 --> 00:39:55,880 THIS IS FOLLOWING THE PATHWAY OF 1072 00:39:55,880 --> 00:39:56,920 URACIL SYNTHESIS THAT CELLS USE, 1073 00:39:56,920 --> 00:39:58,640 AND THIS IS DOING IT IN THE 1074 00:39:58,640 --> 00:40:00,920 ABSENCE OF ENZYMES, JUST USING 1075 00:40:00,920 --> 00:40:01,840 METAL IONS AS CATALYSTS. 1076 00:40:01,840 --> 00:40:04,920 WE HAVE A BUNCH OF METAL ION 1077 00:40:04,920 --> 00:40:06,360 CATALYSTS, COPPER WORKS QUITE 1078 00:40:06,360 --> 00:40:08,520 WELL, WE'RE ABLE TO GENERATE 1079 00:40:08,520 --> 00:40:09,960 URACIL, WE CAN CHANGE THE 1080 00:40:09,960 --> 00:40:10,720 CONDITION, SWITCHING PH, 1081 00:40:10,720 --> 00:40:11,480 CHANGING PH. 1082 00:40:11,480 --> 00:40:12,720 WE WERE ABLE TO OPTIMIZE THE 1083 00:40:12,720 --> 00:40:14,520 CONDITIONS AND THE CONDITIONS 1084 00:40:14,520 --> 00:40:16,040 THAT WORK BEST TURNED OUT TO BE 1085 00:40:16,040 --> 00:40:17,800 BASICALLY ALKALINE HYDROTHERMAL 1086 00:40:17,800 --> 00:40:19,320 CONDITIONS. 1087 00:40:19,320 --> 00:40:21,720 PH9, 90 DEGREES CENTIGRADE, 100 1088 00:40:21,720 --> 00:40:26,640 BARS PRESSURE, MODERN OCEAN 1089 00:40:26,640 --> 00:40:26,960 SALINITY. 1090 00:40:26,960 --> 00:40:28,880 IT WORKED ABOUT TENFOLD BETTER, 1091 00:40:28,880 --> 00:40:30,480 IN FACT, THAN THE CONDITIONS IN 1092 00:40:30,480 --> 00:40:31,720 WHICH WE STARTED OUT. 1093 00:40:31,720 --> 00:40:33,160 AND THIS ONE I THOUGHT YOU MIGHT 1094 00:40:33,160 --> 00:40:33,800 LIKE. 1095 00:40:33,800 --> 00:40:34,360 THIS IS ATP. 1096 00:40:34,360 --> 00:40:39,480 IF WE START WITH ATP IN 1097 00:40:39,480 --> 00:40:47,880 SOLUTION, AND WE ADD ACETYL 1098 00:40:47,880 --> 00:40:49,080 PHOSPHATE -- THIS IS JUST IN 1099 00:40:49,080 --> 00:40:50,360 WATER, THERE'S NO ENZYMES, NO 1100 00:40:50,360 --> 00:40:54,400 OTHER CATALYSTS THERE, AND WE 1101 00:40:54,400 --> 00:40:55,800 GET 15 TO 20% YIELD. 1102 00:40:55,800 --> 00:40:58,640 THIS IS A PH5.5 TO 6, WORKS LESS 1103 00:40:58,640 --> 00:41:01,000 WELL IN ALKALINE CONDITIONS. 1104 00:41:01,000 --> 00:41:03,520 AND WE TRIED A WHOLE RANGE OF 1105 00:41:03,520 --> 00:41:04,200 DIFFERENT PHOSPHORYLATING AGENTS 1106 00:41:04,200 --> 00:41:08,480 AND REALLY ONLY ACETYL PHOSPHATE 1107 00:41:08,480 --> 00:41:10,120 AND CARBON PHOSPHATE WORKED AT 1108 00:41:10,120 --> 00:41:10,720 ALL. 1109 00:41:10,720 --> 00:41:12,000 THIS WAS THE REALLY BEAUTIFUL 1110 00:41:12,000 --> 00:41:13,040 THING I WANTED TO SHARE WITH 1111 00:41:13,040 --> 00:41:14,440 YOU. 1112 00:41:14,440 --> 00:41:15,720 PHOSPHORYLATING ADP TO ATP, WE 1113 00:41:15,720 --> 00:41:16,840 GET QUITE A NICE PEAK. 1114 00:41:16,840 --> 00:41:17,960 THAT'S WHAT WE'RE SEEING HERE. 1115 00:41:17,960 --> 00:41:21,320 BUT IF WE TRY TO LOOK FOR ITP OR 1116 00:41:21,320 --> 00:41:24,760 GTP OR CTP OR UTP, WE'RE GETTING 1117 00:41:24,760 --> 00:41:26,120 NO MORE THAN THE CONTROL VALUES. 1118 00:41:26,120 --> 00:41:27,920 IN OTHER WORDS, THERE'S 1119 00:41:27,920 --> 00:41:29,720 SOMETHING FAVORED IN WATER ABOUT 1120 00:41:29,720 --> 00:41:30,200 ATP ITSELF. 1121 00:41:30,200 --> 00:41:32,720 THIS IS WHY, IN MY MIND, WHY ATP 1122 00:41:32,720 --> 00:41:36,000 IS THE UNIVERSAL ENERGY CURB 1123 00:41:36,000 --> 00:41:36,320 CURRENCY. 1124 00:41:36,320 --> 00:41:39,760 YOU CAN PHOSPHORYLATE IN WATER 1125 00:41:39,760 --> 00:41:40,800 USING ACETYL PHOSPHATE WHICH IS 1126 00:41:40,800 --> 00:41:43,680 STILL USED IN BACTERIA TODAY AS 1127 00:41:43,680 --> 00:41:47,720 KIND OF THE LINCHPIN BETWEEN -- 1128 00:41:47,720 --> 00:41:48,600 AND PHOSPHATE METABOLISM. 1129 00:41:48,600 --> 00:41:50,280 SO IT'S REALLY -- IT'S BEAUTIFUL 1130 00:41:50,280 --> 00:41:52,000 THAT IT HAPPENED SPONTANEOUSLY 1131 00:41:52,000 --> 00:41:53,920 IN VERY SIMPLE PREBIOTIC 1132 00:41:53,920 --> 00:41:54,240 CONDITIONS. 1133 00:41:54,240 --> 00:41:55,560 SO JUST TO FINISH WITH THE LAST 1134 00:41:55,560 --> 00:41:56,920 THREE OR FOUR MINUTES, IF I MAY, 1135 00:41:56,920 --> 00:41:58,200 I WANT TO JUST TALK ABOUT WHERE 1136 00:41:58,200 --> 00:42:00,520 IT GOES AND HOW THE CODE MIGHT 1137 00:42:00,520 --> 00:42:01,960 EMERGE, THE GENETIC CODE IN 1138 00:42:01,960 --> 00:42:02,840 THESE CONDITIONS. 1139 00:42:02,840 --> 00:42:05,560 HAVE I GOT THREE OR FOUR 1140 00:42:05,560 --> 00:42:06,400 MINUTES, WIN? 1141 00:42:06,400 --> 00:42:08,720 I HOPE I DO. 1142 00:42:08,720 --> 00:42:14,560 SO THIS IS MATHEMATICAL 1143 00:42:14,560 --> 00:42:15,600 MODELING. 1144 00:42:15,600 --> 00:42:16,840 WE'RE CONSIDERING IN A BARRIER 1145 00:42:16,840 --> 00:42:20,840 HERE FIXING CO2, TRAPPED BY 1146 00:42:20,840 --> 00:42:22,120 ORGANICS, AMINO ACIDS LIKE 1147 00:42:22,120 --> 00:42:26,160 CYSTINE, REDUCING CO2 TO AN 1148 00:42:26,160 --> 00:42:32,840 INTERMEDIATE LIKE A METHYL -- 1149 00:42:32,840 --> 00:42:34,920 BRANCHING FROM THERE INTO AMINO 1150 00:42:34,920 --> 00:42:38,320 ACIDS, SUGARS, ACETYL PHOSPHATE 1151 00:42:38,320 --> 00:42:39,160 AND FATTY ACIDS. 1152 00:42:39,160 --> 00:42:41,880 SO THE FATTY ACIDS WOULD 1153 00:42:41,880 --> 00:42:43,200 PARTITION STRAIGHT TO THE 1154 00:42:43,200 --> 00:42:44,240 MEMBRANE, AMINO ACIDS CAN 1155 00:42:44,240 --> 00:42:46,440 INTERACT WITH THE IRON SULFUR 1156 00:42:46,440 --> 00:42:48,920 INCLUDES TURS AND DRIVE CO2 1157 00:42:48,920 --> 00:42:49,720 FIXATION AND SO ON. 1158 00:42:49,720 --> 00:42:51,240 WHAT HAPPENS IF WE ALLOW THIS 1159 00:42:51,240 --> 00:42:52,960 CHEMISTRY TO MOVE FORWARD RIGHT 1160 00:42:52,960 --> 00:42:55,680 THE WAY THROUGH TO NUCLEOTIDES? 1161 00:42:55,680 --> 00:42:57,200 AS I'VE JUN SHOWN YOU, IT SEEMS 1162 00:42:57,200 --> 00:42:57,840 TO BE POSSIBLE. 1163 00:42:57,840 --> 00:42:59,840 THEN WE ASSUME THERE'S POSITIVE 1164 00:42:59,840 --> 00:43:01,960 FEEDBACK, WE CAN ASSUME POSITIVE 1165 00:43:01,960 --> 00:43:02,840 FEEDBACK ON CO2 FIXATION. 1166 00:43:02,840 --> 00:43:07,160 THIS IS WHAT WE SEE WITH 1167 00:43:07,160 --> 00:43:09,520 FOLATES, FOR EXAMPLE, 1168 00:43:09,520 --> 00:43:11,840 METHANOGENS, THEY'RE INVOLVED IN 1169 00:43:11,840 --> 00:43:12,560 CO2 FIXATIONS. 1170 00:43:12,560 --> 00:43:13,880 SO WE CAN ASSUME POSITIVE 1171 00:43:13,880 --> 00:43:15,520 FEEDBACK THERE AND ASK WHAT 1172 00:43:15,520 --> 00:43:16,920 HAPPENS, OR WE CAN ASSUME ALL 1173 00:43:16,920 --> 00:43:18,360 OTHER KINDS OF POSITIVE 1174 00:43:18,360 --> 00:43:19,320 FEEDBACKS ON ANY OF THESE 1175 00:43:19,320 --> 00:43:20,880 PATHWAYS, SEE WHAT HAPPENS THEN, 1176 00:43:20,880 --> 00:43:23,440 OR WE CAN ASSUME AUTO CATALYSIS 1177 00:43:23,440 --> 00:43:25,720 JUST FAVORING NUCLEOTIDE 1178 00:43:25,720 --> 00:43:26,000 SYNTHESIS. 1179 00:43:26,000 --> 00:43:27,320 WHAT WE FIND, AND I'M NOT GOING 1180 00:43:27,320 --> 00:43:28,600 TO GO THROUGH ALL THE RESULTS 1181 00:43:28,600 --> 00:43:29,960 HERE, BUT WHAT WE'RE FINDING, 1182 00:43:29,960 --> 00:43:33,200 REALLY, IS THAT YES, IT CAN 1183 00:43:33,200 --> 00:43:33,840 DRIVE PROTOCELL GROWTH UNDER 1184 00:43:33,840 --> 00:43:34,920 SOME SETS OF CONDITIONS IF WE 1185 00:43:34,920 --> 00:43:36,400 HAVE THIS SITUATION WHERE IT'S 1186 00:43:36,400 --> 00:43:42,520 JUST, FOR EXAMPLE, FARING FAIR FAVORING 1187 00:43:42,520 --> 00:43:45,840 AMINO ACID -- THAT FOSTERS FLUX 1188 00:43:45,840 --> 00:43:48,000 DOWN ONE PATHWAY AT THE EXPENSE 1189 00:43:48,000 --> 00:43:50,320 OF THE OTHERS AND COLLAPSES 1190 00:43:50,320 --> 00:43:50,960 PROTOCELL GROWTH. 1191 00:43:50,960 --> 00:43:52,520 SO WE WANT GENERAL CATALYSIS, 1192 00:43:52,520 --> 00:43:55,800 THE KIND OF THINGS THAT KNEW 1193 00:43:55,800 --> 00:43:57,360 NUCLEOTIDE COFACTORS ARE IN 1194 00:43:57,360 --> 00:43:59,040 TODAY. 1195 00:43:59,040 --> 00:44:03,840 WE HOPED WE'D BE -- SOME SET OF 1196 00:44:03,840 --> 00:44:05,800 CONDITIONS WOULD ALLOW US TO 1197 00:44:05,800 --> 00:44:08,160 ACCUMULATE AND THEN THEY'D BE 1198 00:44:08,160 --> 00:44:09,520 MORE LIKELY POLYMERIZE. 1199 00:44:09,520 --> 00:44:10,920 BUT THE ASSUMPTION THAT THEY'RE 1200 00:44:10,920 --> 00:44:11,920 CATALYSTS MEANS ACTUALLY THEY 1201 00:44:11,920 --> 00:44:12,960 NEVER DO THAT BECAUSE THEY 1202 00:44:12,960 --> 00:44:15,080 CATALYZE THE GROWTH OF CELLS SO 1203 00:44:15,080 --> 00:44:16,360 THEY KEEP DIVIDING AND DILUTING 1204 00:44:16,360 --> 00:44:17,920 THE CONTENTS AT EVERY CELL 1205 00:44:17,920 --> 00:44:18,920 DIVISION. 1206 00:44:18,920 --> 00:44:22,080 SO IN PRINCIPLE, THIS CAN 1207 00:44:22,080 --> 00:44:22,320 HAPPEN. 1208 00:44:22,320 --> 00:44:26,560 HOW COULD GENES EMERGE IN THIS 1209 00:44:26,560 --> 00:44:26,960 ENVIRONMENT? 1210 00:44:26,960 --> 00:44:28,920 THIS IS JUST WHAT I'D LIKE TO 1211 00:44:28,920 --> 00:44:31,120 LEAVE YOU WITH, WE CAN COME BACK 1212 00:44:31,120 --> 00:44:32,320 AND ASK QUESTIONS LATER ON. 1213 00:44:32,320 --> 00:44:36,080 IN ARE THERE ARE PATTERNS IN THE 1214 00:44:36,080 --> 00:44:37,360 GENETIC CODE, I'M GOING TO POINT 1215 00:44:37,360 --> 00:44:38,360 TO THREE VERY QUICKLY. 1216 00:44:38,360 --> 00:44:41,320 THIS IS A QUICK SCHEME OF AUTO 1217 00:44:41,320 --> 00:44:41,920 TROPHIC METABOLISM, WHAT I 1218 00:44:41,920 --> 00:44:43,120 SHOWED YOU EARLIER ON. 1219 00:44:43,120 --> 00:44:48,360 IN GREY, THIS IS WHERE THE FIRST 1220 00:44:48,360 --> 00:44:50,080 SPACE OF THE CODON IS A G, AND 1221 00:44:50,080 --> 00:44:50,960 IN YELLOW, THIS IS WHERE THE 1222 00:44:50,960 --> 00:44:52,680 FIRST BASE OF THE CODON IS AN A. 1223 00:44:52,680 --> 00:44:56,400 SO THE FIRST STEPS OF PURINES, 1224 00:44:56,400 --> 00:44:59,000 ENCODED BY PURINES. 1225 00:44:59,000 --> 00:45:03,400 THEN WITH GREEN, THIS IS URACIL 1226 00:45:03,400 --> 00:45:05,920 AT THE FIRST BASE AND WITH BLUE, 1227 00:45:05,920 --> 00:45:07,200 IT'S A C FOR THAT FIRST BASE. 1228 00:45:07,200 --> 00:45:09,360 SO WE SEE THAT THERE IS -- THIS 1229 00:45:09,360 --> 00:45:11,000 IS THE MINIMUM NUMBER OF STEPS 1230 00:45:11,000 --> 00:45:12,720 FROM CO2 FIXATION, THERE'S A 1231 00:45:12,720 --> 00:45:14,120 VERY CLEAR RELATIONSHIP OF THE 1232 00:45:14,120 --> 00:45:15,280 ORDER OF THE BASES. 1233 00:45:15,280 --> 00:45:17,280 IT SEEMS TO SUGGEST THE PURINES 1234 00:45:17,280 --> 00:45:19,320 CAME FIRST, PURINES CAME BEFORE 1235 00:45:19,320 --> 00:45:21,720 PRIM DEANS, AND ESPECIALLY GWAS 1236 00:45:21,720 --> 00:45:21,920 EARLY. 1237 00:45:21,920 --> 00:45:25,640 THIS IS THE SECOND BASE IN THE 1238 00:45:25,640 --> 00:45:27,320 CODON, AND IF WE HAVE A G OR AN 1239 00:45:27,320 --> 00:45:29,000 A AT THE FIRST POSITION, WE SEE 1240 00:45:29,000 --> 00:45:30,320 QUITE A STRONG RELATIONSHIP. 1241 00:45:30,320 --> 00:45:35,000 THIS IS FROM 43 DIFFERENT 1242 00:45:35,000 --> 00:45:42,440 INDICES OF HYDROPHOBICITY OF THE 1243 00:45:42,440 --> 00:45:43,840 AMINO ACID AND THE BASE OF THAT 1244 00:45:43,840 --> 00:45:44,280 SECOND POSITION. 1245 00:45:44,280 --> 00:45:48,000 IT'S NOT NEARLY SO STRONG IF 1246 00:45:48,000 --> 00:45:50,400 THERE'S A -- THERE SEEMS TO BE 1247 00:45:50,400 --> 00:45:52,600 BOTH A TIME FACTOR AND A 1248 00:45:52,600 --> 00:45:53,280 BIOPHYSICAL INTERACTION GOING ON 1249 00:45:53,280 --> 00:45:54,240 HERE, AND THIS IS THE FINAL 1250 00:45:54,240 --> 00:45:55,840 THING I'D LIKE TO LEAVE YOU 1251 00:45:55,840 --> 00:45:59,800 WITH, THERE'S ALSO PATTERNS AT 1252 00:45:59,800 --> 00:46:00,720 THE THIRD POSITION IN THE CODE 1253 00:46:00,720 --> 00:46:03,840 WHICH WE THINK OTHER PEOPLE 1254 00:46:03,840 --> 00:46:06,280 HAVEN'T SPOTTED BEFORE 1255 00:46:06,280 --> 00:46:07,560 SURPRISINGLY, SO THIS IS AN 1256 00:46:07,560 --> 00:46:08,720 INVERTED CODON TABLE WHERE 1257 00:46:08,720 --> 00:46:17,520 POSITION THREE, WE EITHER HAVE A 1258 00:46:17,520 --> 00:46:19,600 A -- IF WE HAVE A G AND AN A AT 1259 00:46:19,600 --> 00:46:21,360 THE FIRST AND SECOND POSITIONS 1260 00:46:21,360 --> 00:46:23,480 AND A G AND AN A AT THE FIRST 1261 00:46:23,480 --> 00:46:24,920 AND SECOND POSITIONS, IT MATTERS 1262 00:46:24,920 --> 00:46:29,840 WHETHER THERE'S A PURINE OR 1263 00:46:29,840 --> 00:46:30,680 PYRIMIDINE AT THE THIRD 1264 00:46:30,680 --> 00:46:30,920 POSITION. 1265 00:46:30,920 --> 00:46:35,960 IF WE CAN PREDICT PURINE, -- 1266 00:46:35,960 --> 00:46:37,360 THAT DIFFERENCE DEPENDS ON THE 1267 00:46:37,360 --> 00:46:39,080 SIZE OF THOSE AMINO ACIDS. 1268 00:46:39,080 --> 00:46:44,920 SO AGAIN, THERE'S A PHYSICAL 1269 00:46:44,920 --> 00:46:45,600 RELATIONSHIP BETWEEN THE SIZE 1270 00:46:45,600 --> 00:46:48,400 AND THE HYDRO -- PROBABLY A TIME 1271 00:46:48,400 --> 00:46:48,640 FACTOR. 1272 00:46:48,640 --> 00:46:50,200 WE CAN'T UNDERSTAND THE DETAILS 1273 00:46:50,200 --> 00:46:51,720 OF THIS YET, BUT ALL I NEED TO 1274 00:46:51,720 --> 00:46:54,040 DO IS POSIT THAT THERE ARE 1275 00:46:54,040 --> 00:46:55,240 NON-RANDOM RELATIONSHIPS BETWEEN 1276 00:46:55,240 --> 00:46:58,560 THE AMINO ACIDS AND RANDOM RNA 1277 00:46:58,560 --> 00:46:58,960 SEQUENCES. 1278 00:46:58,960 --> 00:47:00,800 SO IF WE HAVE BIOPHYSICAL 1279 00:47:00,800 --> 00:47:03,720 INTERACTIONS BETWEEN AMINO ACIDS 1280 00:47:03,720 --> 00:47:05,440 AND RANDOM RNA SEQUENCES, IF 1281 00:47:05,440 --> 00:47:07,640 WE'RE INTRODUCING RAN DONE RNA 1282 00:47:07,640 --> 00:47:10,320 POLYMERS INTO THESE PROTOCELLS, 1283 00:47:10,320 --> 00:47:11,920 THERE'S A PURELY RANDOM SEQUENCE 1284 00:47:11,920 --> 00:47:15,200 BUT WE HAVE A NON-RANDOM PEPTIDE 1285 00:47:15,200 --> 00:47:17,320 AND IN THE CONTEXT OF GROWING 1286 00:47:17,320 --> 00:47:18,000 PROTOCELLS, THAT HAS FUNCTION. 1287 00:47:18,000 --> 00:47:20,520 IF IT'S A HYDROPHOBIC PEPTIDE, 1288 00:47:20,520 --> 00:47:22,080 IT'S LIKELY TO GO TO THE 1289 00:47:22,080 --> 00:47:24,080 MEMBRANE, IT MAY BE INVOLVED IN 1290 00:47:24,080 --> 00:47:24,480 CO2 FIXATION. 1291 00:47:24,480 --> 00:47:28,280 IF IT'S A HYDROPHILIC PEPTIDE, 1292 00:47:28,280 --> 00:47:31,640 IT'S LIKELY TO COLLATE IONS LIKE 1293 00:47:31,640 --> 00:47:31,920 MAGNESIUM. 1294 00:47:31,920 --> 00:47:33,280 ASPARTATE WOULD INTERACT 1295 00:47:33,280 --> 00:47:40,600 DIRECTLY WITH MAGNESIUM. 1296 00:47:40,600 --> 00:47:42,120 IT'S JUST BIOPHYSICS. 1297 00:47:42,120 --> 00:47:44,080 ALL KINDS OF MIXED PEPTIDES ARE 1298 00:47:44,080 --> 00:47:45,960 LIKELY TO BIND NUCLEOTIDE 1299 00:47:45,960 --> 00:47:47,080 COFACTORS AND PROMOTE 1300 00:47:47,080 --> 00:47:47,520 PROTOMETABOLISM. 1301 00:47:47,520 --> 00:47:49,760 WE CAN EASILY SEE HOW FUNCTIONS 1302 00:47:49,760 --> 00:47:52,000 CAN EMERGE IN THE GROWING 1303 00:47:52,000 --> 00:47:54,320 PROTOCELL SYSTEM JUST SIMPLY 1304 00:47:54,320 --> 00:47:54,720 THROUGH BIOPHYSICAL 1305 00:47:54,720 --> 00:47:55,080 INTERACTIONS. 1306 00:47:55,080 --> 00:47:57,040 AND THAT MEANS THAT WE HAVE 1307 00:47:57,040 --> 00:47:57,920 SEQUENCE-DEPENDENT FUNCTIONS AND 1308 00:47:57,920 --> 00:47:59,520 THEY WILL BE INHERITED SO LONG 1309 00:47:59,520 --> 00:48:02,280 AS THAT SEQUENCE IS COPIED. 1310 00:48:02,280 --> 00:48:03,200 SO INFORMATION COMES INTO 1311 00:48:03,200 --> 00:48:04,920 BIOLOGY RIGHT FROM THE VERY 1312 00:48:04,920 --> 00:48:08,680 BEGINNING IN THIS PROTOCELL 1313 00:48:08,680 --> 00:48:08,920 CONTEXT. 1314 00:48:08,920 --> 00:48:10,400 AND I DON'T THINK IT DOES IN ANY 1315 00:48:10,400 --> 00:48:10,760 OTHER CONTEXT. 1316 00:48:10,760 --> 00:48:11,840 SO I'M GOING TO LEAVE WITH YOU 1317 00:48:11,840 --> 00:48:13,760 THAT, AND I HAVE TO SAY THANK 1318 00:48:13,760 --> 00:48:15,760 YOU ENORMOUSLY TO MY GROUP, 1319 00:48:15,760 --> 00:48:16,880 BECAUSE THEY'RE BRAVE PEOPLE TO 1320 00:48:16,880 --> 00:48:18,240 RISK THEIR CAREERS COMING TO 1321 00:48:18,240 --> 00:48:19,760 WORK WITH ME ON QUESTIONS LIKE 1322 00:48:19,760 --> 00:48:20,800 THE ORIGIN OF LIFE WHERE THERE'S 1323 00:48:20,800 --> 00:48:21,880 NO GUARANTEE THEY'RE GOING TO 1324 00:48:21,880 --> 00:48:23,440 FIND ANYTHING AT ALL, SO I THANK 1325 00:48:23,440 --> 00:48:26,000 THEM AND I THANK YOU, AND I'M 1326 00:48:26,000 --> 00:48:29,920 GOING TO PASS OVER TO JENNIFER. 1327 00:48:29,920 --> 00:48:30,880 I THINK QUESTIONS COME LATER. 1328 00:48:30,880 --> 00:48:36,280 THANK YOU. 1329 00:48:36,280 --> 00:48:37,600 I HOPE I DIDN'T OVERRUN TOO 1330 00:48:37,600 --> 00:48:37,960 MUCH. 1331 00:48:37,960 --> 00:48:39,360 >> PLEASE CONTINUE TO REMEMBER 1332 00:48:39,360 --> 00:48:40,880 TO SUBMIT YOUR QUESTIONS, AND WE 1333 00:48:40,880 --> 00:48:41,720 WILL HAVE QUESTION AND ANSWER AT 1334 00:48:41,720 --> 00:48:45,280 THE END OF JENNIFER'S TALK. 1335 00:48:45,280 --> 00:48:46,760 SO NOW WE'RE GOING TO TURN TO 1336 00:48:46,760 --> 00:48:50,320 THE EMERGENCE OF THE EU 1337 00:48:50,320 --> 00:48:51,320 KARYOCITE. 1338 00:48:51,320 --> 00:48:51,760 JENNIFER? 