1 00:00:05,880 --> 00:00:10,000 >> WELCOME, EVERYONE. TO THE 2 00:00:10,000 --> 00:00:15,600 12TH SESSION IN THE 22ND YEAR OF 3 00:00:15,600 --> 00:00:18,040 A COURSE AT THE NATIONAL 4 00:00:18,040 --> 00:00:21,200 INSTITUTES OF HEALT HEALTH IN 5 00:00:21,200 --> 00:00:22,520 BETHESDA, MARYLAND. THE COURSE 6 00:00:22,520 --> 00:00:28,440 IS CALLED DEMYSTIFYING MEDICINE 7 00:00:28,440 --> 00:00:30,960 I'M WIN ARIAS. I'M A SENIOR 8 00:00:30,960 --> 00:00:32,840 SCIENTIST EMERITUS AND WITH MY 9 00:00:32,840 --> 00:00:40,480 COLLEAGUE DAN KASTNER WHO IS A 10 00:00:40,480 --> 00:00:42,320 SENIOR INVESTIGATOR AND FORMER 11 00:00:42,320 --> 00:00:44,720 DIRECTOR, PART OF THE HUMAN 12 00:00:44,720 --> 00:00:46,280 GENOME RESEARCH INSTITUTE WE 13 00:00:46,280 --> 00:00:49,160 WELCOME YOU TO THIS SESSION. LET 14 00:00:49,160 --> 00:00:51,200 ME EXPLAIN. THE GENERAL PURPOSE 15 00:00:51,200 --> 00:00:53,600 OF THE COURSE IS TO BRIDGE THE 16 00:00:53,600 --> 00:00:56,040 EXCITING DEVELOPMENTS IN BIOLOGY 17 00:00:56,040 --> 00:00:58,560 AND ENGINEERING WITH MEDICINE. 18 00:00:58,560 --> 00:01:01,800 FOR THE MOST PART WE DO IT WITH 19 00:01:01,800 --> 00:01:03,280 HUMAN -- DEAL WITH HUMAN 20 00:01:03,280 --> 00:01:06,200 DISEASE, WHICH ARE PRESENTED 21 00:01:06,200 --> 00:01:08,840 SOMETIMES THROUGH LIVE PATIENTS, 22 00:01:08,840 --> 00:01:12,560 BUT ALWAYS WITH REPRESENTATIVES 23 00:01:12,560 --> 00:01:16,880 OF A CLINICAL ARENA AND ALSO A 24 00:01:16,880 --> 00:01:19,240 STATE OF THE ART BASIC 25 00:01:19,240 --> 00:01:21,520 SCIENTIST. IT IS MUCH LIKE THE 26 00:01:21,520 --> 00:01:23,360 LOGO IN THE UPPER RIGHT PART OF 27 00:01:23,360 --> 00:01:27,440 THE SLIDE WHICH IS, MANY OF US 28 00:01:27,440 --> 00:01:28,880 THE MOST FAMOUS BRIDGE IN THE 29 00:01:28,880 --> 00:01:30,480 WORLD, THAT IS EASTERN 30 00:01:30,480 --> 00:01:31,560 PAROCHIALISM, IN NEW YORK THAT'S 31 00:01:31,560 --> 00:01:33,320 THE BROOKLYN BRIDGE CONNECTING 32 00:01:33,320 --> 00:01:35,360 BROOKLYN AND MANHATTAN. AND 33 00:01:35,360 --> 00:01:38,920 TODAY ONCE AGAIN, LIKE THE TWO 34 00:01:38,920 --> 00:01:40,480 GENTLEMEN ON THE CAT WALK, WE 35 00:01:40,480 --> 00:01:43,720 ARE DISCUSSING A MAJOR PROBLEM. 36 00:01:43,720 --> 00:01:46,680 IN FACT, ONE MIGHT SAY IT IS THE 37 00:01:46,680 --> 00:01:50,600 MAJOR PROBLEM IN ALL OF BIOLOGY. 38 00:01:50,600 --> 00:01:53,720 WE ARE DISCUSSING THE QUESTIONS 39 00:01:53,720 --> 00:01:57,480 LIKE THE ORIGIN OF LIFE. THE 40 00:01:57,480 --> 00:02:00,160 DEVELOPMENT OF THE EUKARYOTIC 41 00:02:00,160 --> 00:02:01,800 CELL AND MAYBE THESE TWO FOLKS 42 00:02:01,800 --> 00:02:04,480 ARE ASKING THEMSELVES ARE THE 43 00:02:04,480 --> 00:02:07,160 HUMAN SPECIES REALLY AS 44 00:02:07,160 --> 00:02:08,800 IMPORTANT ON THIS EARTH AND ITS 45 00:02:08,800 --> 00:02:10,160 CREATION AND DEVELOPMENT AS WE 46 00:02:10,160 --> 00:02:13,960 THINK THEY ARE. ALL OF THESE 47 00:02:13,960 --> 00:02:15,040 SEEMINGLY DIVERSE TOPICS ARE 48 00:02:15,040 --> 00:02:17,200 GOING TO BE ADDRESSED TODAY. 49 00:02:17,200 --> 00:02:21,280 OVERALL PURPOSE OF THIS COURSE 50 00:02:21,280 --> 00:02:22,640 SYMBOLICALLY IS TO BRIDGE WHAT 51 00:02:22,640 --> 00:02:27,360 ARE SILOS OF INFORMATION. 52 00:02:27,360 --> 00:02:29,240 EXPERTISE IN DIFFERENT AREAS OF 53 00:02:29,240 --> 00:02:30,720 MEDICINE AND BIOLOGY AND 54 00:02:30,720 --> 00:02:36,080 ENGINEERING NORMALLY MAY NOT 55 00:02:36,080 --> 00:02:39,000 COMMUNICATE MUCH WITH ONE 56 00:02:39,000 --> 00:02:42,