1339 00:48:51,760 --> 00:48:55,520 >>IT'S QUITE AN HONOR TO 1340 00:48:55,520 --> 00:48:59,920 FOLLOW NICK LANE, WHOSE WORK I 1341 00:48:59,920 --> 00:49:02,080 HAVE REALLY BEEN IN AWE. 1342 00:49:02,080 --> 00:49:04,800 A LOT OF THE IDEAS THAT I'M 1343 00:49:04,800 --> 00:49:05,840 GOING TO TALK ABOUT TODAY 1344 00:49:05,840 --> 00:49:08,280 ACTUALLY COME OUT OF HIS BOOK, 1345 00:49:08,280 --> 00:49:09,840 "THE VITAL QUESTION," WHICH 1346 00:49:09,840 --> 00:49:12,040 REALLY TRANSFORM MY THINKING 1347 00:49:12,040 --> 00:49:13,920 ABOUT EUKARYOTIC CELLS, AND THE 1348 00:49:13,920 --> 00:49:16,840 WAY THAT THEY'VE ORIGINATED. 1349 00:49:16,840 --> 00:49:20,160 SO THIS IS GOING TO BE A 1350 00:49:20,160 --> 00:49:20,880 PERSPECTIVE. 1351 00:49:20,880 --> 00:49:22,240 BASICALLY ALL THE IDEAS THAT I'M 1352 00:49:22,240 --> 00:49:24,000 GOING TO BE TALKING ABOUT ARE 1353 00:49:24,000 --> 00:49:25,080 ONES THAT WE REALLY NEED FURTHER 1354 00:49:25,080 --> 00:49:27,000 TESTING, BUT I AM GOING TO TAKE 1355 00:49:27,000 --> 00:49:29,680 THE HINT FROM WIN TO JUST THROW 1356 00:49:29,680 --> 00:49:33,840 OUT SOME OF THESE IDEAS JUST TO 1357 00:49:33,840 --> 00:49:40,280 START A CONVERSATION. 1358 00:49:40,280 --> 00:49:41,400 SO I THINK ONE OF THE THINGS 1359 00:49:41,400 --> 00:49:42,680 THAT REALLY FORCES YOU TO THINK 1360 00:49:42,680 --> 00:49:45,200 HARD ABOUT THE ORIGIN OF 1361 00:49:45,200 --> 00:49:47,840 EUKARYOTIC CELL IS TO FIRST LOOK 1362 00:49:47,840 --> 00:49:51,320 OUT AT A PLANET THAT HAS NO 1363 00:49:51,320 --> 00:49:54,360 LIFE, LIKE MARS, AND THEN MOVE 1364 00:49:54,360 --> 00:49:55,720 INTO A PLANET LIKE EARTH THAT IS 1365 00:49:55,720 --> 00:50:00,640 FULL OF LIFE. 1366 00:50:00,640 --> 00:50:03,120 WHEN YOU LOOK OUT AT THIS 1367 00:50:03,120 --> 00:50:03,800 PLANETARY LANDSCAPE, WHAT YOU'RE 1368 00:50:03,800 --> 00:50:05,280 SEEING IS HIDDEN UNDERNEATH 1369 00:50:05,280 --> 00:50:07,280 PLENTY OF PROKARYOTIC LIFE, BUT 1370 00:50:07,280 --> 00:50:09,520 ALSO AN INCREDIBLY EMERGENT 1371 00:50:09,520 --> 00:50:10,640 EUKARYOTIC SYSTEM. 1372 00:50:10,640 --> 00:50:11,880 THAT'S WHAT WE'RE LOOKING AT 1373 00:50:11,880 --> 00:50:18,160 HERE, AND THAT'S WHAT WE ALL ARE 1374 00:50:18,160 --> 00:50:20,120 OPERATING WITHIN AS PHYSICAL BIG 1375 00:50:20,120 --> 00:50:20,960 HUMAN,. 1376 00:50:20,960 --> 00:50:22,200 NOW 1377 00:50:22,200 --> 00:50:22,960 HUMAN BEINGS. 1378 00:50:22,960 --> 00:50:24,480 NOW THE EVOLUTION OF -- THERE'S 1379 00:50:24,480 --> 00:50:26,680 A LOT OF THINKING ABOUT NOT ONLY 1380 00:50:26,680 --> 00:50:29,080 THE TREE OF LIFE, YOU KNOW, HOW 1381 00:50:29,080 --> 00:50:34,560 WE MOVE INTO THIS LARGE 1382 00:50:34,560 --> 00:50:43,240 EUKARYOTIC WORLD, BUT I THINK 1383 00:50:43,240 --> 00:50:46,240 ONE OF THE THINGS THAT IS REALLY 1384 00:50:46,240 --> 00:50:48,720 SORT OF A STARTING QUESTION IS 1385 00:50:48,720 --> 00:50:51,040 FIRST WHY DID IT TAKE 2 BILLION 1386 00:50:51,040 --> 00:50:54,480 YEARS BEFORE WE REACHED THIS 1387 00:50:54,480 --> 00:50:56,640 SITE OF THE LAST EUKARYOTIC 1388 00:50:56,640 --> 00:51:01,240 COMMON AN SES ANCESTOR, AND THEN WHAT 1389 00:51:01,240 --> 00:51:03,680 ARE THE CHANGES THAT HAPPENED 1390 00:51:03,680 --> 00:51:06,480 OVER THE NEXT 2 BILLION YEARS TO 1391 00:51:06,480 --> 00:51:08,880 CREATE THIS INCREDIBLE DIVERSITY 1392 00:51:08,880 --> 00:51:10,840 AND STRUCTURE THAT WE SEE THAT'S 1393 00:51:10,840 --> 00:51:12,360 CHARACTERISTIC OF EUKARYOTIC 1394 00:51:12,360 --> 00:51:12,560 CELLS. 1395 00:51:12,560 --> 00:51:17,600 AND I THINK ONE OF THE CLEAR 1396 00:51:17,600 --> 00:51:20,200 POINTS THAT NICK'S PRESENTATION 1397 00:51:20,200 --> 00:51:25,000 REALLY MADE CLEAR IS THAT IN THE 1398 00:51:25,000 --> 00:51:26,760 PROKARYOTIC KINGDOM, IT'S REALLY 1399 00:51:26,760 --> 00:51:28,720 METABOLISM THAT IS AT THE HEART. 1400 00:51:28,720 --> 00:51:32,240 BASICALLY LIFE WAS GETTING HOLD 1401 00:51:32,240 --> 00:51:37,720 OF A RICH METABOLISM THAT 1402 00:51:37,720 --> 00:51:39,080 ULTIMATELY LED TO A NEW 1403 00:51:39,080 --> 00:51:39,720 INVENTION. 1404 00:51:39,720 --> 00:51:43,480 THIS INVENTION IS THE EUKARYOTIC 1405 00:51:43,480 --> 00:51:43,840 CELL. 1406 00:51:43,840 --> 00:51:44,680 WHICH THEN MOVED INTO A 1407 00:51:44,680 --> 00:51:46,160 DIFFERENT TYPE OF DIMENSION IN 1408 00:51:46,160 --> 00:51:51,520 TERMS OF EXPLORING SPACE ON A 1409 00:51:51,520 --> 00:51:54,000 MANET, AND 1410 00:51:54,000 --> 00:51:55,880 PLANET, AND THAT IS STRUCTURAL 1411 00:51:55,880 --> 00:51:57,120 DIVERSITY, WHERE WE HAVE 1412 00:51:57,120 --> 00:52:00,560 ANIMALS, PLANT, FUNGI, SEA WE'D 1413 00:52:00,560 --> 00:52:01,800 AND AMOEBA. 1414 00:52:01,800 --> 00:52:03,080 ONE OF THE THINGS THAT HAS 1415 00:52:03,080 --> 00:52:07,320 ALWAYS EXCITED ME IS THE 1416 00:52:07,320 --> 00:52:10,680 COMPLEXITY OF THEIR INTERNAL 1417 00:52:10,680 --> 00:52:11,160 COMPARTMENTALIZATION. 1418 00:52:11,160 --> 00:52:13,440 WHAT YOU'RE LOOKING AT IS AN EM 1419 00:52:13,440 --> 00:52:15,520 SLICE OF A MOUSE FIBROBLAST, AND 1420 00:52:15,520 --> 00:52:17,560 YOU CAN SEE THE HUGE DIVERSITY 1421 00:52:17,560 --> 00:52:19,280 OF SUBCELLULAR STRUCTURES OR 1422 00:52:19,280 --> 00:52:21,680 COMPARTMENTS THAT COMPRISE THIS 1423 00:52:21,680 --> 00:52:26,080 CELL SYSTEM. 1424 00:52:26,080 --> 00:52:27,880 WHAT'S QUITE AMAZING ABOUT 1425 00:52:27,880 --> 00:52:29,880 EUKARYOTIC CELLS IS THAT EVEN 1426 00:52:29,880 --> 00:52:32,280 SIMPLE, MORE SORT OF COMPACT 1427 00:52:32,280 --> 00:52:34,320 VERSIONS OF EUKARYOTIC CELLS, 1428 00:52:34,320 --> 00:52:38,080 INCLUDING THIS PARASITE, 1429 00:52:38,080 --> 00:52:40,080 TOXOPLASMA GONDII, HAS THE EXACT 1430 00:52:40,080 --> 00:52:42,320 SAME SET OF NINE ORGANELLES THAT 1431 00:52:42,320 --> 00:52:44,840 CHARACTERIZE THIS MUCH LARGER 1432 00:52:44,840 --> 00:52:45,120 FIBROBLAST. 1433 00:52:45,120 --> 00:52:48,480 SO BASICALLY THERE'S A 1434 00:52:48,480 --> 00:52:50,880 CONSERVATION IN THE 1435 00:52:50,880 --> 00:52:52,440 COMPARTMENTIZATION OF THESE 1436 00:52:52,440 --> 00:52:54,920 EUKARYOTIC CELLS, WHICH I THINK 1437 00:52:54,920 --> 00:52:57,840 DESERVES THINKING ABOUT WHEN WE 1438 00:52:57,840 --> 00:52:58,760 START COMING UP WITH MODELS FOR 1439 00:52:58,760 --> 00:53:04,280 HOW THE EUKARYOTIC CELL ITSELF 1440 00:53:04,280 --> 00:53:06,160 EVOLVED. 1441 00:53:06,160 --> 00:53:08,080 BASICALLY ALL EUKARYOTIC CELLS 1442 00:53:08,080 --> 00:53:09,680 HAVE CONSERVED MEMBRANE-BOUND 1443 00:53:09,680 --> 00:53:11,000 STRUCTURES THAT ARE PERFORMING 1444 00:53:11,000 --> 00:53:15,080 VERY SPECIFIC TASKS, WHICH RANGE 1445 00:53:15,080 --> 00:53:16,480 FROM ENERGY METABOLISM IN THE 1446 00:53:16,480 --> 00:53:21,360 CASE OF MITOCHONDRIA TO DELIVERY 1447 00:53:21,360 --> 00:53:22,040 OF MACROMOLECULES TO THE OUTSIDE 1448 00:53:22,040 --> 00:53:24,440 OF THE CELL TO DIFFERENT OTHER 1449 00:53:24,440 --> 00:53:25,960 SUBCELL COMPARTMENTS AND ALSO A 1450 00:53:25,960 --> 00:53:28,480 PROCESS OF ENDO CYTOSIS AND 1451 00:53:28,480 --> 00:53:31,640 UPTAKE OF MACRO MOLECULES. 1452 00:53:31,640 --> 00:53:33,960 NOW THERE ARE SEVERAL MODELS FOR 1453 00:53:33,960 --> 00:53:35,560 THE ORIGIN OF EUKARYOTIC CELLS, 1454 00:53:35,560 --> 00:53:37,000 BUT TWO OF THOSE, I'M GOING TO 1455 00:53:37,000 --> 00:53:40,560 FOCUS ON TODAY, AND PERHAPS THE 1456 00:53:40,560 --> 00:53:42,280 MOST WIDELY RECOGNIZED MODEL FOR 1457 00:53:42,280 --> 00:53:45,000 THE ORIGIN OF EUKARYOTES IS WHAT 1458 00:53:45,000 --> 00:53:48,680 WE CALL STEP DID WISE EVOLUTION. 1459 00:53:48,680 --> 00:53:50,400 BASICALLY THE IDEA BEHIND THIS 1460 00:53:50,400 --> 00:53:56,360 MODEL IS THAT PROKARYOTES 1461 00:53:56,360 --> 00:53:58,040 BASICALLY GOT TIRED OF BEING 1462 00:53:58,040 --> 00:54:00,280 SIMPLE AND STARTED ELABORATING 1463 00:54:00,280 --> 00:54:04,280 ITS INTERNAL MEMBRANES 1464 00:54:04,280 --> 00:54:07,200 POTENTIALLY BY INVAGINATION OF 1465 00:54:07,200 --> 00:54:08,680 THE MEMBRANE, BUT BASICALLY THAT 1466 00:54:08,680 --> 00:54:12,400 LED TO WHAT WE CALL A 1467 00:54:12,400 --> 00:54:13,640 PROTOEUKARYOTE WHICH ALREADY HAD 1468 00:54:13,640 --> 00:54:15,680 A SIMPLIFIED SET OF ENDO 1469 00:54:15,680 --> 00:54:16,480 MEMBRANES, ALREADY HAD SORT OF 1470 00:54:16,480 --> 00:54:19,480 PERHAPS A PRIMITIVE NUCLEUS, AND 1471 00:54:19,480 --> 00:54:21,560 BASICALLY ALL THAT WAS NEEDED IS 1472 00:54:21,560 --> 00:54:25,680 TO CREATE A MORE MODERN 1473 00:54:25,680 --> 00:54:28,240 EUKARYOTIC CELL WAS THE 1474 00:54:28,240 --> 00:54:33,000 INTERNALIZATION OR UPTAKE OF 1475 00:54:33,000 --> 00:54:35,480 BACTERIA, WHICH WOULD CREATE A 1476 00:54:35,480 --> 00:54:37,880 MITOCHONDRIA, WHICH ITSELF COULD 1477 00:54:37,880 --> 00:54:39,400 BECOME AN INTEGRATED PART OF 1478 00:54:39,400 --> 00:54:40,480 THAT EUKARYOTIC CELL BY 1479 00:54:40,480 --> 00:54:42,600 TRANSFERRING PART OF ITS DNA 1480 00:54:42,600 --> 00:54:45,240 INTO THE NUCLEUS OF THIS 1481 00:54:45,240 --> 00:54:46,200 PROTOEUKARYOTIC HOST. 1482 00:54:46,200 --> 00:54:47,720 AND ULTIMATELY, YOU WOULD THEN 1483 00:54:47,720 --> 00:54:51,320 GET THE COMPLEX EUKARYOTIC CELL. 1484 00:54:51,320 --> 00:54:53,640 NOW THE PROBLEM WITH THIS 1485 00:54:53,640 --> 00:54:55,920 STEP-WISE EVOLUTIONARY MODEL IS 1486 00:54:55,920 --> 00:54:58,200 THAT THERE ARE NO SURVIVING 1487 00:54:58,200 --> 00:55:03,480 PROTO EUKARYOTES TODAY THAT SHOW 1488 00:55:03,480 --> 00:55:06,160 ANY EVIDENCE FOR THIS PATHWAY. 1489 00:55:06,160 --> 00:55:08,800 WE CAN'T FIND PROTO EUKARYOTES, 1490 00:55:08,800 --> 00:55:11,880 WE CAN'T FIND EU CARE YOTS EUKARYOTES THA T 1491 00:55:11,880 --> 00:55:12,960 HAVE A SUBSET OF THE 1492 00:55:12,960 --> 00:55:14,080 COMPARTMENTS THAT I JUST SHOWED 1493 00:55:14,080 --> 00:55:18,680 YOU. 1494 00:55:18,680 --> 00:55:20,480 OR PROTOEUKARYOTES THAT LACK 1495 00:55:20,480 --> 00:55:22,600 MITOCHONDRIA OR SOME HEREDITARY 1496 00:55:22,600 --> 00:55:25,160 VESTIGE OF THE MITOCHONDRIA. 1497 00:55:25,160 --> 00:55:26,960 BASICALLY ALL EUKARYOTIC CELLS 1498 00:55:26,960 --> 00:55:30,960 NOW HAVE VERY SIMILAR IDENTICAL 1499 00:55:30,960 --> 00:55:36,000 SETS OF ORGANELLES. 1500 00:55:36,000 --> 00:55:40,560 WE ALSO KNOW THAT THESE 1501 00:55:40,560 --> 00:55:41,480 ORGANELLES, THESE INTERNAL OR 1502 00:55:41,480 --> 00:55:43,480 NELS OF THESE EUKARYOTES ARE ALL 1503 00:55:43,480 --> 00:55:45,320 DOING VERY SMALLER THINGS IN ALL 1504 00:55:45,320 --> 00:55:46,240 EUKARYOTES. 1505 00:55:46,240 --> 00:55:49,240 SO BASICALLY THESE ARE ARGUMENTS 1506 00:55:49,240 --> 00:55:51,800 THAT DOESN'T RULE OUT THE 1507 00:55:51,800 --> 00:55:52,880 STEPWISE EVOLUTION BUT MAKES YOU 1508 00:55:52,880 --> 00:55:54,480 START WONDERING WHETHER SOME 1509 00:55:54,480 --> 00:55:58,120 OTHER MODEL MIGHT FIT THE BILL 1510 00:55:58,120 --> 00:56:00,760 MORE SPECIFICALLY. 1511 00:56:00,760 --> 00:56:02,920 THAT OTHER MODEL THAT I WANT TO 1512 00:56:02,920 --> 00:56:07,320 TALK ABOUT TODAY, AND REALLY 1513 00:56:07,320 --> 00:56:14,720 BUILDS ON THE REALLY FASCINATING 1514 00:56:14,720 --> 00:56:16,680 IDEAS THAT NICK TALKED ABOUT 1515 00:56:16,680 --> 00:56:19,440 TODAY IS A TYPE OF METABOLIC 1516 00:56:19,440 --> 00:56:19,680 SYMBIOSIS. 1517 00:56:19,680 --> 00:56:22,760 AND IN THIS MODEL BASICALLY IS 1518 00:56:22,760 --> 00:56:27,680 THAT A EUKARYOTIC CELL IS 1519 00:56:27,680 --> 00:56:30,520 FUNDAMENTALLY A SYMBIOTIC 1520 00:56:30,520 --> 00:56:32,280 RELATIONSHIP BETWEEN THE TWO 1521 00:56:32,280 --> 00:56:34,280 TYPES OF VERY PRIMITIVE 1522 00:56:34,280 --> 00:56:35,520 PROKARYOTS THAT NICK TALKED 1523 00:56:35,520 --> 00:56:39,360 ABOUT, THE ME THAN GENERALS AND 1524 00:56:39,360 --> 00:56:40,760 THE ASSET GENERALS. 1525 00:56:40,760 --> 00:56:42,360 THEY'RE PRO DEUTING CARBON 1526 00:56:42,360 --> 00:56:43,480 DIOXIDE AND HYDROGEN, THEY ARE 1527 00:56:43,480 --> 00:56:46,920 THE BACTERIA, AND THE 1528 00:56:46,920 --> 00:56:47,920 METHANOGENS ARE PRODUCING 1529 00:56:47,920 --> 00:56:48,240 METHANE. 1530 00:56:48,240 --> 00:56:51,880 AND IT'S A COLLABORATION BETWEEN 1531 00:56:51,880 --> 00:56:53,640 THESE TWO DIFFERENT PROKARYOTS 1532 00:56:53,640 --> 00:56:57,440 THAT GIVES RISE TO AN ENDO 1533 00:56:57,440 --> 00:57:00,680 SYMBIOTIC SYSTEM THAT ULTIMATELY 1534 00:57:00,680 --> 00:57:02,280 MOVES INTO THE CREATION OF A 1535 00:57:02,280 --> 00:57:03,320 COMPLEX EUKARYOTIC CELL. 1536 00:57:03,320 --> 00:57:07,600 SO LET'S TAKE A CLOSER LOOK AT 1537 00:57:07,600 --> 00:57:07,800 THIS. 1538 00:57:07,800 --> 00:57:11,440 I DON'T KNOW WHETHER YOU CAN 1539 00:57:11,440 --> 00:57:12,680 SEE -- IS THIS -- IS THERE A 1540 00:57:12,680 --> 00:57:13,880 PANEL UP HERE THAT BLOCKS PEOPLE 1541 00:57:13,880 --> 00:57:15,320 FROM SEEING THE TITLE OF THESE 1542 00:57:15,320 --> 00:57:15,560 SLIDES? 1543 00:57:15,560 --> 00:57:18,720 I'M JUST CURIOUS. 1544 00:57:18,720 --> 00:57:20,160 I CAN'T GET RID OF IT. 1545 00:57:20,160 --> 00:57:24,440 ANYWAY, BEAR WITH ME. 1546 00:57:24,440 --> 00:57:26,920 BASICALLY THIS IS JUST A ZOOM-UP 1547 00:57:26,920 --> 00:57:28,680 OF THIS METABOLIC SIM BUY OH 1548 00:57:28,680 --> 00:57:30,880 CYST MODEL WHERE WE HAVE THESE 1549 00:57:30,880 --> 00:57:33,080 TWO DIFFERENT TYPES OF 1550 00:57:33,080 --> 00:57:35,680 PROKARYOTS THAT BASICALLY ONCE 1551 00:57:35,680 --> 00:57:38,840 THEY BEGIN SORT OF INTERACTING 1552 00:57:38,840 --> 00:57:40,520 METABOLICALLY AND ULTIMATELY 1553 00:57:40,520 --> 00:57:46,560 WHEN THE ALPHA -- THE ACETOGEN 1554 00:57:46,560 --> 00:57:48,680 GETS TAKEN UP INTO THAT, WHAT 1555 00:57:48,680 --> 00:57:52,880 EMERGES IS AN INCREASED ENERGY 1556 00:57:52,880 --> 00:57:54,080 DEPENDENCE AS WELL AS 1557 00:57:54,080 --> 00:57:55,320 POTENTIALLY ENERGY OUTPUT IN 1558 00:57:55,320 --> 00:57:57,240 THAT SYSTEM. 1559 00:57:57,240 --> 00:58:01,400 AND IT'S THIS ENERGY DEPENDENCE 1560 00:58:01,400 --> 00:58:02,680 AND OUTPUT THAT I WANT TO FOCUS 1561 00:58:02,680 --> 00:58:06,200 ON RIGHT NOW, BASICALLY WHAT'S 1562 00:58:06,200 --> 00:58:08,880 THE BASIS OF THIS INCREASE 1563 00:58:08,880 --> 00:58:10,080 ENERGY DEPENDENCE. 1564 00:58:10,080 --> 00:58:12,440 AND FOR THAT, I'M GOING TO SORT 1565 00:58:12,440 --> 00:58:15,080 OF MOVE TO WHAT NICK TALKED 1566 00:58:15,080 --> 00:58:17,560 ABOUT, WHICH IS THIS UNEXPECTED 1567 00:58:17,560 --> 00:58:19,080 ASPECT OF THE ENERGY OF LIFE. 1568 00:58:19,080 --> 00:58:20,960 WHICH IS THAT CELLS ARE DERIVING 1569 00:58:20,960 --> 00:58:24,440 ENERGY FROM REALLY ONE TYPE, ONE 1570 00:58:24,440 --> 00:58:25,680 MAJOR TYPE OF CHEMICAL REACTION, 1571 00:58:25,680 --> 00:58:28,200 AND THAT IS FLOW OF PROTONS 1572 00:58:28,200 --> 00:58:33,120 ACROSS A MEMBRANE. 1573 00:58:33,120 --> 00:58:35,760 THIS, AS NICK SAID, IS WHY MANY 1574 00:58:35,760 --> 00:58:38,480 PEOPLE THINK IS ONE OF THE MOST 1575 00:58:38,480 --> 00:58:39,560 COUNTERINTUITIVE IDEAS SINCE 1576 00:58:39,560 --> 00:58:40,520 DARWIN, BUT BASICALLY IT WAS 1577 00:58:40,520 --> 00:58:41,800 PROPOSED BY PETER MITCHELL, AND 1578 00:58:41,800 --> 00:58:46,360 IT'S THE CROSS MEMBRANE PROTEIN 1579 00:58:46,360 --> 00:58:50,240 GRADIENT THAT PETER PROPOSED 1580 00:58:50,240 --> 00:58:53,200 DROVE ENERGY METABOLISM WITHIN 1581 00:58:53,200 --> 00:58:53,520 CELLS. 1582 00:58:53,520 --> 00:58:55,240 IN PARTICULAR, HE WAS USING TO 1583 00:58:55,240 --> 00:58:57,320 DESCRIBE THE MITOCHONDRIAL 1584 00:58:57,320 --> 00:58:58,280 RESPIRATORY CHAIN AND THE WAY 1585 00:58:58,280 --> 00:59:02,280 THAT IT IS PRODUCING ATP 1586 00:59:02,280 --> 00:59:05,080 BASICALLY, THESE ARE THE VARIOUS 1587 00:59:05,080 --> 00:59:07,280 ENZYMES, SUBUNITS THAT ARE PART 1588 00:59:07,280 --> 00:59:09,280 OF THIS ELECTRON TRANSPORT 1589 00:59:09,280 --> 00:59:11,160 CHAIN, BUT BASE BASICALLY WHAT 1590 00:59:11,160 --> 00:59:15,280 THEY'RE DOING IS PUMPING PROTONS 1591 00:59:15,280 --> 00:59:17,720 ACROSS THIS MEMBRANE BILAYER 1592 00:59:17,720 --> 00:59:21,800 AND, AS A CONSEQUENCE, CREATING 1593 00:59:21,800 --> 00:59:23,680 AN ELECTROPOTENTIAL GRADIENT. 1594 00:59:23,680 --> 00:59:28,120 NOW, WE KNOW THAT ALL LIVING -- 1595 00:59:28,120 --> 00:59:32,680 WELL, BASED ON WHAT NICK SAID, 1596 00:59:32,680 --> 00:59:33,920 ALL LIVING CELLS ARE POWERING 1597 00:59:33,920 --> 00:59:35,280 THEMSELVES THROUGH THIS TYPE OF 1598 00:59:35,280 --> 00:59:35,840 MECHANISM. 1599 00:59:35,840 --> 00:59:40,480 SO BOTH ARCHAEA AS WELL AS TACK 1600 00:59:40,480 --> 00:59:43,480 BACTERIA USE THIS TYPE OF CHEMO 1601 00:59:43,480 --> 00:59:44,760 OSMOTIC COUPLING TO DRIVE THEIR 1602 00:59:44,760 --> 00:59:45,280 ENERGY PRODUCTION. 1603 00:59:45,280 --> 00:59:48,120 SO A QUESTION IS WHETHER THERE 1604 00:59:48,120 --> 00:59:50,920 ARE DIFFERENCES IN THE WAY THAT 1605 00:59:50,920 --> 00:59:52,440 ARCHAEA AND BACTERIA ARE DOING 1606 00:59:52,440 --> 00:59:56,200 THIS, THAT MIGHT PROVIDE CLUES 1607 00:59:56,200 --> 00:59:59,240 AS TO WHY HAVING A SYMBIOTIC 1608 00:59:59,240 --> 01:00:02,200 RELATIONSHIP BETWEEN ARCHAEA AND 1609 01:00:02,200 --> 01:00:04,480 BACTERIA MIGHT PRODUCE A SYSTEM 1610 01:00:04,480 --> 01:00:06,560 THAT CAN GIVE EMERGENT 1611 01:00:06,560 --> 01:00:09,120 PROPERTIES TO LIFE, IE, A 1612 01:00:09,120 --> 01:00:09,600 EUKARYOTIC CELL. 1613 01:00:09,600 --> 01:00:16,360 SO LET'S LOOK AT LET'S LOOK AT 1614 01:00:16,360 --> 01:00:17,280 THE TWO DIFFERENT WAYS THAT 1615 01:00:17,280 --> 01:00:18,480 ARCHAEA AND BACTERIA ARE DOING 1616 01:00:18,480 --> 01:00:18,720 THIS. 1617 01:00:18,720 --> 01:00:19,800 ONE OF THE WAYS THAT I THINK 1618 01:00:19,800 --> 01:00:23,080 SORT OF POPS UP IS IF WE LOOK AT 1619 01:00:23,080 --> 01:00:25,840 THE PHOSPHOLIPIDS THAT ARE 1620 01:00:25,840 --> 01:00:30,080 CHARACTERIZING ARCHAEA VERSUS 1621 01:00:30,080 --> 01:00:30,680 BACTERIA, NICK MENTIONED THEY 1622 01:00:30,680 --> 01:00:32,080 ARE DIFFERENT, YES INDEED THEY 1623 01:00:32,080 --> 01:00:33,160 ARE, BUT WHAT'S REALLY 1624 01:00:33,160 --> 01:00:34,120 INTERESTING IS THE DIFFERENCE 1625 01:00:34,120 --> 01:00:39,360 BETWEEN THE LINKAGE OF THE 1626 01:00:39,360 --> 01:00:45,680 PHOSPHOLIPID SIDE CHAIN, TO THE 1627 01:00:45,680 --> 01:00:46,120 HEAD GROUP. 1628 01:00:46,120 --> 01:00:48,280 IN THE CASE OF ARCHAEA, IT IS 1629 01:00:48,280 --> 01:00:51,920 MEDIATED BY AN ETHER LINKAGE, 1630 01:00:51,920 --> 01:00:53,680 WHEREAS IN THE CASE OF BACTERIA, 1631 01:00:53,680 --> 01:00:55,800 IT'S AN ESTER LINKAGE. 1632 01:00:55,800 --> 01:00:57,440 AND THAT TURNS OUT TO 1633 01:00:57,440 --> 01:00:59,040 POTENTIALLY BE EXTREMELY 1634 01:00:59,040 --> 01:01:01,720 IMPORTANT IN TERMS OF REGULATING 1635 01:01:01,720 --> 01:01:04,800 THE FLOW OF PROTEINS -- PROTONS 1636 01:01:04,800 --> 01:01:10,480 ACROSS BACTERIAL MEMBRANES. 1637 01:01:10,480 --> 01:01:12,360 RECENTLY, MARIA MENCIA, A 1638 01:01:12,360 --> 01:01:15,280 THEORETICAL AND A BIOCHEMIST, 1639 01:01:15,280 --> 01:01:20,400 HAS PROPOSED THAT WITH ESTER 1640 01:01:20,400 --> 01:01:21,680 LINKAGES IN LIPIDS, THE 1641 01:01:21,680 --> 01:01:23,360 PROTONS COULD POTENTIALLY FLOW 1642 01:01:23,360 --> 01:01:26,080 MORE FLUIDLY THROUGH THE 1643 01:01:26,080 --> 01:01:29,080 MEMBRANE -- THE INNER PART OF 1644 01:01:29,080 --> 01:01:32,440 THE BILAYER, IN CONTRAST TO 1645 01:01:32,440 --> 01:01:35,040 PHOSPHOLIPIDS THAT HAVE ETHER 1646 01:01:35,040 --> 01:01:35,360 LINKAGES. 1647 01:01:35,360 --> 01:01:37,280 WHERE YOU DON'T HAVE THE ABILITY 1648 01:01:37,280 --> 01:01:39,720 TO JUST FLOW THESE PROTONS 1649 01:01:39,720 --> 01:01:40,840 ACROSS THE MEMBRANE. 1650 01:01:40,840 --> 01:01:44,960 AND THAT WOULD FACILITATE THE 1651 01:01:44,960 --> 01:01:47,520 ABILITY OF THE ENZYMES IN THE 1652 01:01:47,520 --> 01:01:48,200 ELECTRON TRANSPORT CHAIN TO BE 1653 01:01:48,200 --> 01:01:56,560 ABLE TO BE COUPLED TO DRIVE FAST 1654 01:01:56,560 --> 01:01:56,960 PROTON FLUX. 1655 01:01:56,960 --> 01:01:58,480 THIS COULD BE -- AND THIS IS 1656 01:01:58,480 --> 01:02:00,480 VERY SPECULATIVE, BUT THIS 1657 01:02:00,480 --> 01:02:02,200 DIFFERENCE IN PROTON PUMPING 1658 01:02:02,200 --> 01:02:04,400 EFFICIENCY, IT MIGHT HELP 1659 01:02:04,400 --> 01:02:05,680 EXPLAIN SOME OF THE DIFFERENCES 1660 01:02:05,680 --> 01:02:07,960 IN ARCHAEA AND BACTERIAL 1661 01:02:07,960 --> 01:02:09,240 HABITATS AND CHARACTERISTICS. 1662 01:02:09,240 --> 01:02:12,040 WE KNOW THAT AT LEAST TODAY, 1663 01:02:12,040 --> 01:02:13,320 ARCHAEA, IF YOU WANT TO FIND 1664 01:02:13,320 --> 01:02:15,920 THEM, YOU'VE GOT TO GO TO 1665 01:02:15,920 --> 01:02:18,800 EXTREME ENVIRONMENTS, EITHER 1666 01:02:18,800 --> 01:02:22,600 THESE SULFUR PONDS OR THESE HOT 1667 01:02:22,600 --> 01:02:24,920 POOLS, AND IF YOU TRY TO GROW 1668 01:02:24,920 --> 01:02:26,200 THESE ARCHAEA, YOU FIND THEY 1669 01:02:26,200 --> 01:02:27,960 TYPICALLY ARE EXTREMELY 1670 01:02:27,960 --> 01:02:30,040 SLOW-GROWING. 1671 01:02:30,040 --> 01:02:31,720 BACTERIA, ON THE OTHER HAND, 1672 01:02:31,720 --> 01:02:33,840 GROW EXTREMELY FAST, AND YOU CAN 1673 01:02:33,840 --> 01:02:35,280 FIND THEM ALL OVER THE PLACE. 1674 01:02:35,280 --> 01:02:36,960 THIS IS JUST IN THE SOIL, 1675 01:02:36,960 --> 01:02:38,880 BASICALLY YOU PICK UP SOME SOIL, 1676 01:02:38,880 --> 01:02:44,080 IT'S JUST FULL OF BACTERIA. 1677 01:02:44,080 --> 01:02:46,520 SO THAT RAISES OF QUESTION OF, 1678 01:02:46,520 --> 01:02:48,960 OKAY, IF BACTERIA IS SO GOOD AT 1679 01:02:48,960 --> 01:02:51,360 GROWING, AND CAN FLOW PROTON% 1680 01:02:51,360 --> 01:02:55,520 REALLY FAST TO GIVE YOU A LOT OF 1681 01:02:55,520 --> 01:02:58,560 ENERGY, WHY DIDN'T BACTERIA 1682 01:02:58,560 --> 01:03:00,120 BECOME A EUKARYOTIC CELL? 1683 01:03:00,120 --> 01:03:02,480 WHY CAN'T WE SCALE UP A BACTERIA 1684 01:03:02,480 --> 01:03:08,560 TO MAKE IT A EUKARYOTIC-LIKE 1685 01:03:08,560 --> 01:03:08,760 CELL? 1686 01:03:08,760 --> 01:03:10,160 THE PROBLEM IS THAT BACTERIA HAS 1687 01:03:10,160 --> 01:03:12,480 A VERY SMALL AMOUNT OF DNA. 1688 01:03:12,480 --> 01:03:15,680 AND THAT DNA IS LARGELY DEVOTED, 1689 01:03:15,680 --> 01:03:17,320 OR A LARGE CHUNK OF IT IS 1690 01:03:17,320 --> 01:03:19,440 DEVOTED TO DRIVING THE 1691 01:03:19,440 --> 01:03:21,240 PRODUCTION OF THE PROTEINS THAT 1692 01:03:21,240 --> 01:03:25,360 ARE COMPRISING THE ELECTRON 1693 01:03:25,360 --> 01:03:26,080 TRANSPORT CHAIN ON ITS SURFACE 1694 01:03:26,080 --> 01:03:28,200 FOR ENERGY PRODUCTION. 1695 01:03:28,200 --> 01:03:31,440 SO THE THINKING IS THAT THE 1696 01:03:31,440 --> 01:03:32,280 BACTERIA'S GENOME IS JUST TOO 1697 01:03:32,280 --> 01:03:36,400 SMALL TO SUPPORT THE ENERGY 1698 01:03:36,400 --> 01:03:38,440 NEEDS OF A CELL THAT SWELLS UP. 1699 01:03:38,440 --> 01:03:41,000 BASICALLY YOU'RE NOT GOING TO 1700 01:03:41,000 --> 01:03:42,280 GET THIS DNA TO BE ABLE TO 1701 01:03:42,280 --> 01:03:46,880 COUPLE ITSELF IN TERMS OF ITS 1702 01:03:46,880 --> 01:03:48,840 PRODUCTION OF PROTEINS, 1703 01:03:48,840 --> 01:03:49,760 TRANSCRIPTION AND TRANSLATION TO 1704 01:03:49,760 --> 01:03:51,280 MATCH WHAT'S GOING ON IN THIS 1705 01:03:51,280 --> 01:03:54,720 LARGE SYSTEM. 1706 01:03:54,720 --> 01:03:56,360 WHY NOT JUST PUT A WHOLE BUNCH 1707 01:03:56,360 --> 01:03:59,080 OF BACTERIA DNA INTO WHY DOESN'T 1708 01:03:59,080 --> 01:04:00,480 THE BACTERIA JUST SWELL, WITH 1709 01:04:00,480 --> 01:04:02,880 YOU BUT 1710 01:04:02,880 --> 01:04:04,440 ALSO JUST MAKE A WHOLE BUNCH OF 1711 01:04:04,440 --> 01:04:05,680 COPIES OF ITS GENOME. 1712 01:04:05,680 --> 01:04:12,200 THIS ALSO HAS A PROBLEM BECAUSE 1713 01:04:12,200 --> 01:04:16,480 ALSO WE KNOW COULD BE -- THE 1714 01:04:16,480 --> 01:04:17,160 PROTEINS THAT ULTIMATELY ARE 1715 01:04:17,160 --> 01:04:19,400 GOING TO BE READ OUT FROM THIS 1716 01:04:19,400 --> 01:04:21,360 GENOME AGAIN HAVE THE PROBLEM IN 1717 01:04:21,360 --> 01:04:25,080 THE CASE OF PROTEINS THAT ARE 1718 01:04:25,080 --> 01:04:26,040 INVOLVED IN THE ELECTRON 1719 01:04:26,040 --> 01:04:33,240 TRANSPORT CHAIN OF FINDING THIS 1720 01:04:33,240 --> 01:04:35,360 MEMBRANE OF ENERGY FLUX TO DRIVE 1721 01:04:35,360 --> 01:04:35,680 PRODUCTION. 1722 01:04:35,680 --> 01:04:36,360 SO BASICALLY WHAT THE ANSWER 1723 01:04:36,360 --> 01:04:37,920 SEEMS TO HAVE BEEN IN THE CASE 1724 01:04:37,920 --> 01:04:44,000 OF EUKARYOTIC EVOLUTION IS TO 1725 01:04:44,000 --> 01:04:45,440 KEEP THE SMALL SIZE OF A 1726 01:04:45,440 --> 01:04:46,320 BACTERIUM THAT IS REALLY 1727 01:04:46,320 --> 01:04:49,080 SUPPORTING THE ENERGY NEEDS OF 1728 01:04:49,080 --> 01:04:52,120 THE CELL, BUT IT JUST INHABIT A 1729 01:04:52,120 --> 01:04:53,080 LARGER VIERM. 1730 01:04:53,080 --> 01:04:55,840 AND THIS IS ENVIRONMENT. 1731 01:04:55,840 --> 01:04:57,440 THIS IS BASICALLY WHAT THE 1732 01:04:57,440 --> 01:04:58,040 EUKARYOTIC CELL IS. 1733 01:04:58,040 --> 01:05:00,280 IT'S A BIGGER CELL THAT'S RUN BY 1734 01:05:00,280 --> 01:05:02,360 MULTIPLE POWER UNITS, WHICH ARE 1735 01:05:02,360 --> 01:05:02,720 MITOCHONDRIA. 1736 01:05:02,720 --> 01:05:04,760 SO EACH OF THESE MITOCHONDRIA 1737 01:05:04,760 --> 01:05:07,080 HAVE THEIR MEMBRANE CLOSE AROUND 1738 01:05:07,080 --> 01:05:08,520 THEM, THEY'RE CHURNING OUT 1739 01:05:08,520 --> 01:05:12,200 PROTEINS THAT ARE GOING TO DRIVE 1740 01:05:12,200 --> 01:05:14,920 THE ENERGY PRODUCTION FOR THIS 1741 01:05:14,920 --> 01:05:18,960 EUKARYOTIC CELL. 1742 01:05:18,960 --> 01:05:22,280 SO THIS TYPE OF THINKING HAS 1743 01:05:22,280 --> 01:05:23,120 SOME IMPLICATIONS. 1744 01:05:23,120 --> 01:05:25,880 ONE IMPLICATION IS THAT THE 1745 01:05:25,880 --> 01:05:26,560 PROTEOBACTERIA THAT HAS BEEN 1746 01:05:26,560 --> 01:05:30,280 TAKEN UP BY THE ARCHAEA, WHICH 1747 01:05:30,280 --> 01:05:33,920 IS THE MITOCHONDRIA, MUST OR IS 1748 01:05:33,920 --> 01:05:38,720 LIKELY TO HAVE BEEN A MAJOR 1749 01:05:38,720 --> 01:05:40,880 DRIVER FOR EVOLUTION IN THE 1750 01:05:40,880 --> 01:05:42,000 EUKARYOTIC SYSTEM. 1751 01:05:42,000 --> 01:05:44,480 BASICALLY THAT MY TOE CON MITOCHONDRIA IS 1752 01:05:44,480 --> 01:05:46,160 GOING TO REALLY BE REGULATING A 1753 01:05:46,160 --> 01:05:48,840 LOT OF THINGS, AND IS THAT THE 1754 01:05:48,840 --> 01:05:50,280 CASE. 1755 01:05:50,280 --> 01:05:51,480 WELL, WE SHOULD SEE A LOT OF 1756 01:05:51,480 --> 01:05:53,400 FEATURES OF MITOCHONDRIA ALL 1757 01:05:53,400 --> 01:05:55,200 OVER -- OR MARKED ALL OVER THE 1758 01:05:55,200 --> 01:05:57,480 WAY THAT EUKARYOTIC SYSTEM IS 1759 01:05:57,480 --> 01:05:57,680 WORKING. 1760 01:05:57,680 --> 01:05:59,840 AND ONE THING THAT WE 1761 01:05:59,840 --> 01:06:03,360 IMMEDIATELY KNOW IS THAT 1762 01:06:03,360 --> 01:06:04,440 EUKARYOTIC MEMBRANES, AND I WISH 1763 01:06:04,440 --> 01:06:07,920 WE COULD GET RID OF THIS PANEL 1764 01:06:07,920 --> 01:06:09,520 HERE BECAUSE -- YOU CAN'T SEE 1765 01:06:09,520 --> 01:06:11,800 THE TITLE HERE, BUT BASICALLY 1766 01:06:11,800 --> 01:06:15,200 THIS IS JUST A SMALL MICRON 1767 01:06:15,200 --> 01:06:17,240 VOLUME OF A EUKARYOTIC CELL 1768 01:06:17,240 --> 01:06:19,040 WHERE WE'VE SEGMENTED OUT ALL OF 1769 01:06:19,040 --> 01:06:20,680 THE DIFFERENT ORGANELLES WITHIN 1770 01:06:20,680 --> 01:06:22,600 THE SYSTEM, AND WHAT I WANT TO 1771 01:06:22,600 --> 01:06:23,960 JUST DRAW YOUR ATTENTION TO IS 1772 01:06:23,960 --> 01:06:27,600 THAT THE MEMBRANES THAT COMPRISE 1773 01:06:27,600 --> 01:06:29,240 ALL OF THE EUKARYOTIC CELL ARE 1774 01:06:29,240 --> 01:06:31,160 ALL ESTER-LINKED, LIKE BACTERIA. 1775 01:06:31,160 --> 01:06:35,240 THEY'RE NOT ETHER-LINKED. 1776 01:06:35,240 --> 01:06:40,440 SO THE ESTER-LINKED FEATURE OF 1777 01:06:40,440 --> 01:06:43,280 PHOSPHOLIPIDS FOUND IN BACTERIA 1778 01:06:43,280 --> 01:06:45,280 HAS BEEN EMBRACED BY THE 1779 01:06:45,280 --> 01:06:45,640 EUKARYOTIC CELL. 1780 01:06:45,640 --> 01:06:48,680 ALL ITS MEMBRANES ARE 1781 01:06:48,680 --> 01:06:49,600 ESTER-LINKED, THERE'S NONE THAT 1782 01:06:49,600 --> 01:06:50,600 ARE ETHER-LINKED. 1783 01:06:50,600 --> 01:06:51,840 SO BASICALLY THE BACTERIA SORT 1784 01:06:51,840 --> 01:06:56,720 OF PUSHED OUT ANY ARCHAEA-TYPE 1785 01:06:56,720 --> 01:06:58,080 LIPID THAT WAS ETHER LINKED 1786 01:06:58,080 --> 01:06:59,320 DURING THIS EVOLUTIONARY 1787 01:06:59,320 --> 01:06:59,880 PROCESS. 1788 01:06:59,880 --> 01:07:03,720 WE ALSO SEE THE PREEMINENCE OF 1789 01:07:03,720 --> 01:07:05,120 MITOCHONDRIA IN CELL PHYSIOLOGY. 1790 01:07:05,120 --> 01:07:08,160 THIS IS JUST LIVE CELL IMAGING 1791 01:07:08,160 --> 01:07:09,840 OF MY TOE MITOCHONDRIA. 1792 01:07:09,840 --> 01:07:11,880 YOU CAN SEE MITOCHONDRIA ARE 1793 01:07:11,880 --> 01:07:15,000 JUST DISTRIBUTED ALL OVER THE 1794 01:07:15,000 --> 01:07:21,080 CYTOPLASM, THEY'RE HIGHLY 1795 01:07:21,080 --> 01:07:22,600 DYNAMIC, IF WE THEN INTERROGATE 1796 01:07:22,600 --> 01:07:24,280 ALL OF THE FEATURES OF THESE 1797 01:07:24,280 --> 01:07:28,680 MITOCHONDRIA IN TERMS OF THEIR 1798 01:07:28,680 --> 01:07:29,680 FUNCTIONALITIES, WE CAN SEE 1799 01:07:29,680 --> 01:07:33,680 BASICALLY ALL ASPECTS OF CELL 1800 01:07:33,680 --> 01:07:35,880 PHYSIOLOGY REALLY HAVE 1801 01:07:35,880 --> 01:07:38,200 MITOCHONDRIA AT THEIR CORE. 1802 01:07:38,200 --> 01:07:40,480 SO FOR INSTANCE, ALL THE 1803 01:07:40,480 --> 01:07:41,280 BUILDING BLOCKS OF THE CELL, 1804 01:07:41,280 --> 01:07:43,280 WHETHER IT BE NUCLEOTIDE, 1805 01:07:43,280 --> 01:07:47,920 PROTEINS, LIPIDS, ARE ALL MADE 1806 01:07:47,920 --> 01:07:52,240 FROM THE FUNDAMENTAL TCA CYCLE 1807 01:07:52,240 --> 01:07:55,280 OPERATING INSIDE THAT 1808 01:07:55,280 --> 01:07:55,880 MITOCHONDRIA. 1809 01:07:55,880 --> 01:07:57,880 THE MITOCHONDRIA ALSO CAN GIVE 1810 01:07:57,880 --> 01:08:01,720 RISE TO LIPIDS, IT CAN STORE 1811 01:08:01,720 --> 01:08:02,040 LIPIDS. 1812 01:08:02,040 --> 01:08:05,800 IT'S TAKING IN FATTY ACIDS AND 1813 01:08:05,800 --> 01:08:07,680 GLUCOSE THROUGH THIS GLYCOLYTIC 1814 01:08:07,680 --> 01:08:08,960 PATHWAY WHICH FEEDS INTO THIS 1815 01:08:08,960 --> 01:08:11,280 TCA CYCLE, BUT YOU CAN MOVE OUT 1816 01:08:11,280 --> 01:08:12,560 TO STORE LIPIDS, AND I'M GOING 1817 01:08:12,560 --> 01:08:15,280 TO BE TALKING ABOUT THIS LATER 1818 01:08:15,280 --> 01:08:17,360 IN MY PRESENTATION, WHICH PLAYS 1819 01:08:17,360 --> 01:08:18,880 A CRITICAL ROLE IN THE WAY THAT 1820 01:08:18,880 --> 01:08:20,920 CELLS CAN HANDLE STARVATION AND 1821 01:08:20,920 --> 01:08:24,720 DEAL WITH VERY DRAMATIC CHANGES 1822 01:08:24,720 --> 01:08:28,520 IN AVAILABILITY OF NUTRIENTS. 1823 01:08:28,520 --> 01:08:29,960 THE MITOCHONDRIA IS ALSO 1824 01:08:29,960 --> 01:08:31,080 CONTROLLING CELL DEATH, IT'S 1825 01:08:31,080 --> 01:08:34,520 CONTROLLING SIGNALING, IT HAS 1826 01:08:34,520 --> 01:08:37,360 CALCIUM STORAGE DEPOT. 1827 01:08:37,360 --> 01:08:37,880 BASICALLY ALL THE 1828 01:08:37,880 --> 01:08:39,280 CHARACTERISTICS, ALL OF THE 1829 01:08:39,280 --> 01:08:43,880 MACRO MOLECULES THAT ARE -- A 1830 01:08:43,880 --> 01:08:46,480 LOT OF THE METABOLISM OF THE 1831 01:08:46,480 --> 01:08:51,360 CELERILY ARE SN TERRED AROUND CENTERED ARO UND THE 1832 01:08:51,360 --> 01:08:52,440 MITOCHONDRIA AND THE WAY IT'S 1833 01:08:52,440 --> 01:08:52,760 FUNCTIONING. 1834 01:08:52,760 --> 01:08:53,840 SO BASICALLY ALL OF THIS IS 1835 01:08:53,840 --> 01:08:55,400 SUGGESTING THAT THE EUKARYOTIC 1836 01:08:55,400 --> 01:09:01,400 CELL AROSE THROUGH AN ENDO -- A 1837 01:09:01,400 --> 01:09:03,280 SINGLE SYMBIOTIC EVENT BETWEEN 1838 01:09:03,280 --> 01:09:12,320 AN ARCHAEA HOST AND THIS 1839 01:09:12,320 --> 01:09:15,200 MITOCHONDRIAL -- IT'S A 1840 01:09:15,200 --> 01:09:15,920 BACTERIUM THAT ULTIMATELY IS 1841 01:09:15,920 --> 01:09:17,600 GOING TO GIVE RISE TO THE 1842 01:09:17,600 --> 01:09:19,320 MITOCHONDRIA. 1843 01:09:19,320 --> 01:09:27,680 SO THAT THEN RAISES THE QUESTION 1844 01:09:27,680 --> 01:09:30,120 OF HOW DO EUKARYOTIC CELLS GET 1845 01:09:30,120 --> 01:09:32,320 BIG GENOMES AND HOW DO THEY 1846 01:09:32,320 --> 01:09:33,960 BECOME MORPHOLOGICALLY COMPLEX. 1847 01:09:33,960 --> 01:09:35,320 IS THERE A WAY THAT WE CAN START 1848 01:09:35,320 --> 01:09:37,120 THINKING ABOUT THAT TO GET A 1849 01:09:37,120 --> 01:09:41,080 BETTER UNDERSTANDING OF -- WE 1850 01:09:41,080 --> 01:09:49,280 HAD THIS NEW TYPE OF SYNERGY 1851 01:09:49,280 --> 01:09:51,360 BETWEEN SORT OF A METABOLIC 1852 01:09:51,360 --> 01:09:52,920 SYMBIOSIS BETWEEN THESE TWO 1853 01:09:52,920 --> 01:09:55,480 DIFFERENT TYPES OF PRO PROKARYOTS, 1854 01:09:55,480 --> 01:09:57,680 THAT'S GIVEN RISE TO THIS NEW 1855 01:09:57,680 --> 01:09:58,680 FORM, THIS EUKARYOTIC CELL. 1856 01:09:58,680 --> 01:10:00,160 HOW DOES IT GET A BIG GENOME AND 1857 01:10:00,160 --> 01:10:01,880 HOW DOES IT BECOME 1858 01:10:01,880 --> 01:10:02,560 MORPHOLOGICALLY COMPLEX? 1859 01:10:02,560 --> 01:10:04,080 WELL, THE BIGGER GENOME CAN 1860 01:10:04,080 --> 01:10:08,080 EASILY BE SORT OF IMAGINED BY 1861 01:10:08,080 --> 01:10:09,800 BASICALLY BEING POWERED BY ALL 1862 01:10:09,800 --> 01:10:13,800 OF THESE MITOCHONDRIAL ATP POWER 1863 01:10:13,800 --> 01:10:14,240 UNITS. 1864 01:10:14,240 --> 01:10:17,200 A LOT OF THE MITOCHONDRIAL 1865 01:10:17,200 --> 01:10:20,880 GENOME, A LOT OF THE ALPHA 1866 01:10:20,880 --> 01:10:21,880 PROTEOGENOME THAT WAS ORIGINALLY 1867 01:10:21,880 --> 01:10:29,120 FOUND IN THESE ENDOSYMBIANTS 1868 01:10:29,120 --> 01:10:32,600 HAVE NOW MOVED INTO THE NUCLEUS. 1869 01:10:32,600 --> 01:10:33,960 THIS GENOME BECAME EVEN LARGER 1870 01:10:33,960 --> 01:10:36,360 BECAUSE IT BASICALLY IS THE HOME 1871 01:10:36,360 --> 01:10:39,600 TO ALL OF THE ARCHAEA BASED 1872 01:10:39,600 --> 01:10:40,080 GENES. 1873 01:10:40,080 --> 01:10:44,720 SO BASICALLY IT'S NOT HARD TO 1874 01:10:44,720 --> 01:10:49,000 IMAGINE THANK YOU YOU HOW YOU COULD CREAT E A 1875 01:10:49,000 --> 01:10:52,280 BIGGER GENOME POWERED BY 1876 01:10:52,280 --> 01:10:53,480 MULTIPLE -- TO OPERATE IN THAT 1877 01:10:53,480 --> 01:10:53,920 REGIME. 1878 01:10:53,920 --> 01:10:57,080 BUT WHAT'S NOT SO CLEAR IS THE 1879 01:10:57,080 --> 01:11:00,760 EMERGENCE OF THE MORPHOLOGICAL 1880 01:11:00,760 --> 01:11:03,480 COMPLEXITY OF ALL OF THESE 1881 01:11:03,480 --> 01:11:04,560 MEMBRANES AND COMPARTMENTS 1882 01:11:04,560 --> 01:11:05,880 INSIDE THE EUKARYOTIC CELL, AND 1883 01:11:05,880 --> 01:11:06,920 THAT'S WHAT I WANT TO TALK ABOUT 1884 01:11:06,920 --> 01:11:09,480 FOR THE NEXT FIVE MINUTES OR 10 1885 01:11:09,480 --> 01:11:14,840 MINUTES OF THIS TALK. 1886 01:11:14,840 --> 01:11:15,920 BASICALLY WHAT I'M GOING TO 1887 01:11:15,920 --> 01:11:19,360 PROPOSE IS THAT THE PATTERNING 1888 01:11:19,360 --> 01:11:21,800 OF LIPIDS ARE PLAYING A VERY 1889 01:11:21,800 --> 01:11:24,480 CRITICAL ROLE IN THIS TYPE OF 1890 01:11:24,480 --> 01:11:27,320 COMPARTMENTALIZATION, AND 1891 01:11:27,320 --> 01:11:30,680 BASICALLY THE EMERGENCE OF THIS 1892 01:11:30,680 --> 01:11:33,960 INTERNAL COMPLEXITY INSIDE THESE 1893 01:11:33,960 --> 01:11:39,680 EUKARYOTIC CELLS WAS ENABLED BY 1894 01:11:39,680 --> 01:11:43,200 THE PRESENCE OR THE EMERGENCE OF 1895 01:11:43,200 --> 01:11:45,240 PARTICULAR TYPES OF EUKARYOTIC 1896 01:11:45,240 --> 01:11:46,080 LIQUIDS. 1897 01:11:46,080 --> 01:11:47,840 SO EUKARYOTES HAVE A COMBINATION 1898 01:11:47,840 --> 01:11:53,880 OF GLIS ROW PHOSPHOLIPIDS, 1899 01:11:53,880 --> 01:11:55,200 SPHINGOLIPIDS AND CHOLESTEROL, 1900 01:11:55,200 --> 01:11:57,680 WHICH NEITHER BACTERIA HAVE. 1901 01:11:57,680 --> 01:12:03,440 IN PARTICULAR -- DO NOT -- IT'S 1902 01:12:03,440 --> 01:12:06,160 THE PRESENCE OF THAT CLES TROT 1903 01:12:06,160 --> 01:12:09,320 WHICH IS GIVING RISE TO A VERY 1904 01:12:09,320 --> 01:12:10,560 INTERESTING CHARACTERISTIC OF 1905 01:12:10,560 --> 01:12:12,000 MEMBRANES, WHICH IS THEIR 1906 01:12:12,000 --> 01:12:16,920 ABILITY TO PARTITION INTO 1907 01:12:16,920 --> 01:12:21,680 REGIONS WHERE THE STERILE CAN 1908 01:12:21,680 --> 01:12:24,120 ORDER THE SPHIGOLIPIDS THAT CAN 1909 01:12:24,120 --> 01:12:27,400 ORDER A THICKER BIOLAYER INTO 1910 01:12:27,400 --> 01:12:28,480 WHICH THEY PREFERENTIALLY SORT. 1911 01:12:28,480 --> 01:12:29,680 NOW THERE'S A LOT OF INTEREST IN 1912 01:12:29,680 --> 01:12:38,240 THE EVOLUTION OF STEROLS IN 1913 01:12:38,240 --> 01:12:40,840 EUKARYOTES, BUT REALLY IT TOOK 1914 01:12:40,840 --> 01:12:43,600 OFF VERY EARLY IN THE EVOLUTION 1915 01:12:43,600 --> 01:12:47,680 OF EUKARYOTES, THIS STEROL, AND 1916 01:12:47,680 --> 01:12:50,720 MODERN DAY EUKARYOTES THAT CAN'T 1917 01:12:50,720 --> 01:12:53,680 MAKE STEROLS WILL BRING IN 1918 01:12:53,680 --> 01:12:54,880 STEROLS FROM OTHER SOURCES. 1919 01:12:54,880 --> 01:12:59,280 SO STEROLS ARE ABSOLUTELY A 1920 01:12:59,280 --> 01:13:01,400 FUNDAMENTAL PART OF EUKARYOTIC 1921 01:13:01,400 --> 01:13:01,680 MEMBRANES. 1922 01:13:01,680 --> 01:13:07,080 SO I MENTIONED HOW THESE STEROLS 1923 01:13:07,080 --> 01:13:08,480 OR CHOLESTEROL CAN ORDER THESE 1924 01:13:08,480 --> 01:13:09,840 MEMBRANES. 1925 01:13:09,840 --> 01:13:11,240 BASICALLY PHOSPHOLIPIDS ARE 1926 01:13:11,240 --> 01:13:13,560 HIGHLY DISORDERED, THEY'RE 1927 01:13:13,560 --> 01:13:18,200 FLOPPY, MAKES THE MEMBRANES THAT 1928 01:13:18,200 --> 01:13:20,720 CONTAIN JUST PURE PHOSPHOLIPIDS 1929 01:13:20,720 --> 01:13:23,360 ARE LEAKY AND HIGHLY DISORDERED. 1930 01:13:23,360 --> 01:13:24,600 AS SOON AS YOU START ADDING 1931 01:13:24,600 --> 01:13:26,840 SINGLE LIPIDS AND CHOLESTEROL, 1932 01:13:26,840 --> 01:13:27,880 ESPECIALLY THE CHOLESTEROL, YOU 1933 01:13:27,880 --> 01:13:33,000 CAN BEGIN OARING THESE ORDERING MEMBRANES . 1934 01:13:33,000 --> 01:13:34,520 YOU CAN SEE THIS SPARE MEANTLY 1935 01:13:34,520 --> 01:13:36,120 BY JUST TAKING THESE THREE 1936 01:13:36,120 --> 01:13:38,600 CLASSES OF LIPIDS, PUTTING THEM 1937 01:13:38,600 --> 01:13:40,560 IN A VIAL, SHAKING THE FILE UP 1938 01:13:40,560 --> 01:13:42,240 AND YOU'LL SEE, IF YOU CREATE 1939 01:13:42,240 --> 01:13:49,920 RES VEST CREATE 1940 01:13:49,920 --> 01:13:51,960 VESICLES, YOU SEE THEY SEPARATE 1941 01:13:51,960 --> 01:13:54,200 INTO ORDERED AND DISORDERED 1942 01:13:54,200 --> 01:13:55,320 DOMAINS, WHERE THE DISORDERED 1943 01:13:55,320 --> 01:13:57,440 DOMAINS WILL BE PRIMARILY 1944 01:13:57,440 --> 01:13:59,040 PHOSPHOLIPIDS AND THE ORDERED 1945 01:13:59,040 --> 01:14:01,200 DOMAINS WILL BE PRIMARILY SINGLE 1946 01:14:01,200 --> 01:14:02,440 LIPIDS IN CHOLESTEROL. 1947 01:14:02,440 --> 01:14:03,560 IT TURNS OUT WE CAN SEE THIS 1948 01:14:03,560 --> 01:14:07,920 EVEN IN BIOLOGICAL MEMBRANES, IN 1949 01:14:07,920 --> 01:14:09,280 CELLS. 1950 01:14:09,280 --> 01:14:13,680 YOU CAN HYPOTONICLY SWELL OUT A 1951 01:14:13,680 --> 01:14:19,960 VESICLE FROM YOUR CELL, AND IF 1952 01:14:19,960 --> 01:14:24,240 YOU LOIR THE TERRITORY USING 1953 01:14:24,240 --> 01:14:26,080 LIPPED PROBES OF THAT BLEB INTO 1954 01:14:26,080 --> 01:14:31,120 A DISOR'DED AND ORDERED DOMAINS. 1955 01:14:31,120 --> 01:14:33,080 WE'VE RECENTLY INTRODUCED 1956 01:14:33,080 --> 01:14:34,680 FLUORESCENT PROTEINS THAT HAVE 1957 01:14:34,680 --> 01:14:37,200 BEEN PROPOSED TO TARGET TO ORDER 1958 01:14:37,200 --> 01:14:38,880 VERSUS DISORDERED DOMAINS ON TO 1959 01:14:38,880 --> 01:14:41,280 THE PLASMA MEMBRANE OF CELLS. 1960 01:14:41,280 --> 01:14:43,720 IF WE BLEB OUT SOME OF THAT 1961 01:14:43,720 --> 01:14:46,600 PLASMA MEMBRANE AND LOWER OUR 1962 01:14:46,600 --> 01:14:48,640 TEMPERATURE TO DRY PHASE 1963 01:14:48,640 --> 01:14:50,840 SEPARATION, YOU CAN SEE SEPARATE 1964 01:14:50,840 --> 01:14:53,440 TYPES OF PROTEINS, THEY PHASE 1965 01:14:53,440 --> 01:14:56,160 PARTITION INTO DIFFERENT DOMAINS 1966 01:14:56,160 --> 01:14:59,640 IN THESE PLASMA MEMBRANE 1967 01:14:59,640 --> 01:15:00,120 VESICLES. 1968 01:15:00,120 --> 01:15:01,680 THIS IS EXTREMELY INTERESTING 1969 01:15:01,680 --> 01:15:02,760 AND EXCITING BECAUSE WHAT THIS 1970 01:15:02,760 --> 01:15:05,920 IS SAYING IS THAT THE PRESENCE 1971 01:15:05,920 --> 01:15:09,800 OF THESE LIPIDS ALLOWS FOR VERY 1972 01:15:09,800 --> 01:15:13,640 COMPLEX SORTING OF PROTEINS ON 1973 01:15:13,640 --> 01:15:14,880 BIOLOGICAL MEMBRANES IN 1974 01:15:14,880 --> 01:15:15,560 EUKARYOTIC CELLS. 1975 01:15:15,560 --> 01:15:18,880 IT'S NOT CLEAR THAT THIS IS 1976 01:15:18,880 --> 01:15:24,200 POSSIBLE TO THIS EXTENT, IN THE 1977 01:15:24,200 --> 01:15:25,040 PROKARYOTIC KINGDOM. 1978 01:15:25,040 --> 01:15:27,280 NOW, I WANT TO JUST SHARE WITH 1979 01:15:27,280 --> 01:15:29,600 YOU SOME REAL BIOLOGY THAT WE 1980 01:15:29,600 --> 01:15:33,800 THINK UNDERLIES, THAT 1981 01:15:33,800 --> 01:15:35,280 REQUIRES/INVOLVES THIS PHASED 1982 01:15:35,280 --> 01:15:37,120 PORE 1983 01:15:37,120 --> 01:15:37,480 PARTITIONS. 1984 01:15:37,480 --> 01:15:38,680 THIS IS A YEAST VACUOLE FROM A 1985 01:15:38,680 --> 01:15:39,960 YEAST THAT IS WELL-FED, AND YOU 1986 01:15:39,960 --> 01:15:42,880 CAN SEE THAT WHEN WE INTRODUCE A 1987 01:15:42,880 --> 01:15:48,880 MARKER, IN THIS CASE, 1988 01:15:48,880 --> 01:15:50,400 GFP-PHO8 WHICH LIKES BEING IN A 1989 01:15:50,400 --> 01:15:51,960 LIQUID DISORDERED MEMBRANE, AS 1990 01:15:51,960 --> 01:15:53,800 SOON AS WE STARVE THIS YEAST 1991 01:15:53,800 --> 01:15:56,960 CELL, WE CAN SEE THE VACUOLE 1992 01:15:56,960 --> 01:15:58,880 PHASED POSITION INTO THIS SOCCER 1993 01:15:58,880 --> 01:16:00,320 BALL-LIKE PATTERN WHERE THE 1994 01:16:00,320 --> 01:16:02,760 DISORDERED MEMBRANE IS NOW 1995 01:16:02,760 --> 01:16:04,760 SEPARATED FROM THESE BLACK AREAS 1996 01:16:04,760 --> 01:16:07,280 HERE, WHERE THE MEMBRANE IS 1997 01:16:07,280 --> 01:16:09,680 ENRICHED IN STEROLS AND SINGLE 1998 01:16:09,680 --> 01:16:10,200 LIPIDS. 1999 01:16:10,200 --> 01:16:12,400 THIS IS JUST SHOWING, THIS IS A 2000 01:16:12,400 --> 01:16:14,520 FREEZE FRACTURE OF THAT VACUOLE 2001 01:16:14,520 --> 01:16:23,160 FROM THAT STAR STARVED YEAST CELL. 2002 01:16:23,160 --> 01:16:24,600 THIS IS WHAT'S HAPPENING IN THAT 2003 01:16:24,600 --> 01:16:24,840 VACUOLE. 2004 01:16:24,840 --> 01:16:26,680 THIS IS A REAL CELL WHERE WE'RE 2005 01:16:26,680 --> 01:16:28,080 LOOKING AT THIS. 2006 01:16:28,080 --> 01:16:31,040 NOW ONE OF THE THINGS THAT WE'VE 2007 01:16:31,040 --> 01:16:32,000 DONE IN TERMS OF TRYING TO 2008 01:16:32,000 --> 01:16:33,400 ANALYZE HOW THIS PHASED 2009 01:16:33,400 --> 01:16:34,960 PARTITIONING OCCURS AND WHAT ITS 2010 01:16:34,960 --> 01:16:37,520 PURPOSE IS, IS SHOWN HERE 2011 01:16:37,520 --> 01:16:40,320 BASICALLY WHEN THE CELL IS 2012 01:16:40,320 --> 01:16:43,680 STARVED OF GLUCOSE, AUTOPHAGY IS 2013 01:16:43,680 --> 01:16:45,560 INITIATED AND THAT BRINGS 2014 01:16:45,560 --> 01:16:49,680 MEMBRANES FROM THE ENDO CYTIC -- 2015 01:16:49,680 --> 01:16:54,200 TO THE VACUOLE. 2016 01:16:54,200 --> 01:16:56,880 STEROL ABUNDANCE IN THAT VACUOLE 2017 01:16:56,880 --> 01:16:58,440 START DRIVING PHASED 2018 01:16:58,440 --> 01:16:59,360 PARTITIONING ON THAT VK YOU'LL, 2019 01:16:59,360 --> 01:17:02,800 AND THAT, THEN, LEADS TO THE 2020 01:17:02,800 --> 01:17:05,680 ABILITY OF THE VACUOLE TO START 2021 01:17:05,680 --> 01:17:07,800 MAKING CONTACT WITH PARTICULAR 2022 01:17:07,800 --> 01:17:09,040 ORGANELLES, IN PARTICULAR, THE 2023 01:17:09,040 --> 01:17:10,960 ENDO PLASMIC RETICULUM, WHICH 2024 01:17:10,960 --> 01:17:13,440 ITSELF CAN MAKE CONTACT WITH THE 2025 01:17:13,440 --> 01:17:14,840 MITOCHONDRIA. 2026 01:17:14,840 --> 01:17:16,080 AND BASICALLY WHAT WE'RE 2027 01:17:16,080 --> 01:17:18,440 PROPOSING IS THAT THIS ENABLES A 2028 01:17:18,440 --> 01:17:22,200 LIPID PIPELINE TO FLOW INTO THE 2029 01:17:22,200 --> 01:17:23,560 MITOCHONDRIA UNDER STARVATION 2030 01:17:23,560 --> 01:17:24,080 CONDITIONS. 2031 01:17:24,080 --> 01:17:25,280 BECAUSE WHAT WE FIND IN THESE 2032 01:17:25,280 --> 01:17:27,440 YEAST CELLS IS THAT WHEN THEY 2033 01:17:27,440 --> 01:17:29,520 UNDERGO STARVATION, THEY ARE 2034 01:17:29,520 --> 01:17:34,560 VERY HAPPY, THEY CAN SURVIVE 50 2035 01:17:34,560 --> 01:17:35,720 DAYS UNDER ACUTE GLUCOSE 2036 01:17:35,720 --> 01:17:37,080 RESTRICTION, AND WHAT HAPPENS IS 2037 01:17:37,080 --> 01:17:39,880 THE MITOCHONDRIA ACTUALLY 2038 01:17:39,880 --> 01:17:40,520 PROLIFERATE DRAMATICALLY AS YOU 2039 01:17:40,520 --> 01:17:45,680 CAN SEE UNDER THESE CONDITIONS. 2040 01:17:45,680 --> 01:17:47,280 CELL RESPIRATION IS BOOSTED AS 2041 01:17:47,280 --> 01:17:48,480 YOU CAN SEE IN THIS MAP. 2042 01:17:48,480 --> 01:17:50,160 WE LOOK AT OXYGEN CONSUMPTION 2043 01:17:50,160 --> 01:17:51,960 UNDER THIS ACUTE GLUCOSE 2044 01:17:51,960 --> 01:17:53,880 STARVATION OF REGIME, IN 2045 01:17:53,880 --> 01:17:58,400 CONTRAST TO CELLS WHERE WE HAVE 2046 01:17:58,400 --> 01:17:59,680 NOT INITIATED THIS TYPE RESPONSE 2047 01:17:59,680 --> 01:18:01,080 IN TERMS OF PHASED PARTITIONING 2048 01:18:01,080 --> 01:18:02,920 AND THE ABILITY OF THESE 2049 01:18:02,920 --> 01:18:03,680 ORGANELLES TO BEGIN TO 2050 01:18:03,680 --> 01:18:07,120 COMMUNICATE WITH EACH OTHER. 2051 01:18:07,120 --> 01:18:10,640 SO BASICALLY THIS IS JUST AN 2052 01:18:10,640 --> 01:18:13,800 EXAMPLE WHERE WE SEE THAT THE 2053 01:18:13,800 --> 01:18:19,320 CELL IN ADAPTING ITS PATHWAYS 2054 01:18:19,320 --> 01:18:21,360 FOR DEALING WITH DIFFERENT TYPES 2055 01:18:21,360 --> 01:18:23,080 OF NUTRIENT STRESSES, 2056 01:18:23,080 --> 01:18:24,120 MITOCHONDRIA IS PLAYING A KEY 2057 01:18:24,120 --> 01:18:24,800 ROLE. 2058 01:18:24,800 --> 01:18:26,720 THERE ARE PATHWAYS THAT ARE 2059 01:18:26,720 --> 01:18:28,280 ENGAGED TO SPECIFICALLY FEED 2060 01:18:28,280 --> 01:18:30,680 FATTY ACIDS INTO THAT 2061 01:18:30,680 --> 01:18:32,800 MITOCHONDRIA, AND ALSO ENABLE 2062 01:18:32,800 --> 01:18:34,400 THAT MITOCHONDRIA TO GROW ITS 2063 01:18:34,400 --> 01:18:40,520 MEMBRANES IN ORDER TO GIVE THE 2064 01:18:40,520 --> 01:18:42,000 CELL ATP UNDER THESE 2065 01:18:42,000 --> 01:18:44,880 NUTRIENT-RESTRICT RESTRICTED REGIMES. 2066 01:18:44,880 --> 01:18:46,240 SO BASICALLY WHAT I'D LIKE TO 2067 01:18:46,240 --> 01:18:47,560 PROPOSE IS THAT THE APPEARANCE 2068 01:18:47,560 --> 01:18:49,880 OF CHOLESTEROL IN SINGLE LIPIDS 2069 01:18:49,880 --> 01:18:51,000 IN MEMBRANES COULD BE WHAT MIGHT 2070 01:18:51,000 --> 01:18:53,560 BE CALLED AN EVENT HORIZON FOR 2071 01:18:53,560 --> 01:18:59,280 EUKARYOTIC CELL EVOLUTION. 2072 01:18:59,280 --> 01:19:04,280 AND IT'S ENABLING BECAUSE IT'S 2073 01:19:04,280 --> 01:19:04,880 ALLOWING MEMBRANE 2074 01:19:04,880 --> 01:19:05,320 COMPARTMENTIZATION AND 2075 01:19:05,320 --> 01:19:05,760 TRAFFICKING. 2076 01:19:05,760 --> 01:19:07,280 BASICALLY IT'S ONLY BY BEING 2077 01:19:07,280 --> 01:19:08,560 ABLE TO PARTITION THESE 2078 01:19:08,560 --> 01:19:10,440 MEMBRANES THAT YOU CAN GET 2079 01:19:10,440 --> 01:19:12,640 PREFERENTIAL SORTING OF 2080 01:19:12,640 --> 01:19:12,880 PROTEINS. 2081 01:19:12,880 --> 01:19:14,480 NOW THE SUPPORT FOR THIS IS THAT 2082 01:19:14,480 --> 01:19:17,560 WE KNOW THAT BACTERIAL 2083 01:19:17,560 --> 01:19:19,840 MEMBRANES, IT'S ONLY BACTERIAL 2084 01:19:19,840 --> 01:19:22,440 MEMBRANES THAT HAVE STEROL LN 2085 01:19:22,440 --> 01:19:25,400 LIKE LIPIDS, ARCHAEA DON'T HAVE 2086 01:19:25,400 --> 01:19:28,320 ANY HINT OF THAT. 2087 01:19:28,320 --> 01:19:31,360 NEITHER BACTERIA OR ARCHAEA HAVE 2088 01:19:31,360 --> 01:19:35,440 TRUE STEROLS IN THEIR MEMBRANES, 2089 01:19:35,440 --> 01:19:37,880 AND BASICALLY WE KNOW 2090 01:19:37,880 --> 01:19:38,920 MITOCHONDRIA ARE COLLABORATING 2091 01:19:38,920 --> 01:19:40,800 WITH OTHER ORGANELLES IN 2092 01:19:40,800 --> 01:19:41,600 CHOLESTEROL BIOSYNTHESIS AND 2093 01:19:41,600 --> 01:19:42,880 THAT THE CHOLESTEROL AND THE 2094 01:19:42,880 --> 01:19:48,160 SINGLE LIPIDS ARE CREATING THESE AND 2095 01:19:48,160 --> 01:19:49,640 LIPID GRADIENTS. 2096 01:19:49,640 --> 01:19:50,840 SO SOME MEMBRANE-SPECIFIC 2097 01:19:50,840 --> 01:19:52,440 SPECULATION, MY THINKING IS THAT 2098 01:19:52,440 --> 01:19:54,400 BASICALLY WITH THE ABILITY TO 2099 01:19:54,400 --> 01:19:59,120 PHASE PARTITION MEMBRANES, THE 2100 01:19:59,120 --> 01:20:04,440 PRIMITIVE GTPASE IS ANOTHER 2101 01:20:04,440 --> 01:20:06,000 PROTEIN INCLUDING ESCORTS WOULD 2102 01:20:06,000 --> 01:20:10,880 THEN BE ABLE TO RAPIDLY EVOLVE. 2103 01:20:10,880 --> 01:20:15,080 SO A LOT OF THE ATP -- THE 2104 01:20:15,080 --> 01:20:18,680 GTPASES THAT ARE SHAPING AND 2105 01:20:18,680 --> 01:20:21,360 DRIVING POLYMERIZATION OF 2106 01:20:21,360 --> 01:20:22,320 VARIOUS CYTOSKELETAL COMPONENTS, 2107 01:20:22,320 --> 01:20:25,360 THEY BASICALLY ARE VERY MUCH 2108 01:20:25,360 --> 01:20:26,320 COUPLED TO BEING ABLE TO 2109 01:20:26,320 --> 01:20:31,600 ASSOCIATE WITH MEMBRANES, AND 2110 01:20:31,600 --> 01:20:32,880 THIS PHASED PARTITIONING MAY BE 2111 01:20:32,880 --> 01:20:33,720 A VERY IMPORTANT PART OF THAT 2112 01:20:33,720 --> 01:20:40,400 PROCESS. 2113 01:20:40,400 --> 01:20:43,320 I'D SAY IT'S ALSO POSSIBLE THIS 2114 01:20:43,320 --> 01:20:50,280 LED TO THE SPECIALIZED -- WE 2115 01:20:50,280 --> 01:20:53,640 KNOW MEMBRANES LIKE THE GOLGI 2116 01:20:53,640 --> 01:20:58,760 APPARATUS CAN COMBINE -- AND 2117 01:20:58,760 --> 01:21:04,320 CREATE TUBULIN ASTERS. 2118 01:21:04,320 --> 01:21:06,560 WITHIN THE CYTOPLASM OF A 2119 01:21:06,560 --> 01:21:08,120 EUKARYOTIC CELL IS VERY MUCH 2120 01:21:08,120 --> 01:21:09,720 DEPENDENT ON SPECIALIZATION OF 2121 01:21:09,720 --> 01:21:12,520 MEMBRANES THAT WILL EITHER 2122 01:21:12,520 --> 01:21:13,600 SEQUESTER OR ACCUMULATE 2123 01:21:13,600 --> 01:21:18,880 DIFFERENT TYPES OF LIPIDS THAT 2124 01:21:18,880 --> 01:21:22,440 RECRUIT KNEW CLEE ATORES FOR 2125 01:21:22,440 --> 01:21:23,240 CYTOSKELETON. 2126 01:21:23,240 --> 01:21:25,160 SO WE THINK THIS MAY HELP 2127 01:21:25,160 --> 01:21:27,160 EXPLAIN WHY PROKARYOTS NEVER 2128 01:21:27,160 --> 01:21:28,880 DEVELOPED MORE COMPLEX 2129 01:21:28,880 --> 01:21:30,400 CYTOSKELETONS, THEY HAD NEITHER 2130 01:21:30,400 --> 01:21:32,640 THE SPECIALIZED MEMBRANES NOR 2131 01:21:32,640 --> 01:21:34,520 THE KNEW CLEE ATORES TO DO THIS. 2132 01:21:34,520 --> 01:21:36,080 SO MY LAST QUESTION IS, WELL, 2133 01:21:36,080 --> 01:21:39,800 HOW CAN WE ADDRESS THESE ISSUES? 2134 01:21:39,800 --> 01:21:41,200 HOW CAN ANY OF WHAT I'VE TALKED 2135 01:21:41,200 --> 01:21:44,440 ABOUT TODAY BE PROVED OR IN ANY 2136 01:21:44,440 --> 01:21:48,240 WAY SUPPORTED. 2137 01:21:48,240 --> 01:21:49,040 BASICALLY I THINK WE'RE GOING TO 2138 01:21:49,040 --> 01:21:51,240 HAVE TO ADDRESS THIS IN I A LOT 2139 01:21:51,240 --> 01:21:52,080 OF DIFFERENT WAYS. 2140 01:21:52,080 --> 01:21:54,320 ONE IS, WE NEED NEW TOOLS TO 2141 01:21:54,320 --> 01:21:55,600 VISUALIZE, PROBE AND MEASURE 2142 01:21:55,600 --> 01:21:57,000 LIPIDS AND PROTEINS WITHIN THE 2143 01:21:57,000 --> 01:21:57,200 CELL. 2144 01:21:57,200 --> 01:21:59,000 WE NEED TO REALLY LOOK AT THIS 2145 01:21:59,000 --> 01:21:59,800 PHASED PARTITIONS AND SEE 2146 01:21:59,800 --> 01:22:02,600 EXACTLY WHAT IT'S DOING. 2147 01:22:02,600 --> 01:22:04,520 WE NEED HIGHER RESOLUTION TO 2148 01:22:04,520 --> 01:22:05,800 EXAMINE PROTEIN DISTRIBUTIONS IN 2149 01:22:05,800 --> 01:22:08,520 RELATION TO LIPIDS WITHIN 2150 01:22:08,520 --> 01:22:12,400 ORGANELLES, AND FINALLY 2151 01:22:12,400 --> 01:22:14,080 MATHEMATICAL MODELING WOULD BE 2152 01:22:14,080 --> 01:22:16,560 INCREDIBLY VALUABLE TO ASSESS 2153 01:22:16,560 --> 01:22:18,480 THE DYNAMICS OF THE SYSTEM, AND 2154 01:22:18,480 --> 01:22:20,520 START LEADING TO OTHER TYPES OF 2155 01:22:20,520 --> 01:22:22,840 HYPOTHESES FOR TESTING SOME OF 2156 01:22:22,840 --> 01:22:23,400 THESE QUESTIONS. 2157 01:22:23,400 --> 01:22:24,920 SO WITH THAT, I WANT TO THANK 2158 01:22:24,920 --> 01:22:29,880 YOU, AND I WILL NOW STOP SHARING 2159 01:22:29,880 --> 01:22:30,680 AND WE CAN BE OPEN FOR 2160 01:22:30,680 --> 01:22:35,680 QUESTIONS. 2161 01:22:35,680 --> 01:22:38,880 >> THANK YOU VERY MUCH, 2162 01:22:38,880 --> 01:22:39,400 JENNIFER. 2163 01:22:39,400 --> 01:22:40,720 NICK, WE DO HAVE A SERIES OF 2164 01:22:40,720 --> 01:22:42,880 QUESTIONS AND I HOPE BOTH OF YOU 2165 01:22:42,880 --> 01:22:43,680 ARE THINKING OF QUESTIONS YOU 2166 01:22:43,680 --> 01:22:47,080 WOULD LIKE TO ADDRESS TO EACH 2167 01:22:47,080 --> 01:22:55,840 OTHER. 2168 01:22:55,840 --> 01:22:57,880 ONE QUESTION THAT'S BEEN ASKED, 2169 01:22:57,880 --> 01:22:59,280 NICK, IS COULD LIFE PERHAPS HAVE 2170 01:22:59,280 --> 01:23:04,880 STARTED A FEW TIMES, MORE THAN 2171 01:23:04,880 --> 01:23:09,120 ONE, ABIOGENESIS? 2172 01:23:09,120 --> 01:23:13,440 IS THERE -- BACTERIA, ARCHAEA, 2173 01:23:13,440 --> 01:23:19,360 AND THE EUKARYOTES MAY HAVE 2174 01:23:19,360 --> 01:23:22,000 ARISEN SEVERAL TIMES OR HAVE 2175 01:23:22,000 --> 01:23:22,640 ARISEN FROM -- 2176 01:23:22,640 --> 01:23:25,080 >> I MEAN, THEY MAY HAVE DONE -- 2177 01:23:25,080 --> 01:23:26,080 THERE'S NO EVIDENCE TO SUPPORT 2178 01:23:26,080 --> 01:23:26,840 THAT. 2179 01:23:26,840 --> 01:23:30,240 I MEAN, PLAINLY LIFE SHARES A 2180 01:23:30,240 --> 01:23:32,840 COMMON ANCESTOR BECAUSE THE 2181 01:23:32,840 --> 01:23:36,520 GENETIC CODE REALLY IS THE 2182 01:23:36,520 --> 01:23:37,800 SINGLE STRONGEST PIECE OF 2183 01:23:37,800 --> 01:23:40,920 EVIDENCE THAT SUGGESTS THAT ALL 2184 01:23:40,920 --> 01:23:41,920 LIFE IS DERIVED FROM THE SAME 2185 01:23:41,920 --> 01:23:42,400 SOURCE. 2186 01:23:42,400 --> 01:23:43,440 NOW RIGHT AT THE END OF MY TALK, 2187 01:23:43,440 --> 01:23:45,520 I SUGGESTED THAT THERE ARE 2188 01:23:45,520 --> 01:23:47,280 BIOPHYSICAL REASONS FOR THE 2189 01:23:47,280 --> 01:23:49,520 CODE, I DON'T THINK THAT WOULD 2190 01:23:49,520 --> 01:23:50,320 EXPLAIN THE WHOLE CODE AND I 2191 01:23:50,320 --> 01:23:53,200 WOULD BE ABSOLUTELY AMAZED IF WE 2192 01:23:53,200 --> 01:23:53,840 FOUND BACTERIA ON MARS OR 2193 01:23:53,840 --> 01:23:55,000 SOMEWHERE LIKE THAT AND THEY HAD 2194 01:23:55,000 --> 01:23:57,440 EXACTLY THE SAME CODE, WE 2195 01:23:57,440 --> 01:23:58,760 CONCLUDED THEY DIDN'T COME FROM 2196 01:23:58,760 --> 01:24:01,680 EARTH OR VICE VERSA. 2197 01:24:01,680 --> 01:24:03,760 IT WOULD BE SHOCKING IF YOU LIKE 2198 01:24:03,760 --> 01:24:05,320 CHEMICAL DETERMINE NISM CAN TAKE 2199 01:24:05,320 --> 01:24:07,080 US RIGHT UP TO THE CODE ITSELF. 2200 01:24:07,080 --> 01:24:07,880 ALL THE WAY. 2201 01:24:07,880 --> 01:24:10,440 IT'S POSSIBLE IT CAN, THOUGH WE 2202 01:24:10,440 --> 01:24:11,880 DON'T KNOW ENOUGH YET, BUT I 2203 01:24:11,880 --> 01:24:12,440 WILL BE SURPRISED. 2204 01:24:12,440 --> 01:24:13,520 NOW THAT DOESN'T MEAN TO SAY 2205 01:24:13,520 --> 01:24:14,720 THAT THERE WEREN'T MULTIPLE 2206 01:24:14,720 --> 01:24:16,720 ORIGINS OF LIFE AND THAT IT 2207 01:24:16,720 --> 01:24:17,680 SIMPLY DISAPPEARED AND THERE'S 2208 01:24:17,680 --> 01:24:18,720 NO EVIDENCE FOR IT, AND WHAT 2209 01:24:18,720 --> 01:24:23,560 WOULD YOU SEE IN A FOSSIL RECORD 2210 01:24:23,560 --> 01:24:25,440 YOU'D SAY SMEARS THAT LOOK A BIT 2211 01:24:25,440 --> 01:24:26,560 LIKE BACTERIA IN THE ROCKS AND 2212 01:24:26,560 --> 01:24:37,960 YOU'D NEVER KNOW WHAT THEY WERE. 2213 01:24:37,960 --> 01:24:41,680 BUT ALL THAT REALLY MEANS IS 2214 01:24:41,680 --> 01:24:42,760 THEY DIDN'T SURVIVE. 2215 01:24:42,760 --> 01:24:44,280 I THINK IN THE CASE OF BACTERIA 2216 01:24:44,280 --> 01:24:45,840 AND ARCHAEA, THERE'S ALMOST A 2217 01:24:45,840 --> 01:24:51,560 MORE DIFFICULT QUESTION ABOUT IF 2218 01:24:51,560 --> 01:24:53,360 THEY SHARED A COMMON ANCESTOR 2219 01:24:53,360 --> 01:24:55,720 AND EMERGED SEPARATELY FROM 2220 01:24:55,720 --> 01:24:59,440 EVENTS, WHY DID IT HAPPEN TWICE, 2221 01:24:59,440 --> 01:25:02,120 WHY DID THEY NOT DIVERGE AT ALL? 2222 01:25:02,120 --> 01:25:04,600 AND I THINK I HAVE SOME THOUGHTS 2223 01:25:04,600 --> 01:25:07,400 ON THAT, BUT THEY'RE NOT 2224 01:25:07,400 --> 01:25:08,320 TERRIBLY WELL THOUGHT THROUGH 2225 01:25:08,320 --> 01:25:10,600 BUT IT'S REALLY TO DO WITH THE 2226 01:25:10,600 --> 01:25:14,680 ORIGIN OF PUP PING. OF PUMPING. 2227 01:25:14,680 --> 01:25:15,840 AS SOON AS YOU CAN PUMP, YOU 2228 01:25:15,840 --> 01:25:19,240 HAVE A TREMENDOUS ADVANTAGE OVER 2229 01:25:19,240 --> 01:25:20,560 CELLS THAT DON'T PUMP. 2230 01:25:20,560 --> 01:25:22,000 THAT'S THE LAST STEP IF YOU LIKE 2231 01:25:22,000 --> 01:25:23,440 OF BECOMING A FREE, INDIVIDUAL 2232 01:25:23,440 --> 01:25:25,080 CELL, IS YOU CAN NOW LEAVE A 2233 01:25:25,080 --> 01:25:25,880 VENT AND YOU CAN LIVE SOMEWHERE 2234 01:25:25,880 --> 01:25:28,480 ELSE. 2235 01:25:28,480 --> 01:25:29,560 SO AS SOON AS CELLS HAD LEFT, 2236 01:25:29,560 --> 01:25:32,280 THEN I THINK DARWIN WAS RIGHT. 2237 01:25:32,280 --> 01:25:34,360 BASICALLY HE SAID ONCE LIFE 2238 01:25:34,360 --> 01:25:35,560 APPEARED, IT'S GOING TO EAT 2239 01:25:35,560 --> 01:25:36,200 EVERYTHING ELSE. 2240 01:25:36,200 --> 01:25:37,120 IT'S GOING TO BE REALLY 2241 01:25:37,120 --> 01:25:39,080 DIFFICULT FOR KIND OF A 2242 01:25:39,080 --> 01:25:40,520 PREBIOTIC SYSTEM IN A 2243 01:25:40,520 --> 01:25:41,800 HYDROTHERMAL VENT TO GET A FOOT 2244 01:25:41,800 --> 01:25:43,320 IN WHEN THERE'S ALREADY CELLS 2245 01:25:43,320 --> 01:25:45,200 OUT THERE, THEY'RE SO MUCH 2246 01:25:45,200 --> 01:25:46,480 BETTER AT WHAT THEY DO. 2247 01:25:46,480 --> 01:25:47,280 JENNIFER, DO YOU HAVE THOUGHTS 2248 01:25:47,280 --> 01:25:51,040 ON THAT? 2249 01:25:51,040 --> 01:25:51,880 >> DIDN'T DARWIN SAY THAT HE 2250 01:25:51,880 --> 01:25:53,440 THOUGHT THAT LIFE EVOLVED IN A 2251 01:25:53,440 --> 01:25:57,080 NICE CALM LITTLE POND, A WORM 2252 01:25:57,080 --> 01:25:59,480 POND? 2253 01:25:59,480 --> 01:25:59,800 WORM 2254 01:25:59,800 --> 01:26:00,280 POND? 2255 01:26:00,280 --> 01:26:01,040 >> YES, HE DID. 2256 01:26:01,040 --> 01:26:03,760 I THINK HE WAS MI STAY MISTAKEN ON THAT 2257 01:26:03,760 --> 01:26:05,040 ONE PERSONALLY, WITH YOU MOST OF 2258 01:26:05,040 --> 01:26:08,000 THE CHEMISTS FOND OF PROTEIN 2259 01:26:08,000 --> 01:26:10,320 CHEMISTRY ARE FOND OF DARWIN, 2260 01:26:10,320 --> 01:26:17,840 THE GREAT GOD GOD DARWIN, THEY 2261 01:26:17,840 --> 01:26:20,760 QUIETLY FORGET ABOUT SOME OF THE 2262 01:26:20,760 --> 01:26:22,560 GENETICS, DARWIN WAS A GENIUS 2263 01:26:22,560 --> 01:26:23,640 BUT HE WASN'T RIGHT ABOUT 2264 01:26:23,640 --> 01:26:24,720 EVERYTHING. 2265 01:26:24,720 --> 01:26:26,280 >> I WAS JUST GOING TO ASK NICK 2266 01:26:26,280 --> 01:26:27,680 A QUESTION, THOUGH IT MAY TAKE 2267 01:26:27,680 --> 01:26:29,280 US INTO A DIFFERENT WORLD, BUT 2268 01:26:29,280 --> 01:26:30,080 ONE OF THE THINGS THAT WAS 2269 01:26:30,080 --> 01:26:33,080 EXCITING ABOUT YOUR REACTOR THAT 2270 01:26:33,080 --> 01:26:36,000 YOU GENERATED IS THAT IT ABLE TO 2271 01:26:36,000 --> 01:26:37,840 REMOVE CO2. 2272 01:26:37,840 --> 01:26:40,320 BASICALLY IT'S PUMPING CO2 OUT 2273 01:26:40,320 --> 01:26:41,000 OF A SYSTEM. 2274 01:26:41,000 --> 01:26:42,280 HAVE YOU THOUGHT ABOUT USING 2275 01:26:42,280 --> 01:26:45,360 THAT AT ALL FOR SORT OF SCALING 2276 01:26:45,360 --> 01:26:47,320 UP FOR GLOBAL WARMING PURPOSES? 2277 01:26:47,320 --> 01:26:48,280 >> ABSOLUTELY. 2278 01:26:48,280 --> 01:26:50,080 I MEAN, FIRST OF ALL WE HAVE TO 2279 01:26:50,080 --> 01:26:53,080 MAKE IT WORK. 2280 01:26:53,080 --> 01:26:54,240 RIGHT NOW IT WORKS A LITTLE BIT 2281 01:26:54,240 --> 01:26:58,280 BUT NOT VERY WELL. 2282 01:26:58,280 --> 01:27:01,120 BUT IT BASICALLY -- I THINK ONE 2283 01:27:01,120 --> 01:27:03,320 OF THE REASONS WHY THESE IDEAS 2284 01:27:03,320 --> 01:27:06,680 ON CO2 AND HYDROGEN ARE COMING 2285 01:27:06,680 --> 01:27:07,840 MORE INTO VOGUE THAN THEY WERE 2286 01:27:07,840 --> 01:27:09,560 10 YEARS AGO, 20 YEARS AGO, WHEN 2287 01:27:09,560 --> 01:27:12,080 ALL THE CHEMISTRY WAS CYANIDE 2288 01:27:12,080 --> 01:27:13,360 CHEMISTRY, NOW THERE'S MORE 2289 01:27:13,360 --> 01:27:15,680 INTEREST IN CAN WE MAKE CO2 2290 01:27:15,680 --> 01:27:17,920 REACT WITH HYDROGEN, AND IT'S 2291 01:27:17,920 --> 01:27:18,880 REALLY ABOUT GLOBAL WARMING AND 2292 01:27:18,880 --> 01:27:19,400 ENERGY SECURITY. 2293 01:27:19,400 --> 01:27:21,640 BECAUSE IF WE CAN STRIP CO2 FROM 2294 01:27:21,640 --> 01:27:22,960 THE ATMOSPHERE, SPLIT WATER, 2295 01:27:22,960 --> 01:27:25,400 TAKE THE HYDROGEN, MAKE 2296 01:27:25,400 --> 01:27:26,240 HYDROCARBONS AND EFFECTIVELY 2297 01:27:26,240 --> 01:27:28,080 HAVE A CARBON NEUTRAL ECONOMY 2298 01:27:28,080 --> 01:27:31,440 WHERE WE DOCHT DON'T HAVE TO CHANGE SO 2299 01:27:31,440 --> 01:27:33,480 MUCH, THAT'S AN IDEAL SOLUTION, 2300 01:27:33,480 --> 01:27:34,400 AND THAT'S WHAT THEY DO, THAT'S 2301 01:27:34,400 --> 01:27:35,240 HOW THEY GROW. 2302 01:27:35,240 --> 01:27:37,080 THERE HAS TO BE A SIMPLE WAY OF 2303 01:27:37,080 --> 01:27:37,880 DOING IT. 2304 01:27:37,880 --> 01:27:40,280 >> -- ATMOSPHERE TOO, YEAH. 2305 01:27:40,280 --> 01:27:40,600 AMAZING. 2306 01:27:40,600 --> 01:27:53,080 >> NICK, YOU TOUCHED ON SEVERAL 2307 01:27:53,080 --> 01:27:53,920 QUESTIONS. 2308 01:27:53,920 --> 01:27:57,560 WOULD YOU ELABORATE AS TO HOW AN 2309 01:27:57,560 --> 01:28:00,560 EARLY MEMBRANE DEVELOPED PUMPING 2310 01:28:00,560 --> 01:28:04,360 ACTIVITY TO MAINTAIN INTERNAL 2311 01:28:04,360 --> 01:28:14,680 AND EXTERNAL MILIEUS? 2312 01:28:14,680 --> 01:28:16,320 >> IN A HYDROTHERMAL SYSTEM, 2313 01:28:16,320 --> 01:28:18,120 WE'VE GOT CONTINUOUS FLOW, SO I 2314 01:28:18,120 --> 01:28:19,640 SUPPOSE THE KEY THING ABOUT 2315 01:28:19,640 --> 01:28:22,320 THESE IDEAS IS THAT PUMPING IS A 2316 01:28:22,320 --> 01:28:25,600 LATE STEP. 2317 01:28:25,600 --> 01:28:27,120 AND WHAT THAT MEANS IS WITHOUT 2318 01:28:27,120 --> 01:28:28,520 PUMPS, PROTONS HAVE TO COME -- 2319 01:28:28,520 --> 01:28:30,080 IF YOU'VE GOT A MODERN MEMBRANE 2320 01:28:30,080 --> 01:28:31,360 WHICH IS EFFECTIVELY CLOSE TO 2321 01:28:31,360 --> 01:28:34,440 BEING PROTON-TIGHT, A COUPLE 2322 01:28:34,440 --> 01:28:36,880 MEMBRANE WE WOULD SEE THAT 2323 01:28:36,880 --> 01:28:38,080 MEMBRANE HAVE, BACTERIA OR 2324 01:28:38,080 --> 01:28:39,640 ARCHAEA HAVE, THAT'S THE LAST 2325 01:28:39,640 --> 01:28:42,640 THING, YOU HAVE A TURBINE, ECH 2326 01:28:42,640 --> 01:28:45,640 OR ANY PIECE OF MOLECULAR 2327 01:28:45,640 --> 01:28:47,000 MACHINERY, PROTON COMES IN AND 2328 01:28:47,000 --> 01:28:48,920 THERE'S NO PUMP TO GET IT OUT 2329 01:28:48,920 --> 01:28:49,920 AGAIN, THEN YOU JUST COLLAPSED 2330 01:28:49,920 --> 01:28:50,640 THE DRIVING FORCE. 2331 01:28:50,640 --> 01:28:52,200 SO WHAT YOU ACTUALLY NEED IS A 2332 01:28:52,200 --> 01:28:54,280 LEAKY MEMBRANE, LEAKY TO PROTONS 2333 01:28:54,280 --> 01:28:55,280 SPECIFICALLY, SO THEY CAN COME 2334 01:28:55,280 --> 01:28:57,040 IN AND THEN THEY'RE SWEPT AWAY 2335 01:28:57,040 --> 01:28:59,880 BY THE FLOW OF ALKALINE FLUIDS, 2336 01:28:59,880 --> 01:29:01,480 THEY REACT WITH THE HYDROXIDE 2337 01:29:01,480 --> 01:29:02,120 IONS. 2338 01:29:02,120 --> 01:29:06,120 SO IT CAN ONLY WORK IF THEY 2339 01:29:06,120 --> 01:29:09,000 DON'T HAVE A MODERN PHOSPHOLIPID 2340 01:29:09,000 --> 01:29:14,880 MEMBRANE THAT LOOKS LIKE -- THEY 2341 01:29:14,880 --> 01:29:16,560 HAVE TO BE MORE OR LESS LEAKY TO 2342 01:29:16,560 --> 01:29:17,880 THE OUTSIDE WORLD FOR THESE 2343 01:29:17,880 --> 01:29:19,080 IDEAS TO WORK AT ALL. 2344 01:29:19,080 --> 01:29:21,040 SO THAT WOULD BE MY EXPLANATION 2345 01:29:21,040 --> 01:29:24,960 FOR WHY BACTERIA AND ARCHAEA 2346 01:29:24,960 --> 01:29:26,200 HAVE QUITE DIFFERENT MEMBRANES. 2347 01:29:26,200 --> 01:29:28,600 THEY AROSE AT THE SAME TIME AS 2348 01:29:28,600 --> 01:29:31,040 PUMPING, SO HOW DID PUMPING 2349 01:29:31,040 --> 01:29:31,240 BEGIN? 2350 01:29:31,240 --> 01:29:32,360 I THINK WE ARE DEALING THEN IN 2351 01:29:32,360 --> 01:29:35,560 THE WORLD OF GENES. 2352 01:29:35,560 --> 01:29:37,080 WE'RE DEALING WITH PROTEINS 2353 01:29:37,080 --> 01:29:39,320 WHICH ARE ENCODED BY GENES WHICH 2354 01:29:39,320 --> 01:29:40,600 ARE CAPABLE OF -- WE'RE DEALING 2355 01:29:40,600 --> 01:29:43,320 WITH MOLECULAR MACHINES. 2356 01:29:43,320 --> 01:29:46,600 SO I PERSONALLY DOUBT THAT THERE 2357 01:29:46,600 --> 01:29:48,760 WERE SOPHISTICATED PUMPS BEFORE 2358 01:29:48,760 --> 01:29:50,280 GENES. THERE ARE WAYS OF DOING 2359 01:29:50,280 --> 01:29:51,160 IT. 2360 01:29:51,160 --> 01:29:54,240 QUINONES, FOR EXAMPLE, CAN PICK 2361 01:29:54,240 --> 01:29:56,280 UP PROTONS AND CARRY THEM ACROSS 2362 01:29:56,280 --> 01:29:58,080 THE MEMBRANE. 2363 01:29:58,080 --> 01:29:59,960 AND IT WOULD DEPEND WHERE THEY 2364 01:29:59,960 --> 01:30:01,720 GO, THEY CAN SHUTTLE BACKWARDS 2365 01:30:01,720 --> 01:30:04,160 AND FORWARDS DEPENDING ON THE 2366 01:30:04,160 --> 01:30:05,040 REDOX DIFFERENCE AND THE PH 2367 01:30:05,040 --> 01:30:05,360 DIFFERENCE. 2368 01:30:05,360 --> 01:30:06,680 SO IT'S POSSIBLE TO HAVE PUMPING 2369 01:30:06,680 --> 01:30:08,440 IN THE ABSENCE OF COMPLEX 2370 01:30:08,440 --> 01:30:09,760 PROTEINS, BUT IF YOU'VE GOT A 2371 01:30:09,760 --> 01:30:11,040 SYSTEM WHERE EFFECTIVELY YOU 2372 01:30:11,040 --> 01:30:12,440 DON'T NEED IT BECAUSE THE VENT 2373 01:30:12,440 --> 01:30:14,280 IS DOING ALL THE WORK, THE VENT 2374 01:30:14,280 --> 01:30:18,080 IS KEEPING THE GRADIENTS THERE, 2375 01:30:18,080 --> 01:30:19,960 THEN I KIND OF DON'T NEED PUMPS 2376 01:30:19,960 --> 01:30:24,360 UNTIL THE END WHERE CELLS 2377 01:30:24,360 --> 01:30:26,040 EFFECTIVELY NEED TO LEAVE OR ARE 2378 01:30:26,040 --> 01:30:27,840 CUT OFF FROM -- THERE WILL BE A 2379 01:30:27,840 --> 01:30:28,880 SELECTIVE ADVANTAGE IF YOU ARE 2380 01:30:28,880 --> 01:30:29,920 IN THE CORNER OF A VENT WHERE 2381 01:30:29,920 --> 01:30:31,400 THERE'S NOT THAT MUCH FLOW AND 2382 01:30:31,400 --> 01:30:33,120 YOU FIGURED OUT A LITTLE BIT HOW 2383 01:30:33,120 --> 01:30:35,040 TO PUMP YOUR OWN PROTONS OUT, 2384 01:30:35,040 --> 01:30:36,440 YOU WILL THRIVE IN THAT REGION 2385 01:30:36,440 --> 01:30:37,720 WHEREAS OTHER CELLS WOULDN'T. 2386 01:30:37,720 --> 01:30:39,440 SO IT'S EASY TO IMAGINE 2387 01:30:39,440 --> 01:30:40,280 SELECTIVE ADVANTAGES, IT'S 2388 01:30:40,280 --> 01:30:44,280 REALLY DIFFICULT TO PROVE ANY OF 2389 01:30:44,280 --> 01:30:44,760 THIS STUFF. 2390 01:30:44,760 --> 01:30:46,000 WE'RE KIND OF STUCK WITH THE 2391 01:30:46,000 --> 01:30:47,080 CENTRAL QUESTIONS THAT WE CAN 2392 01:30:47,080 --> 01:30:48,320 ACTUALLY TEST. 2393 01:30:48,320 --> 01:30:50,320 >> SO COULD YOU HAVE AN 2394 01:30:50,320 --> 01:30:52,200 EXCHANGER WITHOUT HAVING A 2395 01:30:52,200 --> 01:30:52,440 PROTEIN? 2396 01:30:52,440 --> 01:30:54,720 IS THAT WHAT YOU'RE SAYING? 2397 01:30:54,720 --> 01:30:57,400 >> YES, YOU CAN HAVE AN 2398 01:30:57,400 --> 01:30:58,320 EXCHANGER WITHOUT HAVING A 2399 01:30:58,320 --> 01:31:01,560 PROTEIN SO LONG AS IT'S A SEMI 2400 01:31:01,560 --> 01:31:01,960 OPEN SYSTEM. 2401 01:31:01,960 --> 01:31:03,680 STUFF HAS TO COME IN AND LEAVE 2402 01:31:03,680 --> 01:31:03,880 AGAIN. 2403 01:31:03,880 --> 01:31:06,400 IN OTHER WORDS, I MEAN, FROM AN 2404 01:31:06,400 --> 01:31:09,880 ORIGIN OF LIFE POINT OF VIEW, IT 2405 01:31:09,880 --> 01:31:10,520 ACTUALLY VERY GOOD. 2406 01:31:10,520 --> 01:31:11,480 THE LAST THING YOU REALLY WANT 2407 01:31:11,480 --> 01:31:16,360 TO HAVE IS TO SAY RIGHT, I NEED 2408 01:31:16,360 --> 01:31:19,680 A REALLY SOPHISTICATED 2409 01:31:19,680 --> 01:31:21,040 MEMBRANE -- WHAT I'M ACTUALLY 2410 01:31:21,040 --> 01:31:22,640 SAYING IS WE NEED A CRAFTY 2411 01:31:22,640 --> 01:31:25,400 MEMBRANE, WE DON'T NEED ANY 2412 01:31:25,400 --> 01:31:26,640 MOLECULAR MACHINES, WE JUST NEED 2413 01:31:26,640 --> 01:31:29,040 CONTINUOUS FLOW AND A 2414 01:31:29,040 --> 01:31:30,280 HYDROTHERMAL VENT AND THAT'S 2415 01:31:30,280 --> 01:31:31,440 POWERED IN THE END BY GRAVITY. 2416 01:31:31,440 --> 01:31:34,000 SO WE NEED BAD SYSTEMS OR WE 2417 01:31:34,000 --> 01:31:35,880 NEED TO SEE WAYS OF HOW THEY 2418 01:31:35,880 --> 01:31:36,880 WILL GET BETTER, WHY THEY WILL 2419 01:31:36,880 --> 01:31:39,520 GET BETTER AND THOSE STEPS, ALL 2420 01:31:39,520 --> 01:31:41,440 OF THIS -- AS SOON AS WE'VE GOT 2421 01:31:41,440 --> 01:31:43,040 GENES, WHEN I FINISH MY TALK, 2422 01:31:43,040 --> 01:31:46,720 WITH THE BEGINNINGS OF RANDOM 2423 01:31:46,720 --> 01:31:48,720 RNAs BUT NON-RANDOM TEMPLATING 2424 01:31:48,720 --> 01:31:51,680 OF PEPTIDES, THEN WE HAVE 2425 01:31:51,680 --> 01:31:53,040 NATURAL SELECTION AS WE KNOW IT, 2426 01:31:53,040 --> 01:31:56,200 AND SO LONG AS YOU HAVE THE 2427 01:31:56,200 --> 01:31:57,480 POWER TO KEEP GENERATING THESE 2428 01:31:57,480 --> 01:31:59,000 THINGS, SO LONG AS YOU CAN BEGIN 2429 01:31:59,000 --> 01:32:03,280 TO COPY THEM, THEN EVERYTHING 2430 01:32:03,280 --> 01:32:03,520 CHANGES. 2431 01:32:03,520 --> 01:32:05,360 THAT'S WHEN LIFE BECOMES LIVING, 2432 01:32:05,360 --> 01:32:07,440 TO MY MIND. 2433 01:32:07,440 --> 01:32:09,400 BEFORE THAT IS PREBITE IK 2434 01:32:09,400 --> 01:32:09,720 CHEMISTRY. 2435 01:32:09,720 --> 01:32:11,360 >> IT BECOMES AN RNA WORLD FROM 2436 01:32:11,360 --> 01:32:12,920 THE BEGINNING AT THAT POINT. 2437 01:32:12,920 --> 01:32:15,160 >> BUT IT'S AN RNA WORLD INSIDE 2438 01:32:15,160 --> 01:32:16,160 GROWING PROTO CELLS CAPABLE OF 2439 01:32:16,160 --> 01:32:18,280 DOING ALL THE METABOLIC 2440 01:32:18,280 --> 01:32:19,080 CHEMISTRY THAT OTHER CELLS CAN 2441 01:32:19,080 --> 01:32:19,880 DO. 2442 01:32:19,880 --> 01:32:49,160 THAT 2443 01:32:49,160 --> 01:32:49,920 >> -- HYDROTHERMAL VENT. 2444 01:32:49,920 --> 01:32:52,560 WHY ARE THEY ALKALINE AND NOT 2445 01:32:52,560 --> 01:32:53,760 NEUTRAL OR ACYTIC? 2446 01:32:53,760 --> 01:32:55,720 >> WELL, IT'S BASICALLY A 2447 01:32:55,720 --> 01:32:58,120 REACTION BETWEEN THE ROCK AND 2448 01:32:58,120 --> 01:33:00,200 THE WATER BETWEEN OLIVENE WHICH 2449 01:33:00,200 --> 01:33:07,640 IS RICH IN THER ACYAIN, SOME OF 2450 01:33:07,640 --> 01:33:09,800 THOSE HOE DROX I'D IONS ARE SIM 2451 01:33:09,800 --> 01:33:11,280 SPLI BEING RELEASED INTO 2452 01:33:11,280 --> 01:33:12,040 SOLUTION. 2453 01:33:12,040 --> 01:33:13,880 SO AND THAT'S WHERE THE HYDROGEN 2454 01:33:13,880 --> 01:33:14,880 IS COMING FROM, THE ELECTRONS 2455 01:33:14,880 --> 01:33:17,360 ARE COMING FROM THE ION AS IT'S 2456 01:33:17,360 --> 01:33:18,640 BEING OXIDIZED AND THE WATER IS 2457 01:33:18,640 --> 01:33:21,080 BEING SPLIT INTO HYDROXIDE IONS 2458 01:33:21,080 --> 01:33:21,960 AND HYDROGEN IN EFFECT. 2459 01:33:21,960 --> 01:33:24,360 SO THAT'S WHY IT'S ALKALINE. 2460 01:33:24,360 --> 01:33:27,880 AND IT HAPPENS ON ANY WET ROCKY 2461 01:33:27,880 --> 01:33:29,280 PLANET, THEY'RE ALWAYS ALKALINE. 2462 01:33:29,280 --> 01:33:30,280 IT'S THE ONLY SYSTEM THAT WE 2463 01:33:30,280 --> 01:33:32,360 KNOW OF, REALLY, THAT GENERATES 2464 01:33:32,360 --> 01:33:33,120 ALKALINE FLUIDS. 2465 01:33:33,120 --> 01:33:35,200 >> SO DO YOU THINK THERE ARE 2466 01:33:35,200 --> 01:33:39,400 SIMILAR VENTS ON OTHER BODIES IN 2467 01:33:39,400 --> 01:33:39,840 THE HEAVENS? 2468 01:33:39,840 --> 01:33:41,200 >> I THINK ALL OF THEM PROBABLY. 2469 01:33:41,200 --> 01:33:43,960 I WOULD SAY ANY WET ROCKY PLANET 2470 01:33:43,960 --> 01:33:45,560 WILL HAVE THESE VENT SYSTEMS ON, 2471 01:33:45,560 --> 01:33:47,000 AND THAT'S ONE OF THE PLEASURES 2472 01:33:47,000 --> 01:33:52,560 OF THESE IDEAS, IS THAT IT MAKES 2473 01:33:52,560 --> 01:33:54,000 LIFE COMPLETELY UBIQUITOUS. 2474 01:33:54,000 --> 01:33:55,160 EXCEPT THEN AS JENNIFER WAS 2475 01:33:55,160 --> 01:33:57,080 SAYING, WE HAVE THIS 2 BILLION 2476 01:33:57,080 --> 01:33:58,360 YEAR GAP BEFORE WE SEE COMPLEX 2477 01:33:58,360 --> 01:34:01,600 LIFE, SO IF WE FIND LIFE 2478 01:34:01,600 --> 01:34:03,320 SOMEWHERE ELSE IN THE UNIVERSE, 2479 01:34:03,320 --> 01:34:04,600 THE CHANCES ARE, IT'S GOING TO 2480 01:34:04,600 --> 01:34:06,760 BE BACTERIA, AND MOST PEOPLE 2481 01:34:06,760 --> 01:34:09,000 WON'T BE VERY EXCITED ABOUT IT, 2482 01:34:09,000 --> 01:34:10,880 YOU NEED THE KIND OF PROCESSES 2483 01:34:10,880 --> 01:34:13,040 THAT JENNIFER WAS TALKING ABOUT 2484 01:34:13,040 --> 01:34:15,920 TO GO FROM BACTERIA OR ARCHAEA 2485 01:34:15,920 --> 01:34:16,440 TO COMPLEXITY. 2486 01:34:16,440 --> 01:34:18,280 CAN I ASK YOU A QUESTION, 2487 01:34:18,280 --> 01:34:20,200 JENNIFER, BECAUSE I'M CURIOUS TO 2488 01:34:20,200 --> 01:34:22,480 KNOW HOW WHAT'S THE ENERGY COSTS 2489 01:34:22,480 --> 01:34:25,080 OF HAVING THESE PHASED 2490 01:34:25,080 --> 01:34:26,320 TRANSITIONS IN MEMBRANES AND 2491 01:34:26,320 --> 01:34:32,080 BEING ABLE TO -- ALL THIS 2492 01:34:32,080 --> 01:34:33,200 DYNAMISM YOU'RE TALKING ABOUT, 2493 01:34:33,200 --> 01:34:34,640 IS IT TREMENDOUSLY COSTLY? 2494 01:34:34,640 --> 01:34:36,280 >> THE PHASED TRANSITIONS 2495 01:34:36,280 --> 01:34:39,000 REQUIRE NO ENERGY. 2496 01:34:39,000 --> 01:34:42,760 YOU DON'T HAVE AN ENERGY INPUT 2497 01:34:42,760 --> 01:34:45,240 FROM AN EXOGENOUS SOURCE. 2498 01:34:45,240 --> 01:34:46,320 >> YOU NEED TO MAKE THE 2499 01:34:46,320 --> 01:34:49,120 MEMBRANES THEMSELVES -- 2500 01:34:49,120 --> 01:34:51,360 >> THE MEMBRANES THEMSELVES WILL 2501 01:34:51,360 --> 01:34:53,080 SPONTANEOUSLY MOVE -- PREFER 2502 01:34:53,080 --> 01:34:57,280 BEING IN, YOU KNOW, A -- COME 2503 01:34:57,280 --> 01:34:59,640 TOGETHER IF THERE'S CHOLESTEROL 2504 01:34:59,640 --> 01:35:02,760 AND SPHINGOLIPIDS, FOR INSTANCE. 2505 01:35:02,760 --> 01:35:04,280 AND THE IDEA IS THE INTRODUCTION 2506 01:35:04,280 --> 01:35:08,640 OF THE PROTEINS INTO THESE 2507 01:35:08,640 --> 01:35:09,520 BILAYERS WILL -- PROTEINS WILL 2508 01:35:09,520 --> 01:35:11,280 PREFER BEING IN THE THICKER 2509 01:35:11,280 --> 01:35:12,600 BILAYER FROM THE SINGLE LIPIDS 2510 01:35:12,600 --> 01:35:17,400 AND THE CHOLESTEROL OR THE 2511 01:35:17,400 --> 01:35:20,680 STIFFER VERSUS MORE FLUID LIPID 2512 01:35:20,680 --> 01:35:21,840 ENVIRONMENT, AND THAT'S HOW YOU 2513 01:35:21,840 --> 01:35:25,440 BEGIN TO SORT PROTEINS IN A 2514 01:35:25,440 --> 01:35:26,240 BILAYER. 2515 01:35:26,240 --> 01:35:27,640 ONCE YOU START SORTING PROTEINS 2516 01:35:27,640 --> 01:35:30,000 IN A BILAYER, YOU CAN START 2517 01:35:30,000 --> 01:35:34,080 DOING VERY INTERESTING SORT OF 2518 01:35:34,080 --> 01:35:34,680 FURTHER RECRUITMENTS OF THINGS 2519 01:35:34,680 --> 01:35:37,880 IN THE CYTOPLASM TO BUILD 2520 01:35:37,880 --> 01:35:39,120 CYTOSKELETON, TO CREATE A 2521 01:35:39,120 --> 01:35:40,240 VESICLE THAT CAN MOVE FROM ONE 2522 01:35:40,240 --> 01:35:48,440 PLACE TO ANOTHER. 2523 01:35:48,440 --> 01:35:50,400 I SEE IT AS -- ONCE YOU REALIZE 2524 01:35:50,400 --> 01:35:52,120 THAT THE COMPLEXITY OF THESE 2525 01:35:52,120 --> 01:35:54,000 LIPIDS IS NOT PRESENT IN THESE 2526 01:35:54,000 --> 01:35:56,280 ARCHAEA AND BACTERIA, YOU START 2527 01:35:56,280 --> 01:35:59,360 TO UNDERSTAND WHY THEY CAN'T DO 2528 01:35:59,360 --> 01:35:59,720 INTERCELLULAR -- 2529 01:35:59,720 --> 01:36:01,440 >> IF THEY WERE PRESENT IN 2530 01:36:01,440 --> 01:36:02,280 BACTERIA AND ARCHAEA, DO YOU 2531 01:36:02,280 --> 01:36:03,640 THINK THAT THAT WOULD ALLOW 2532 01:36:03,640 --> 01:36:07,760 BACTERIA AND ARCHAEA TO BECOME 2533 01:36:07,760 --> 01:36:09,200 LARGER OR ARE THEY STILL 2534 01:36:09,200 --> 01:36:10,920 EFFECTIVELY STYMIED BY THE ISSUE 2535 01:36:10,920 --> 01:36:12,440 WITH MITOCHONDRIA AND THE 2536 01:36:12,440 --> 01:36:15,080 ENERGETICS OF IT, AND SO BECAUSE 2537 01:36:15,080 --> 01:36:18,400 EUKARYOTES CAN BECOME LARGER, 2538 01:36:18,400 --> 01:36:20,960 THEY NOW NEED MORE MEMBRANES IN 2539 01:36:20,960 --> 01:36:23,040 EFFECT, AND THEN CAN DO MORE 2540 01:36:23,040 --> 01:36:27,280 SOPHISTICATED THINGS WITH THEM? 2541 01:36:27,280 --> 01:36:30,120 SO I'M WOULD WONDERING IF YOU'RE 2542 01:36:30,120 --> 01:36:32,080 SEEING THE CHEMISTRY OF THE 2543 01:36:32,080 --> 01:36:33,440 SINGLE LIPIDS BEYOND BACTERIA OR 2544 01:36:33,440 --> 01:36:34,640 THEY HAD NO NEED FOR IT BECAUSE 2545 01:36:34,640 --> 01:36:35,760 THEY NEVER COULD EXPAND -- 2546 01:36:35,760 --> 01:36:38,920 >> I THINK THEY HAD NO NEED FOR 2547 01:36:38,920 --> 01:36:40,080 IT, BECAUSE I LIKE THE ARGUMENT 2548 01:36:40,080 --> 01:36:46,000 THAT YOU MAKE IN TERMS OF THE 2549 01:36:46,000 --> 01:36:49,680 GENES THAT ARE CODING FOR THESE 2550 01:36:49,680 --> 01:36:50,520 ELECTRON TRANSPORT COMPONENTS 2551 01:36:50,520 --> 01:36:52,040 NEED TO BE -- THEY NEED TO BE -- 2552 01:36:52,040 --> 01:36:55,200 THEY'VE GOT TO BE COUPLED TO THE 2553 01:36:55,200 --> 01:36:58,160 EXPRESSION OF THE PROTEINS. 2554 01:36:58,160 --> 01:36:59,840 THAT JUST DOESN'T -- I MEAN, 2555 01:36:59,840 --> 01:37:01,680 BECAUSE BACTERIA AND ARCHAEA 2556 01:37:01,680 --> 01:37:06,200 BOTH HAVE THOSE ELECTRON 2557 01:37:06,200 --> 01:37:09,000 TRANSPORT SYSTEM ON THEIR OUTER 2558 01:37:09,000 --> 01:37:10,040 MEMBRANES, THEY'RE BEHOLDEN TO A 2559 01:37:10,040 --> 01:37:11,320 SMALL SIZE. 2560 01:37:11,320 --> 01:37:12,640 BUT THE EUKARYOTE DOESN'T HAVE 2561 01:37:12,640 --> 01:37:14,360 THAT ON ITS PLASMA MEMBRANE. 2562 01:37:14,360 --> 01:37:17,560 IT GOT ENERGY PACKETS FOR DOING 2563 01:37:17,560 --> 01:37:17,880 ALL THAT. 2564 01:37:17,880 --> 01:37:22,600 WHICH IS JUST AN AMAZING, COOL 2565 01:37:22,600 --> 01:37:27,320 WAY TO DEAL WITH THE PROBLEM. 2566 01:37:27,320 --> 01:37:28,720 >> SO IN TERMS OF WHERE ALL 2567 01:37:28,720 --> 01:37:30,400 THESE MEMBRANE SYSTEMS CAME 2568 01:37:30,400 --> 01:37:31,840 FROM, ORIGINALLY, THERE'S SOME 2569 01:37:31,840 --> 01:37:35,240 LOVELY IDEAS ABOUT THE OUTER 2570 01:37:35,240 --> 01:37:37,880 MEMBRANE VESICLES, BUDDING FROM 2571 01:37:37,880 --> 01:37:38,920 BACTERIA AND ARCHAEA AS WELL IS 2572 01:37:38,920 --> 01:37:41,040 QUITE A COMMON PROCESS. 2573 01:37:41,040 --> 01:37:48,560 BUT IF YOU'RE DOING THAT INSIDE 2574 01:37:48,560 --> 01:37:50,760 A PROKARYOTIC CELL THEN YOU'RE 2575 01:37:50,760 --> 01:37:52,720 EFFECTIVELY PRODUCING AT LEAST 2576 01:37:52,720 --> 01:37:54,240 BAD MEMBRANE SYSTEMS, YOU'RE 2577 01:37:54,240 --> 01:37:55,440 PRODUCING VESICLES INSIDE CELLS 2578 01:37:55,440 --> 01:37:57,080 THAT ARE GOING TO FUSE WITH EACH 2579 01:37:57,080 --> 01:37:58,600 OTHER, ARE GOING TO DO THINGS. 2580 01:37:58,600 --> 01:37:59,840 IS PART OF THE PROBLEM HOW DO 2581 01:37:59,840 --> 01:38:03,000 YOU STOP IT BECOMING A HORRIBLE 2582 01:38:03,000 --> 01:38:03,200 MESS? 2583 01:38:03,200 --> 01:38:13,400 >> YEAH. 2584 01:38:13,400 --> 01:38:15,280 YOU'VE GOT TO SHIFT OVER, THE 2585 01:38:15,280 --> 01:38:21,400 ARCHAEA LIPID, BASE KRI BASICALLY YOU GOT 2586 01:38:21,400 --> 01:38:23,080 RID OF IT SO ALL THE 2587 01:38:23,080 --> 01:38:24,080 PHOSPHOLIPIDS ARE ESTER LINKED 2588 01:38:24,080 --> 01:38:24,920 SO THAT'S ONE SYSTEM. 2589 01:38:24,920 --> 01:38:26,680 AND THAT'S A HUGE ARGUMENT 2590 01:38:26,680 --> 01:38:28,440 AGAINST THE CLASSIC MODEL, YOU 2591 01:38:28,440 --> 01:38:35,760 KNOW, THE STEP WISE MODEL FOR 2592 01:38:35,760 --> 01:38:39,360 THE ORIGIN OF EU EUKARYOTES, IT'S 2593 01:38:39,360 --> 01:38:41,400 GOING TO HAVE THE ARCHAEA LIPIDS 2594 01:38:41,400 --> 01:38:42,880 THAT ARE MAKING ALL OF THOSE 2595 01:38:42,880 --> 01:38:44,520 INTERNAL MEMBRANES, AND -- 2596 01:38:44,520 --> 01:38:45,120 >> YES. 2597 01:38:45,120 --> 01:38:47,440 >> NONE OF THE MODERN-DAY 2598 01:38:47,440 --> 01:38:50,080 EUKARYOTES HAVE THE ETHER LINKED 2599 01:38:50,080 --> 01:38:50,440 LIPIDS. 2600 01:38:50,440 --> 01:38:53,360 >> I THINK THERE ARE SOME ETHER 2601 01:38:53,360 --> 01:38:54,680 LINKED LIPIDS IN EU CARE YOTS, 2602 01:38:54,680 --> 01:38:56,280 AREN'T THERE, I THINK, 2603 01:38:56,280 --> 01:38:58,600 OCCASIONALLY, BUT THEY TEND TO 2604 01:38:58,600 --> 01:38:59,280 BE -- 2605 01:38:59,280 --> 01:39:03,280 >> THEY'RE VERY RARE. 2606 01:39:03,280 --> 01:39:08,320 >> RIGHT. 2607 01:39:08,320 --> 01:39:09,880 THEY'RE PART OF A PATHWAY IN 2608 01:39:09,880 --> 01:39:14,440 CERTAIN TYPES OF BIG LIPIDS, 2609 01:39:14,440 --> 01:39:16,640 MYELIN, FOR INSTANCE. 2610 01:39:16,640 --> 01:39:25,320 BUT I WANTED TO ASK YOU ABOUT IF 2611 01:39:25,320 --> 01:39:26,560 YOU WERE GOING TO LOOK FOR A 2612 01:39:26,560 --> 01:39:27,960 SIGNATURE FOR LIFE ON ANOTHER 2613 01:39:27,960 --> 01:39:32,120 PLANET, NOW WE HAVE THE BIG WEB 2614 01:39:32,120 --> 01:39:32,920 TELESCOPE, WHAT IS THAT YOU 2615 01:39:32,920 --> 01:39:34,640 WOULD LOOK FOR? 2616 01:39:34,640 --> 01:39:36,280 I MEAN, I AGREE THE 2617 01:39:36,280 --> 01:39:38,280 EUKARYOTIC -- GETTING TO A 2618 01:39:38,280 --> 01:39:39,280 EUKARYOTIC STATE IS GOING TO 2619 01:39:39,280 --> 01:39:40,080 TAKE SOME TIME. 2620 01:39:40,080 --> 01:39:43,480 THERE'S A LOT OF ISSUES THAT ARE 2621 01:39:43,480 --> 01:39:45,160 INVOLVED, BUT IT SEEMS LIKE LIFE 2622 01:39:45,160 --> 01:39:49,760 COMES PRETTY QUICK IN TERMS OF 2623 01:39:49,760 --> 01:39:51,000 PROKARYOTIC METABOLIC -- 2624 01:39:51,000 --> 01:39:54,680 >> SEEMS THAT WAY TO ME, YES. 2625 01:39:54,680 --> 01:39:59,720 I THINK I WOULD OFFER -- YOU CAN 2626 01:39:59,720 --> 01:40:03,960 GET SOME LEVEL OF -- FROM 2627 01:40:03,960 --> 01:40:06,160 MINERAL CATALYSIS OR VARIOUS 2628 01:40:06,160 --> 01:40:10,280 PROCESSES, BUT AS SOON AS YOU'VE 2629 01:40:10,280 --> 01:40:11,280 GOTTEN 2630 01:40:11,280 --> 01:40:18,080 GOT ENZYMES, EU MORE OR LESS OWE 2631 01:40:18,080 --> 01:40:21,080 OBLIGED -- WHEN WE TALK ABOUT 2632 01:40:21,080 --> 01:40:24,200 KIE RALLITY -- IT WAS ONE OR THE 2633 01:40:24,200 --> 01:40:24,480 OTHER. 2634 01:40:24,480 --> 01:40:25,680 BUT THE LIPIDS ARE REALLY 2635 01:40:25,680 --> 01:40:28,560 INTERESTING HERE, BECAUSE THE 2636 01:40:28,560 --> 01:40:30,280 PHOSPHATE HEAD GROUPS ARE THE 2637 01:40:30,280 --> 01:40:33,960 OPPOSITE AND OPPOSING CHIRALITY 2638 01:40:33,960 --> 01:40:34,440 IN THE ARCHAEA. 2639 01:40:34,440 --> 01:40:37,840 SO THE THREE LARGE GROUPS OF 2640 01:40:37,840 --> 01:40:40,560 MOLECULES THAT HAVE THIS 2641 01:40:40,560 --> 01:40:42,080 CHIRALITY, TWO OF THEM ARE 2642 01:40:42,080 --> 01:40:44,720 UNIVERSAL BETWEEN BACTERIA AND 2643 01:40:44,720 --> 01:40:45,880 ARCHAEA, ONE OF THEM IS 2644 01:40:45,880 --> 01:40:49,000 SHOWING -- WHICH TO MY MIND, 2645 01:40:49,000 --> 01:40:50,440 IT'S ABOUT ENZYMES, NOT ABOUT 2646 01:40:50,440 --> 01:40:52,600 SOME STRANGE PHYSICAL PROCESS, 2647 01:40:52,600 --> 01:40:54,240 IT'S JUST ABOUT ARE YOU 2648 01:40:54,240 --> 01:40:55,440 APPROACHING IT FROM ABOVE OR 2649 01:40:55,440 --> 01:40:56,960 BELOW AS AN ENZYME, AND THEN 2650 01:40:56,960 --> 01:40:59,880 YOU'LL GET THE OPPOSITE 2651 01:40:59,880 --> 01:41:00,320 CHIRALITY. 2652 01:41:00,320 --> 01:41:04,160 SO I THINK OF CHIRALITY AS A 2653 01:41:04,160 --> 01:41:07,680 PRODUCT OF BIOLOGY, AND THAT 2654 01:41:07,680 --> 01:41:13,440 MEANS THAT IF WE SEE IN ANY 2655 01:41:13,440 --> 01:41:16,760 PLANETARY ATMOSPHERE VERY STRONG 2656 01:41:16,760 --> 01:41:17,520 CHIRALITY, THEN THAT WOULD BE A 2657 01:41:17,520 --> 01:41:18,480 SIGN OF LIFE. 2658 01:41:18,480 --> 01:41:21,040 WOULD WE BE LOOKING FOR NIDH OR 2659 01:41:21,040 --> 01:41:21,840 ATP, I CAN'T IMAGINE THAT WE 2660 01:41:21,840 --> 01:41:23,600 WOULD BE. 2661 01:41:23,600 --> 01:41:25,240 AND IF YOU'RE LOOKING FOR THINGS 2662 01:41:25,240 --> 01:41:27,680 LIKE ACETATE OR PYRUVATE, THEN 2663 01:41:27,680 --> 01:41:29,080 THAT'S SOMETHING THAT A 2664 01:41:29,080 --> 01:41:30,160 HYDROTHERMAL SYSTEM CAN PRODUCE 2665 01:41:30,160 --> 01:41:31,120 ANYWAY, SO IT'S REALLY HARD TO 2666 01:41:31,120 --> 01:41:32,280 KNOW WHERE YOU DRAW THE LINE, 2667 01:41:32,280 --> 01:41:35,280 AND I THINK CHIRALITY IS WHERE I 2668 01:41:35,280 --> 01:41:35,680 WOULD DRAW IT. 2669 01:41:35,680 --> 01:41:37,360 >> DO YOU KNOW WHETHER ANYBODY 2670 01:41:37,360 --> 01:41:40,080 HAS DONE ANY CHIRALITY 2671 01:41:40,080 --> 01:41:41,960 MEASUREMENTS IN THESE METEORITES 2672 01:41:41,960 --> 01:41:44,280 THAT HAVE COME FROM MARS OR -- 2673 01:41:44,280 --> 01:41:45,520 >> YOU KNOW, I DON'T. 2674 01:41:45,520 --> 01:41:47,520 I ASSUME THEY HAVE. 2675 01:41:47,520 --> 01:41:49,360 I'D BE AMAZED IF THEY HADN'T. 2676 01:41:49,360 --> 01:41:50,600 IT'S NOT SOMETHING THAT I FOLLOW 2677 01:41:50,600 --> 01:41:55,280 VERY CLOSELY. 2678 01:41:55,280 --> 01:41:58,080 I'M SURE IF THEY FOUND THEY 2679 01:41:58,080 --> 01:42:01,360 REALLY CHIRAL, I'M GUESSING NOT. 2680 01:42:01,360 --> 01:42:02,800 >> LET ME POSE A QUESTION THAT 2681 01:42:02,800 --> 01:42:03,680 EITHER OF YOU MAY ANSWER. 2682 01:42:03,680 --> 01:42:07,840 THIS IS FROM PATTI. 2683 01:42:07,840 --> 01:42:09,480 IT SAYS SOME BACTERIA THAT HAVE 2684 01:42:09,480 --> 01:42:14,480 AN OBLIGATORY COEXISTENCE WITH 2685 01:42:14,480 --> 01:42:17,400 THE EUKARYOTE ACIDIC HOST HAVE 2686 01:42:17,400 --> 01:42:20,800 SMALL GENOMES, MINIMA LIST 2687 01:42:20,800 --> 01:42:22,760 METABOLISMS, SCAVAGED FATTY 2688 01:42:22,760 --> 01:42:25,400 ACIDS FROM THE HOSTS AND HAVE 2689 01:42:25,400 --> 01:42:28,360 MEMBRANES THAT CONTAIN EUKARYOTE 2690 01:42:28,360 --> 01:42:30,000 ACYTIC LIPIDS, WOULD YOU EXPECT 2691 01:42:30,000 --> 01:42:33,720 THEM TO HAVE A MORE COMPLEX 2692 01:42:33,720 --> 01:42:37,200 CYTOSKELETAL STRUCTURE? 2693 01:42:37,200 --> 01:42:38,000 >> INTERESTING QUESTION. 2694 01:42:38,000 --> 01:42:39,560 JENNIFER, DO YOU WANT TO HAVE A 2695 01:42:39,560 --> 01:42:39,840 GO FIRST? 2696 01:42:39,840 --> 01:42:42,880 >> WELL, IF THEY HAVE A SMALL 2697 01:42:42,880 --> 01:42:49,680 GENOME, PROBABLY NOT. 2698 01:42:49,680 --> 01:42:52,560 I'D LIKE TO KNOW MORE ABOUT THAT 2699 01:42:52,560 --> 01:42:55,600 BACTERIA IN TERMS OF -- WHEN YOU 2700 01:42:55,600 --> 01:42:57,880 SAY IT HAS EUKARYOTIC LIPIDS, 2701 01:42:57,880 --> 01:43:00,400 DOES IT HAVE STEROLS? 2702 01:43:00,400 --> 01:43:02,080 I WOULD ARGUE THAT IF IT'S 2703 01:43:02,080 --> 01:43:03,800 NOT -- BASED ON THE PROPOSAL 2704 01:43:03,800 --> 01:43:05,880 THAT I MADE, WHICH THERE'S NO 2705 01:43:05,880 --> 01:43:07,560 EVIDENCE FOR, BUT IT JUST THE 2706 01:43:07,560 --> 01:43:12,000 WAY I LIKE TO THINK ABOUT IT, IF 2707 01:43:12,000 --> 01:43:16,440 THAT BACTERIA DOESN'T HAVE THESE 2708 01:43:16,440 --> 01:43:18,760 COMPLEX LIPIDS THAT CAN PHASE 2709 01:43:18,760 --> 01:43:19,600 PARTITION, YOU'RE TO THE GOING 2710 01:43:19,600 --> 01:43:24,000 TO GET ANY COMPLICATED 2711 01:43:24,000 --> 01:43:24,600 CYTOSKELETON THAT'S GOING TO 2712 01:43:24,600 --> 01:43:25,960 COUPLE TO THAT MEMBRANE AND 2713 01:43:25,960 --> 01:43:26,480 DRIVE -- 2714 01:43:26,480 --> 01:43:27,400 >> THE QUESTION IS IF IT'S 2715 01:43:27,400 --> 01:43:29,280 STEALING ITS LIPIDS FROM THE 2716 01:43:29,280 --> 01:43:30,760 EUKARYOTIC HOST CELL, THEN 2717 01:43:30,760 --> 01:43:31,800 EFFECTIVELY IT'S GOT STOLEN 2718 01:43:31,800 --> 01:43:35,320 COMPLEX LIPIDS, WOULD IT THEN -- 2719 01:43:35,320 --> 01:43:36,680 >> NO, THAT'S A GOOD POINT. 2720 01:43:36,680 --> 01:43:39,320 THAT'S A VERY GOOD POINT. 2721 01:43:39,320 --> 01:43:43,960 YEAH. 2722 01:43:43,960 --> 01:43:45,200 I THINK THE ENERGETIC 2723 01:43:45,200 --> 01:43:46,480 CONSTRAINTS WOULD BE THE PROBLEM 2724 01:43:46,480 --> 01:43:48,360 FOR IT THERE, IT EFFECTIVELY 2725 01:43:48,360 --> 01:43:50,760 WOULD HAVE THE POTENTIAL TO DO 2726 01:43:50,760 --> 01:43:51,760 THESE SOPHISTICATED THINGS WITH 2727 01:43:51,760 --> 01:43:54,440 THESE LIPIDS, BUT I'VE THOUGHT 2728 01:43:54,440 --> 01:43:56,280 FOR QUITE A LONG TIME ABOUT WHY 2729 01:43:56,280 --> 01:43:58,120 YOU COULDN'T JUST USE A 2730 01:43:58,120 --> 01:44:01,280 BACTERIAL PLASMID, FOR EXAMPLE. 2731 01:44:01,280 --> 01:44:05,440 INSTEAD OF -- SO I WOULD SEE 2732 01:44:05,440 --> 01:44:07,280 MITOCHONDRIAL DNA MORE OR LESS 2733 01:44:07,280 --> 01:44:09,280 LIKE PLASMID SITTING INSIDE THE 2734 01:44:09,280 --> 01:44:09,600 MITOCHONDRIA. 2735 01:44:09,600 --> 01:44:11,240 TAKE OUT THE MITOCHONDRIAL DNA 2736 01:44:11,240 --> 01:44:12,960 AND STICK IT NEXT TO THE PLASMA 2737 01:44:12,960 --> 01:44:14,520 MEMBRANE AND THEN SCALE UP A 2738 01:44:14,520 --> 01:44:16,480 BACTERIAL CELL TO A EUKARYOTIC 2739 01:44:16,480 --> 01:44:18,680 SIZE AND LET'S PUT TENS OF 2740 01:44:18,680 --> 01:44:19,680 THOUSANDS OF COPIES OF THIS 2741 01:44:19,680 --> 01:44:20,800 GENOME RIGHT NEXT TO THE 2742 01:44:20,800 --> 01:44:21,800 MEMBRANE, WHY IS IT NOT GOING TO 2743 01:44:21,800 --> 01:44:24,080 WORK? 2744 01:44:24,080 --> 01:44:25,520 BECAUSE WE NEVER SEE THAT, 2745 01:44:25,520 --> 01:44:25,760 REALLY. 2746 01:44:25,760 --> 01:44:26,440 >> RIGHT, RIGHT. 2747 01:44:26,440 --> 01:44:29,560 >> I THINK ONE OF THE REASONS IT 2748 01:44:29,560 --> 01:44:35,120 DOESN'T WORK IS THAT THIS KIND 2749 01:44:35,120 --> 01:44:36,040 OF -- THERE'S VERY LITTLE 2750 01:44:36,040 --> 01:44:38,080 ADVANTAGE FOR BACTERIUM SIMPLY 2751 01:44:38,080 --> 01:44:40,680 BEING BIGGER FOR ITS OWN SAKE. 2752 01:44:40,680 --> 01:44:42,680 IT JUST TAKES LONGER TO 2753 01:44:42,680 --> 01:44:44,000 REPLICATE ITSELF THEN. 2754 01:44:44,000 --> 01:44:46,240 SO IF YOU THINK, WELL, OKAY, IF 2755 01:44:46,240 --> 01:44:48,120 YOU MAKE YOURSELF TWEIST AS BIG 2756 01:44:48,120 --> 01:44:49,360 AND YOU'RE A STREAMLINE SHAPE 2757 01:44:49,360 --> 01:44:50,880 AND SO ON, THEN YOU CAN MAKE 2758 01:44:50,880 --> 01:44:53,960 TWICE AS MUCH ATP, SO YOU HAVE 2759 01:44:53,960 --> 01:44:56,760 AN ADVANTAGE, YOU'VE GOT MORE 2760 01:44:56,760 --> 01:44:57,880 ATP, BUT YOU'VE TAKEN TWICE AS 2761 01:44:57,880 --> 01:44:59,320 LONG TO REPLICATE YOURSELF AND 2762 01:44:59,320 --> 01:45:02,800 SO YOU'RE GOING TO LOSE OUT TO 2763 01:45:02,800 --> 01:45:04,320 SMALLER BACTERIA, SO THE 2764 01:45:04,320 --> 01:45:05,520 SELECTION PRESSURE ON BACTERIA 2765 01:45:05,520 --> 01:45:07,160 IS PRETTY MUCH ALWAYS GOING TO 2766 01:45:07,160 --> 01:45:07,840 BE -- TO REMAIN SMALL. 2767 01:45:07,840 --> 01:45:09,040 BUT THE OTHER REASON I DON'T 2768 01:45:09,040 --> 01:45:10,640 THINK IT'S GOING TO WORK IS THAT 2769 01:45:10,640 --> 01:45:13,440 IF YOU'VE GOT HUNDREDS OF COPIES 2770 01:45:13,440 --> 01:45:16,040 OF A GENOME AND THEY'RE ALL 2771 01:45:16,040 --> 01:45:17,880 KRNTING TO A COMBINED PHENOTYPE, 2772 01:45:17,880 --> 01:45:19,720 WHICH IS LET'S SAY THE MEMBRANE 2773 01:45:19,720 --> 01:45:22,120 POTENTIAL ON THE PLASMA 2774 01:45:22,120 --> 01:45:25,320 MEMBRANE, EVEN IF IT'S 2775 01:45:25,320 --> 01:45:26,800 INVAGINATED, THEN SELECTION 2776 01:45:26,800 --> 01:45:28,080 CAN'T SEE MUTATIONS IN ANY ONE 2777 01:45:28,080 --> 01:45:32,440 OF THOSE GENOMES PAUSE THREAR 2778 01:45:32,440 --> 01:45:34,760 ALL BECAUSE THEY'RE 2779 01:45:34,760 --> 01:45:37,080 ALL CONTRIBUTING TO A COMMON 2780 01:45:37,080 --> 01:45:37,480 PHENOTYPE. 2781 01:45:37,480 --> 01:45:39,080 YOU DON'T CHANGE THE MEMBRANE 2782 01:45:39,080 --> 01:45:39,880 POTENTIAL MUCH SO YOU'RE GOING 2783 01:45:39,880 --> 01:45:41,920 TO ACCUMULATE MUTATIONS UNTIL 2784 01:45:41,920 --> 01:45:45,800 YOU HAVE A MU MUTATIONAL MELT DOWN. 2785 01:45:45,800 --> 01:45:52,800 IF YOU HAVE A SICKLE MY TOE CON 2786 01:45:52,800 --> 01:45:54,080 MITOCHONDRIA, WHY DO WE HAVE 2787 01:45:54,080 --> 01:45:55,640 INFUSION INTO WHOLE NETWORKS 2788 01:45:55,640 --> 01:45:58,160 WHICH YOU SHOW SEW AMAZINGLY AND 2789 01:45:58,160 --> 01:45:59,240 BEAUTIFULLY BUT YOU HAVE KIND OF 2790 01:45:59,240 --> 01:46:01,840 A LAMINATED NETWORK OF ALL THESE 2791 01:46:01,840 --> 01:46:03,480 MITOCHONDRIA, BUT IF YOU BLOCK 2792 01:46:03,480 --> 01:46:06,760 THEM -- EVERYTHING DEGENERATES 2793 01:46:06,760 --> 01:46:07,320 AFTER SOME TIME. 2794 01:46:07,320 --> 01:46:17,080 SO WHY IS MITOCHONDRIAL FISSION 2795 01:46:17,080 --> 01:46:17,680 SO IMPORTANT. 2796 01:46:17,680 --> 01:46:20,080 WHAT YOU HAVE THEN IS A GENOTYPE 2797 01:46:20,080 --> 01:46:21,160 PHENOTYPE RELATIONSHIP. 2798 01:46:21,160 --> 01:46:25,840 WE HAVE A -- IF YOU'VE GOT 2799 01:46:25,840 --> 01:46:26,960 MUTATIONS IN THAT GENOME, THEN 2800 01:46:26,960 --> 01:46:28,280 IT'S NOT GOING TO BE ABLE TO 2801 01:46:28,280 --> 01:46:29,440 MAINTAIN A GOOD MEMBRANE 2802 01:46:29,440 --> 01:46:31,320 POTENTIAL AND IT CAN BE TARGETED 2803 01:46:31,320 --> 01:46:35,400 BY AUTOPHAGY AND BROKEN DOWN AND 2804 01:46:35,400 --> 01:46:38,360 SO BY FISSIONING, YOU 2805 01:46:38,360 --> 01:46:39,480 RE-ESTABLISH A CAUSAL 2806 01:46:39,480 --> 01:46:40,640 RELATIONSHIP BETWEEN THE 2807 01:46:40,640 --> 01:46:42,000 PHENOTYPE AND GENOTYPE, YOU CAN 2808 01:46:42,000 --> 01:46:43,880 VECT THINGS 2809 01:46:43,880 --> 01:46:45,600 SELECT THINGS AND DISPOSE OF THE 2810 01:46:45,600 --> 01:46:45,800 JUNK. 2811 01:46:45,800 --> 01:46:47,360 WHEREAS IF YOU HAVE A KIND OF 2812 01:46:47,360 --> 01:46:48,000 COMMON PHENOTYPE, THEN YOU CAN 2813 01:46:48,000 --> 01:46:48,680 NEVER DO THAT. 2814 01:46:48,680 --> 01:46:52,280 SO I THINK THERE'S SEVERAL 2815 01:46:52,280 --> 01:46:53,440 REASONS WHY BACTERIA DON'T WANT 2816 01:46:53,440 --> 01:46:56,520 TO GET THAT BIG. 2817 01:46:56,520 --> 01:46:57,840 >> THERE'S A LOT OF REASONS WHY 2818 01:46:57,840 --> 01:47:00,360 YOU WANT TO USE SMALL UNITS FOR 2819 01:47:00,360 --> 01:47:06,960 THAT TYPE OF MITOCHONDRIAL 2820 01:47:06,960 --> 01:47:07,280 EVOLUTION. 2821 01:47:07,280 --> 01:47:10,440 I MEAN, THE MITOCHONDRIAL -- I 2822 01:47:10,440 --> 01:47:13,400 MEAN, WE USE MITOCHONDRIAL DNA 2823 01:47:13,400 --> 01:47:15,320 TO TRACK HUMAN EVOLUTION. 2824 01:47:15,320 --> 01:47:16,640 HUMAN MIGRATION. 2825 01:47:16,640 --> 01:47:20,080 AND IT BECAUSE OF THIS RAPID 2826 01:47:20,080 --> 01:47:25,240 ABILITY TO MUTATE, AND ON A MUCH 2827 01:47:25,240 --> 01:47:27,080 RAPID SCALE THAN WE SEE IN THE 2828 01:47:27,080 --> 01:47:27,320 NUCLEUS. 2829 01:47:27,320 --> 01:47:29,440 >> AND THE SELECTION AS WELL IN 2830 01:47:29,440 --> 01:47:31,440 THE GERMLINE, IN THE FEMALE 2831 01:47:31,440 --> 01:47:33,080 GERMLINE, YOU HAVE THIS 2832 01:47:33,080 --> 01:47:37,360 COMBINATION OF FAST RATES OF 2833 01:47:37,360 --> 01:47:38,560 MUTATION COMBINED WITH SELECTION 2834 01:47:38,560 --> 01:47:39,680 FOR THE ONES THAT WORK, SO 2835 01:47:39,680 --> 01:47:43,160 YOU'RE NOT PRODUCING MANY 2836 01:47:43,160 --> 01:47:45,120 CHILDREN WITH MITOCHONDRIAL 2837 01:47:45,120 --> 01:47:46,000 DISEASES. 2838 01:47:46,000 --> 01:47:47,280 IT HAPPENS, BUT GIVEN THAT IT'S 2839 01:47:47,280 --> 01:47:48,280 MUTATING AT 10 TIMES FASTER THAN 2840 01:47:48,280 --> 01:47:52,240 THE RATE OF THE -- GENES, 2841 01:47:52,240 --> 01:47:53,320 MITOCHONDRIAL DISEASES ARE 2842 01:47:53,320 --> 01:47:59,280 AMAZINGLY RARE. 2843 01:47:59,280 --> 01:48:01,560 >> SO JENNIFER, WE HAVE AN 2844 01:48:01,560 --> 01:48:05,120 INTERESTING QUESTION ABOUT 2845 01:48:05,120 --> 01:48:06,680 PLASMALOGENS, WHICH IN 2846 01:48:06,680 --> 01:48:08,200 EUKARYOTIC CELLS HAVE BOTH AN 2847 01:48:08,200 --> 01:48:10,280 ESTER AND ETHER LINKAGE. 2848 01:48:10,280 --> 01:48:11,680 SO JOSHUA WOULD LIKE TO KNOW, DO 2849 01:48:11,680 --> 01:48:13,000 YOU HAVE ANY IDEAS AS TO THE 2850 01:48:13,000 --> 01:48:17,400 EMERGENCE OR THE IMPORTANCE OF 2851 01:48:17,400 --> 01:48:19,320 PLASMALOGENS IN EUKARYOTIC 2852 01:48:19,320 --> 01:48:23,400 CELLS? 2853 01:48:23,400 --> 01:48:26,640 >> 2854 01:48:26,640 --> 01:48:30,840 >> I KNOW PROXOSOMES ARE DEALING 2855 01:48:30,840 --> 01:48:34,680 WITH THEM, AND SOME OF THESE 2856 01:48:34,680 --> 01:48:36,200 PLASMOLOGENS ARE INVOLVED IN 2857 01:48:36,200 --> 01:48:39,760 MYELINATION OF NERVES. 2858 01:48:39,760 --> 01:48:42,440 IT MIGHT -- I MEAN, THESE F 2859 01:48:42,440 --> 01:48:44,160 ETHER LIPIDS COULD BE VERY -- 2860 01:48:44,160 --> 01:48:48,960 YOU KNOW, MAKE THE MEMBRANE MORE 2861 01:48:48,960 --> 01:48:50,640 RESISTANT TO BEING PERMEABLE. 2862 01:48:50,640 --> 01:48:53,440 I DON'T KNOW. 2863 01:48:53,440 --> 01:48:55,320 BUT IT'S VERY, VERY INTERESTING. 2864 01:48:55,320 --> 01:48:56,120 YEAH. 2865 01:48:56,120 --> 01:48:59,120 >> WHAT DO YOU THINK, NICK? 2866 01:48:59,120 --> 01:49:00,880 >> I DON'T HAVE AN OPINION ON 2867 01:49:00,880 --> 01:49:01,080 THAT. 2868 01:49:01,080 --> 01:49:05,480 I THINK I'M OUT OF MY -- 2869 01:49:05,480 --> 01:49:06,440 >> [INAUDIBLE] 2870 01:49:06,440 --> 01:49:08,680 >> IT'S CONNECTED TO WHAT? 2871 01:49:08,680 --> 01:49:08,880 SORRY? 2872 01:49:08,880 --> 01:49:10,880 >> MYELINATION, NERVE 2873 01:49:10,880 --> 01:49:11,200 MYELINATION. 2874 01:49:11,200 --> 01:49:15,000 >> RIGHT. 2875 01:49:15,000 --> 01:49:15,200 OKAY. 2876 01:49:15,200 --> 01:49:16,800 >> SO WE HAVE A FUNDAMENTAL 2877 01:49:16,800 --> 01:49:19,880 QUESTION FOR BOTH OF YOU. 2878 01:49:19,880 --> 01:49:22,960 COULD EACH OF YOU PLEASE DEFINE 2879 01:49:22,960 --> 01:49:25,640 LIFE? 2880 01:49:25,640 --> 01:49:28,560 >> WELL, I STARTED OUT BY 2881 01:49:28,560 --> 01:49:30,440 REFUSING TO DEFINE LIFE, AND I 2882 01:49:30,440 --> 01:49:34,440 ACTUALLY THINK IT'S THE WRONG 2883 01:49:34,440 --> 01:49:34,720 QUESTION. 2884 01:49:34,720 --> 01:49:36,240 BECAUSE LIFE IS A PROCESS. 2885 01:49:36,240 --> 01:49:38,960 IT'S SOMETHING HAPPENING OVER 2886 01:49:38,960 --> 01:49:40,480 TIME. 2887 01:49:40,480 --> 01:49:43,560 AND SO IS A VIRUS ALIVE? 2888 01:49:43,560 --> 01:49:44,520 MOST BIOLOGISTS WOULD ARGUE 2889 01:49:44,520 --> 01:49:46,600 ABOUT WHETHER A VIRUS IS ALIVE 2890 01:49:46,600 --> 01:49:49,280 OR NOT BECAUSE IT DOESN'T HAVE 2891 01:49:49,280 --> 01:49:50,280 ITS OWN METABOLISM. 2892 01:49:50,280 --> 01:49:52,040 I BASICALLY SEE A VIRUS AS BEING 2893 01:49:52,040 --> 01:49:53,440 ALIVE BECAUSE THEY'RE NASTY 2894 01:49:53,440 --> 01:49:54,840 BASTARDS AND THEY TAKE OVER THE 2895 01:49:54,840 --> 01:49:56,160 METABOLISM OF THE CELLS THAT 2896 01:49:56,160 --> 01:49:58,600 THEY LIVE IN IN VERY 2897 01:49:58,600 --> 01:49:59,120 SOPHISTICATED WAYS. 2898 01:49:59,120 --> 01:50:00,880 THEY EVOLVE, THEY CHANGE, THEY 2899 01:50:00,880 --> 01:50:02,120 MUTATE, THEY DO EVERYTHING TO DO 2900 01:50:02,120 --> 01:50:03,680 WITH LIFE APART FROM METABOLISM, 2901 01:50:03,680 --> 01:50:06,560 AND THEY DON'T NEED THAT. 2902 01:50:06,560 --> 01:50:08,280 BUT THEN WE ARE FAR MORE 2903 01:50:08,280 --> 01:50:09,080 PARASITIC ON OUR ENVIRONMENT 2904 01:50:09,080 --> 01:50:10,360 THAN PLANTS ARE. 2905 01:50:10,360 --> 01:50:14,320 WE NEED TO EAT OTHER THINGS. 2906 01:50:14,320 --> 01:50:16,200 SO IN SOME SENSE, LIKE A VIRUS, 2907 01:50:16,200 --> 01:50:18,280 WE ARE ALSO PARASITIC ON THE 2908 01:50:18,280 --> 01:50:19,440 ENVIRONMENT, AND THEN YOU THINK 2909 01:50:19,440 --> 01:50:22,080 WELL, PLANTS ARE AS WELL IN THE 2910 01:50:22,080 --> 01:50:24,760 SENSE THAT THEY STILL REQUIRE 2911 01:50:24,760 --> 01:50:26,080 CO2 TO FIX IN WATER, THEY'RE NOT 2912 01:50:26,080 --> 01:50:27,840 GOING TO GROW IN A DESERT OR IN 2913 01:50:27,840 --> 01:50:30,120 THE DARK, SO THEY REQUIRE THINGS 2914 01:50:30,120 --> 01:50:31,000 FROM THE ENVIRONMENT TO ENABLE 2915 01:50:31,000 --> 01:50:32,880 THEM TO GROW. 2916 01:50:32,880 --> 01:50:34,280 AND BY THAT DEFINITION, IT'S NOT 2917 01:50:34,280 --> 01:50:35,360 A DEFINITION, BY THAT WAY OF 2918 01:50:35,360 --> 01:50:37,440 SEEING IT, THE VIRUS JUST 2919 01:50:37,440 --> 01:50:38,320 REQUIRES MORE THINGS FROM ITS 2920 01:50:38,320 --> 01:50:39,840 ENVIRONMENT TO BE ABLE TO GROW. 2921 01:50:39,840 --> 01:50:41,680 SO YOU COULD THEN THINK OF LIFE 2922 01:50:41,680 --> 01:50:44,640 AS BEING PARASITIC UPON AN 2923 01:50:44,640 --> 01:50:46,640 ENVIRONMENT, AND BY THAT, THEN 2924 01:50:46,640 --> 01:50:48,480 WHAT ABOUT RETRO ELEMENTS? 2925 01:50:48,480 --> 01:50:50,360 ARE THEY ALIVE? 2926 01:50:50,360 --> 01:50:52,560 BY THAT, THEY TAKE EVEN MORE 2927 01:50:52,560 --> 01:50:53,520 FROM THEIR ENVIRONMENT THAN A 2928 01:50:53,520 --> 01:50:55,840 VIRUS DOES. 2929 01:50:55,840 --> 01:50:56,800 AND IT'S IMPOSSIBLE TO KNOW 2930 01:50:56,800 --> 01:50:59,080 WHERE TO DRAW THE LINE. 2931 01:50:59,080 --> 01:50:59,880 THERE ISN'T A LINE. 2932 01:50:59,880 --> 01:51:03,560 THERE'S JUST SIMPLY DIFFERENT 2933 01:51:03,560 --> 01:51:05,120 FORMS OF PARASITISM ON AN 2934 01:51:05,120 --> 01:51:06,280 ENVIRONMENT, AND IT'S AMAZING IF 2935 01:51:06,280 --> 01:51:07,920 YOU SEE THE WORLD THAT WAY, JUST 2936 01:51:07,920 --> 01:51:08,920 HOW BEAUTIFUL IT ALL TURNS OUT 2937 01:51:08,920 --> 01:51:11,040 TO BE. 2938 01:51:11,040 --> 01:51:15,280 >> WHAT DO THE -- I'M STRUGGLING 2939 01:51:15,280 --> 01:51:15,920 FOR THE WORD. 2940 01:51:15,920 --> 01:51:19,680 I COME UP WITH OFFICIALS BUT -- 2941 01:51:19,680 --> 01:51:21,680 WHAT IS THIS SORT OF 2942 01:51:21,680 --> 01:51:22,600 ORGANIZATIONAL DEFINITION OF 2943 01:51:22,600 --> 01:51:26,880 LIFE THESE DAYS? 2944 01:51:26,880 --> 01:51:30,240 >> I IGNORE IT DELIBERATELY, SO 2945 01:51:30,240 --> 01:51:31,640 I DON'T KNOW. 2946 01:51:31,640 --> 01:51:33,400 >> OKAY. 2947 01:51:33,400 --> 01:51:35,360 WE HAVE AN INTERESTING QUESTION. 2948 01:51:35,360 --> 01:51:39,200 IF THE PROTON -- THE MODE OF 2949 01:51:39,200 --> 01:51:45,280 FORCE IS ONLY ABOUT 200 MILL 2950 01:51:45,280 --> 01:51:45,880 200 MILLIVOLTS, THAT ISN'T A 2951 01:51:45,880 --> 01:51:46,080 LOT. 2952 01:51:46,080 --> 01:51:51,880 >> WELL, IT IS A LOT IF YOU 2953 01:51:51,880 --> 01:51:55,000 THINK ABOUT THE FIELD STRENGTH, 2954 01:51:55,000 --> 01:51:56,040 BECAUSE WE'RE DEALING WITH A 2955 01:51:56,040 --> 01:51:58,960 MEMBRANE WHICH IS 5, 2956 01:51:58,960 --> 01:52:00,280 6-NANOMETERS THICK, AND SO THE 2957 01:52:00,280 --> 01:52:02,120 FIELD STRENGTH IS IN THE RANGE 2958 01:52:02,120 --> 01:52:05,440 OF 30 MILLION VOLTS PER METER. 2959 01:52:05,440 --> 01:52:06,840 WHICH IS EQUIVALENT TO A BOLT OF 2960 01:52:06,840 --> 01:52:07,080 LIGHTNING. 2961 01:52:07,080 --> 01:52:07,920 IT REALLY IS. 2962 01:52:07,920 --> 01:52:09,040 NOW THERE'S ANOTHER INTERESTING 2963 01:52:09,040 --> 01:52:09,840 THING, I'LL BE INTERESTED TO 2964 01:52:09,840 --> 01:52:12,520 KNOW WHAT YOU THINK ABOUT THIS, 2965 01:52:12,520 --> 01:52:16,560 JENNIFER, THERE'S A DIRTY SECRET 2966 01:52:16,560 --> 01:52:17,560 SECRET, WHICH IS THAT IT'S VERY, 2967 01:52:17,560 --> 01:52:18,880 VERY DIFFICULT TO MEASURE THE 2968 01:52:18,880 --> 01:52:19,600 MEMBRANE POTENTIAL. 2969 01:52:19,600 --> 01:52:22,680 IT'S USUALLY DONE WITH 2970 01:52:22,680 --> 01:52:26,800 FLUORESCENT DYES, SO THE 2971 01:52:26,800 --> 01:52:29,440 MITOCHONDRIAL MATRIX OR THE 2972 01:52:29,440 --> 01:52:33,160 INSIDE OF SOLID BACTERIA IS 2973 01:52:33,160 --> 01:52:34,880 RELATIVELY NEGATIVELY CHARGED, 2974 01:52:34,880 --> 01:52:36,000 SO THESE CAT IRONS WILL 2975 01:52:36,000 --> 01:52:37,080 ACCUMULATE IN THERE AND THEY 2976 01:52:37,080 --> 01:52:38,480 SHOULD CROSS THE MEMBRANE 2977 01:52:38,480 --> 01:52:40,120 BECAUSE THEARL -- IT ALL MAKES 2978 01:52:40,120 --> 01:52:41,320 SENSE BUT THEY INTERACT WITH 2979 01:52:41,320 --> 01:52:43,360 PROTEINS IN WAYS THAT ARE 2980 01:52:43,360 --> 01:52:46,600 DIFFICULT TO QUANTIFY, AND THE 2981 01:52:46,600 --> 01:52:48,320 STRUCTURE OF MITOCHONDRIA HAS 2982 01:52:48,320 --> 01:52:49,080 BECOME MUCH MORE INTERESTING 2983 01:52:49,080 --> 01:52:49,440 REALLY. 2984 01:52:49,440 --> 01:52:53,480 WE USED TO THINK, I USED TO 2985 01:52:53,480 --> 01:52:54,800 THINK OF THE CHRISTY STRUCTURES 2986 01:52:54,800 --> 01:52:55,960 BASICALLY OPEN AND CONTINUOUS 2987 01:52:55,960 --> 01:52:57,280 WITH THE INTERMEMBRANE SPACE, 2988 01:52:57,280 --> 01:52:59,280 BUT THEY'RE NOT. 2989 01:52:59,280 --> 01:53:00,800 THE ONE COMPLEX CLOSES THE 2990 01:53:00,800 --> 01:53:01,560 CHRISTY, THEY'RE VERY NARROW, 2991 01:53:01,560 --> 01:53:03,440 THEY'RE VERY CONFINED SPACES, 2992 01:53:03,440 --> 01:53:05,280 NOT MUCH WATER IN THERE, AND 2993 01:53:05,280 --> 01:53:06,840 THERE'S NOT CONTINUOUS WITH THE 2994 01:53:06,840 --> 01:53:07,360 INTERMEMBRANE SPACE. 2995 01:53:07,360 --> 01:53:11,720 SO THAT'S HOW THE LIPOPHILIC CAT 2996 01:53:11,720 --> 01:53:14,040 IONS CAN GET IN, THEY'RE NEVER 2997 01:53:14,040 --> 01:53:15,280 CROSSING SOMETHING WITH REALLY 2998 01:53:15,280 --> 01:53:16,240 STRONG POSITIVE CHARGE AS THEY 2999 01:53:16,240 --> 01:53:20,000 WOULD IF THEY CROSSED THE 3000 01:53:20,000 --> 01:53:20,240 CHRISTY. 3001 01:53:20,240 --> 01:53:22,200 BUT WHEN PEOPLE HAVE TRIED TO 3002 01:53:22,200 --> 01:53:26,120 TAKE MEASUREMENTS OF THE ACTUAL 3003 01:53:26,120 --> 01:53:27,280 MEMBRANE -- USING ELECTRODES, 3004 01:53:27,280 --> 01:53:30,160 THEY TEND TO MEASURE 10, 3005 01:53:30,160 --> 01:53:36,160 20 MILLIVOLTS VERY, VERY LOW. 3006 01:53:36,160 --> 01:53:38,120 NOW, THERE ARE STILL PEOPLE OUT 3007 01:53:38,120 --> 01:53:38,880 THERE INCLUDING SOME VERY GOOD 3008 01:53:38,880 --> 01:53:41,520 SIGN TIES THAT HAVE CHALLENGED 3009 01:53:41,520 --> 01:53:42,840 THE HYPOTHESIS ON THAT BASIS, 3010 01:53:42,840 --> 01:53:44,600 YOU MEASURE IT USING THE KIND OF 3011 01:53:44,600 --> 01:53:45,320 NEUROLOGICAL TOOLS THAT PEOPLE 3012 01:53:45,320 --> 01:53:47,080 USE FOR LOOKING AT NEURONS, AND 3013 01:53:47,080 --> 01:53:50,600 INSTEAD OF 200 MILL VOLTS, MILLIVOLTS, YO U 3014 01:53:50,600 --> 01:53:54,640 GET 10, 20 MILLIVOLTS. 3015 01:53:54,640 --> 01:53:57,080 WHAT WHAT THEY'RE MEASURING IS THE 3016 01:53:57,080 --> 01:53:58,800 DIFFERENCE BETWEEN THE CYTOSOL 3017 01:53:58,800 --> 01:54:00,000 AND THE MATRIX, NOND THE MATRIX 3018 01:54:00,000 --> 01:54:00,840 AND THE CHRISTY SPACE. 3019 01:54:00,840 --> 01:54:01,760 SO THEN THE QUESTION IS, AND 3020 01:54:01,760 --> 01:54:03,480 THIS IS MY QUESTION TO YOU, 3021 01:54:03,480 --> 01:54:04,360 JENNIFER, BECAUSE I DON'T KNOW 3022 01:54:04,360 --> 01:54:06,880 HOW YOU DO IT, HOW CAN WE 3023 01:54:06,880 --> 01:54:07,880 MEASURE -- IT'S HARD TO THINK OF 3024 01:54:07,880 --> 01:54:14,800 ANY OTHER WAY THAN USING DYES, 3025 01:54:14,800 --> 01:54:16,080 THAT'S GOING TO ACCUMULATE IN 3026 01:54:16,080 --> 01:54:16,960 THE CHRISTY SPACE AND TELL US 3027 01:54:16,960 --> 01:54:18,920 WHAT THE MEMBRANE POTENTIAL IS 3028 01:54:18,920 --> 01:54:20,480 BETWEEN THE CHRISTY AND THE 3029 01:54:20,480 --> 01:54:21,360 MATRIX. 3030 01:54:21,360 --> 01:54:22,680 NOW, THE OLD MEASUREMENTS THAT 3031 01:54:22,680 --> 01:54:25,640 PETER MITCHELL AND JENNIFER 3032 01:54:25,640 --> 01:54:27,080 MOYLE USED TO DO LOOKING AT 3033 01:54:27,080 --> 01:54:28,600 CHANGES IN PH, THEY ESTIMATED 3034 01:54:28,600 --> 01:54:29,680 THE MEMBRANE POTENTIAL TO BE IN 3035 01:54:29,680 --> 01:54:33,640 THE RANGE OF 230 MILLIVOLTS. 3036 01:54:33,640 --> 01:54:35,080 AND THAT CLIMBED DOWN AND 3037 01:54:35,080 --> 01:54:36,920 CLIMBED DOWN AND IT'S CALIBRATED 3038 01:54:36,920 --> 01:54:40,080 NOW USING THE CATIONS AND YOU 3039 01:54:40,080 --> 01:54:41,760 WON'T READ VERY OFTEN OF A 3040 01:54:41,760 --> 01:54:43,720 MEMBRANE POTENTIAL OF ABOUT 3041 01:54:43,720 --> 01:54:44,080 118 MILLIVOLTS. 3042 01:54:44,080 --> 01:54:47,480 BUT I DON'T KNOW WHAT IT'S BEING 3043 01:54:47,480 --> 01:54:47,880 CALIBRATED WITH. 3044 01:54:47,880 --> 01:54:49,520 PEOPLE TRY IN BACTERIA BY THE 3045 01:54:49,520 --> 01:54:51,720 ROTATION SPEED OF THE BACTERIAL 3046 01:54:51,720 --> 01:54:52,680 FLAGELLUM AND IT DOESN'T 3047 01:54:52,680 --> 01:54:54,040 CORRELATE VERY WELL AT ALL, SO I 3048 01:54:54,040 --> 01:54:56,280 DON'T THINK WE HAVE A VERY 3049 01:54:56,280 --> 01:54:57,280 RELIABLE WAY OF CALIBRATING WHAT 3050 01:54:57,280 --> 01:54:58,960 THE ACTUAL MEMBRANE POTENTIAL OF 3051 01:54:58,960 --> 01:55:03,200 THE CHRISTY IS, USING THE 3052 01:55:03,200 --> 01:55:04,720 LIPPHILIC CATIRONS BECAUSE WE 3053 01:55:04,720 --> 01:55:06,120 DON'T HAVE ANY WAY OF GETTING -- 3054 01:55:06,120 --> 01:55:07,800 MAYBE WE CAN DO IT BY EM 3055 01:55:07,800 --> 01:55:08,880 TOMOGRAPHY AND DOING THE 3056 01:55:08,880 --> 01:55:10,400 MEASUREMENTS WITH THE MATRIX 3057 01:55:10,400 --> 01:55:11,680 VALUES AND THEN CALCULATE THE 3058 01:55:11,680 --> 01:55:12,400 VOLUME AND CALCULATE IT THAT 3059 01:55:12,400 --> 01:55:12,680 WAY. 3060 01:55:12,680 --> 01:55:13,880 THAT MIGHT TELL US. 3061 01:55:13,880 --> 01:55:18,920 BUT THIS IS A QUESTION FOR YOU 3062 01:55:18,920 --> 01:55:21,080 AS A CELL BIOLOGIST WHO KNOWS 3063 01:55:21,080 --> 01:55:22,200 ALL ABOUT WAYS OF MEASURING 3064 01:55:22,200 --> 01:55:23,880 THESE THINGS, BECAUSE I'M AT A 3065 01:55:23,880 --> 01:55:25,720 BIT OF A LOSS, BUT I THINK WE'RE 3066 01:55:25,720 --> 01:55:27,080 ON THE POINT OF SOMETHING REALLY 3067 01:55:27,080 --> 01:55:29,640 FUNDAMENTAL HERE. 3068 01:55:29,640 --> 01:55:30,800 >> THAT'S REALLY COOL. 3069 01:55:30,800 --> 01:55:39,080 I MEAN, SO WE DO FOCUS ION BEAM 3070 01:55:39,080 --> 01:55:40,520 SCANNING MICROSCOPY AND RECENTLY 3071 01:55:40,520 --> 01:55:43,680 HAVE BEEN PRODUCING THESE DYES, 3072 01:55:43,680 --> 01:55:46,680 THESE MEMBRANE POTENTIAL DYES 3073 01:55:46,680 --> 01:55:48,280 INTO MITOCHONDRIA, AND YOU CAN 3074 01:55:48,280 --> 01:55:52,440 THEN DO CORRELATIVE IMAGING, YOU 3075 01:55:52,440 --> 01:55:55,800 CAN CORRELATE -- BASICALLY HIGH 3076 01:55:55,800 --> 01:55:56,920 PRESSURE FREEZING OF THE CELL 3077 01:55:56,920 --> 01:56:05,120 THAT'S JUST HAD THE DYE ADDED, 3078 01:56:05,120 --> 01:56:08,400 SO ITS CELLS FOE 16. 3079 01:56:08,400 --> 01:56:08,880 FROZEN. 3080 01:56:08,880 --> 01:56:10,480 TURNS OUT THE DYE IS FLUORESCENT 3081 01:56:10,480 --> 01:56:12,480 AND YOU CAN REALLY LOOK AT IT 3082 01:56:12,480 --> 01:56:13,880 RELATIVE TO THE REST OF THE 3083 01:56:13,880 --> 01:56:14,320 MITOCHONDRIA. 3084 01:56:14,320 --> 01:56:17,440 SO IT COULD BE THAT THAT SYSTEM 3085 01:56:17,440 --> 01:56:20,400 COULD BE USED. 3086 01:56:20,400 --> 01:56:21,360 WE HAVEN'T BEEN THINKING ABOUT 3087 01:56:21,360 --> 01:56:22,480 IT FROM THE PERSPECTIVE OF 3088 01:56:22,480 --> 01:56:24,880 TRYING TO GET A MORE ACCURATE 3089 01:56:24,880 --> 01:56:28,720 MEASUREMENT OF THE MEMBRANE 3090 01:56:28,720 --> 01:56:29,600 POTENTIAL, BUT MAYBE WE SHOULD 3091 01:56:29,600 --> 01:56:30,680 TALK TO YOU MORE ABOUT IT. 3092 01:56:30,680 --> 01:56:33,640 I'LL SEND YOU AN IMAGE OF WHAT 3093 01:56:33,640 --> 01:56:41,200 THIS LOOKS LIKE. 3094 01:56:41,200 --> 01:56:44,040 WHAT'S INTERESTING IS WE SEE 3095 01:56:44,040 --> 01:56:45,960 VARIABILITY OF THAT MEMBRANE 3096 01:56:45,960 --> 01:56:47,200 POTENTIAL DYE ACROSS THAT 3097 01:56:47,200 --> 01:56:47,520 MITOCHONDRIA. 3098 01:56:47,520 --> 01:56:49,400 >> BETWEEN CHRISTY AS WELL, I 3099 01:56:49,400 --> 01:56:49,680 UNDERSTAND. 3100 01:56:49,680 --> 01:56:50,240 >> YEAH. 3101 01:56:50,240 --> 01:56:52,200 MM-HMM. 3102 01:56:52,200 --> 01:56:52,600 YEAH. 3103 01:56:52,600 --> 01:56:53,640 >> JENNIFER, EXCUSE ME, BUT I 3104 01:56:53,640 --> 01:56:55,800 WAS REMINDED THAT YOU DIDN'T 3105 01:56:55,800 --> 01:56:58,680 HAVE AN OPPORTUNITY TO PROVIDE 3106 01:56:58,680 --> 01:57:02,120 YOUR DEFINITION OF LIFE. 3107 01:57:02,120 --> 01:57:09,040 >> WELL, I MEAN, I THINK I WILL 3108 01:57:09,040 --> 01:57:10,840 AGREE WITH NICK. 3109 01:57:10,840 --> 01:57:16,280 I'VE BEEN IN MANY CONVERSATIONS, 3110 01:57:16,280 --> 01:57:16,880 DEBATES, ARGUMENTS ABOUT THE 3111 01:57:16,880 --> 01:57:20,680 DEFINITION OF LIFE, AND I THINK 3112 01:57:20,680 --> 01:57:23,520 IT'S -- BASICALLY IT'S A 3113 01:57:23,520 --> 01:57:26,280 PROCESS, IT'S AN ENERGY FLUX. 3114 01:57:26,280 --> 01:57:28,440 THAT'S THE TYPICAL DEFINITIONS, 3115 01:57:28,440 --> 01:57:32,400 WHEN PEOPLE TALK ABOUT 3116 01:57:32,400 --> 01:57:35,880 SELF-REPLICATING CONTAINING DNA, 3117 01:57:35,880 --> 01:57:36,160 A MEMBRANE. 3118 01:57:36,160 --> 01:57:37,280 >> IT'S KIND OF MORE OF A 3119 01:57:37,280 --> 01:57:38,280 DESCRIPTION THAN A DEFINITION, 3120 01:57:38,280 --> 01:57:38,800 THOUGH, ISN'T IT? 3121 01:57:38,800 --> 01:57:42,560 >> EXACTLY. 3122 01:57:42,560 --> 01:57:43,880 I THINK WHAT LIFE IS IS 3123 01:57:43,880 --> 01:57:46,160 BASICALLY BEING ABLE TO TAKE -- 3124 01:57:46,160 --> 01:57:50,920 HARVEST ENERGY TO DRIVE 3125 01:57:50,920 --> 01:57:51,200 PROCESSES. 3126 01:57:51,200 --> 01:57:53,360 IN A WAY THAT'S WAY OUT OF 3127 01:57:53,360 --> 01:57:55,880 EQUILIBRIUM. 3128 01:57:55,880 --> 01:57:57,440 BUT I REALIZE THAT THAT ALLOWS 3129 01:57:57,440 --> 01:58:01,560 YOU TO EXTEND THE DEFINITION TO 3130 01:58:01,560 --> 01:58:03,440 SOMETHING BIGGER POTENTIALLY 3131 01:58:03,440 --> 01:58:06,800 THAN CELLS. 3132 01:58:06,800 --> 01:58:08,680 AND IS THE WHOLE EARTH A LIVING 3133 01:58:08,680 --> 01:58:09,880 THING. 3134 01:58:09,880 --> 01:58:12,040 YOU KNOW. 3135 01:58:12,040 --> 01:58:14,800 THIS WHOLE IDEA THAT EARTH IS -- 3136 01:58:14,800 --> 01:58:15,520 IT'S A SYSTEM. 3137 01:58:15,520 --> 01:58:18,520 IT A LIVING SYSTEM, IT'S NOT -- 3138 01:58:18,520 --> 01:58:20,040 >> IT HAS A STRUCTURE VERY 3139 01:58:20,040 --> 01:58:24,400 SIMILAR TO A CELL IN THE SENSORY 3140 01:58:24,400 --> 01:58:27,280 DUED, RELATIVELY ALKALINE -- 3141 01:58:27,280 --> 01:58:31,640 ASIC DICK 3142 01:58:31,640 --> 01:58:33,840 ACYTIC AND OXIDIZED ON THE 3143 01:58:33,840 --> 01:58:34,080 OUTSIDE. 3144 01:58:34,080 --> 01:58:35,320 CELLS MIMIC THE STRUCTURE OF THE 3145 01:58:35,320 --> 01:58:35,520 EARTH. 3146 01:58:35,520 --> 01:58:37,480 THERE IS A DEFINITION OF LIFE, A 3147 01:58:37,480 --> 01:58:41,040 WORKING DEFINITION OF LIFE THAT 3148 01:58:41,040 --> 01:58:41,600 MASSA HAVE. 3149 01:58:41,600 --> 01:58:43,000 I PROBABLY CAN'T GET THIS QUITE 3150 01:58:43,000 --> 01:58:45,720 RIGHT, BUT IT'S SOMETHING LIKE A 3151 01:58:45,720 --> 01:58:51,000 SELF SUSTAINED DAR DARWINIAN 3152 01:58:51,000 --> 01:58:52,280 EVOLUTION, SOMETHING ALONG THOSE 3153 01:58:52,280 --> 01:58:52,960 LINES. 3154 01:58:52,960 --> 01:58:54,080 I REBEL AGAINST SELF SUSTAINED 3155 01:58:54,080 --> 01:58:55,040 BECAUSE IT DENIGRATES THE 3156 01:58:55,040 --> 01:58:56,880 ENVIRONMENT TO THE POINT OF 3157 01:58:56,880 --> 01:58:57,240 NON-EXISTENCE. 3158 01:58:57,240 --> 01:58:58,960 I KNOW WHAT THEY MEAN, BUT IT 3159 01:58:58,960 --> 01:59:04,320 CERTAINLY DOESN'T EMPHASIZE AN 3160 01:59:04,320 --> 01:59:05,960 ENVIRONMENTAL DISEQUILIBRIUM 3161 01:59:05,960 --> 01:59:07,280 DRIVING EVERYTHING. 3162 01:59:07,280 --> 01:59:08,480 PEOPLE CAN POKE FUN, BY THAT 3163 01:59:08,480 --> 01:59:11,000 DEFINITION ONLY A PAIR OF 3164 01:59:11,000 --> 01:59:16,880 RABBITS IS ALIVE, A SINGLE 3165 01:59:16,880 --> 01:59:17,800 RABBIT -- COPY ITSELF. 3166 01:59:17,800 --> 01:59:19,880 SO ALL OF THESE DEFINITIONS HAVE 3167 01:59:19,880 --> 01:59:21,560 HOLES IN THEM, ALMOST RISIBLE 3168 01:59:21,560 --> 01:59:24,280 HOLE, AND YOU'RE LEFT WITH THIS 3169 01:59:24,280 --> 01:59:25,320 FEELING, ARE WE ACTUALLY 3170 01:59:25,320 --> 01:59:26,600 LEARNING ANYTHING FROM MAKING 3171 01:59:26,600 --> 01:59:27,680 FUN AT OTHER PEOPLE'S 3172 01:59:27,680 --> 01:59:28,000 DEFINITIONS? 3173 01:59:28,000 --> 01:59:29,240 I THINK THERE'S A PROBLEM WITH 3174 01:59:29,240 --> 01:59:30,080 DEFINITIONS ALL TOGETHER WHEN IT 3175 01:59:30,080 --> 01:59:31,200 COMES TO LIFE JUST BECAUSE IT'S 3176 01:59:31,200 --> 01:59:34,120 A CONTINUUM. 3177 01:59:34,120 --> 01:59:35,480 >> WELL, ON THAT SOBER NOTE, I 3178 01:59:35,480 --> 01:59:37,240 HAVE TO NOTE THAT WE HAVE 3179 01:59:37,240 --> 01:59:40,280 REACHED THE LIMIT OF OUR TIME. 3180 01:59:40,280 --> 01:59:40,960 >> OH, MY GOSH. 3181 01:59:40,960 --> 01:59:41,480 THAT WAS FAST. 3182 01:59:41,480 --> 01:59:46,400 >> HOWEVER, ON BEHALF OF THE 3183 01:59:46,400 --> 01:59:47,320 MANY, MANY, MANY PEOPLE WHO 3184 01:59:47,320 --> 01:59:49,160 WATCHED AND PARTICIPATE IN THIS, 3185 01:59:49,160 --> 01:59:51,240 I JUST WANT TO BE THE SPOKESMAN 3186 01:59:51,240 --> 01:59:55,960 TO THANK YOU BOTH FOR INFORMING, 3187 01:59:55,960 --> 01:59:57,160 EXCITING AND CERTAINLY 3188 01:59:57,160 --> 02:00:02,000 STIMULATING THE HELL OUT OF OUR 3189 02:00:02,000 --> 02:00:03,760 THINKING, AND IT MAKES ME REAL 3190 02:00:03,760 --> 02:00:04,720 REALIZE THAT THERE ARE PROBABLY 3191 02:00:04,720 --> 02:00:06,160 AT LEAST FIVE OTHER SUBJECTS 3192 02:00:06,160 --> 02:00:09,280 RELATED TO THE COMBINED 3193 02:00:09,280 --> 02:00:10,120 INTERESTS OF YOU TWO THAT MAYBE 3194 02:00:10,120 --> 02:00:13,680 WE CAN APPROACH ON ANOTHER 3195 02:00:13,680 --> 02:00:16,080 OCCASION. 3196 02:00:16,080 --> 02:00:17,080 SO THANK YOU VERY, VERY MUCH FOR 3197 02:00:17,080 --> 02:00:19,240 TAKING PART OF THIS, AND WE 3198 02:00:19,240 --> 02:00:20,960 GRATEFULLY APPRECIATE IT. 3199 02:00:20,960 --> 02:00:22,280 I'M SOOR OH, BUT ALL GOOD THINGS 3200 02:00:22,280 --> 02:00:25,280 HAVE TO SORRY, BUT ALL GOOD THINGS 3201 02:00:25,280 --> 02:00:26,960 MUST COME TO AN END. 3202 02:00:26,960 --> 00:00:00,000 >> THANK YOU VERY MUCH.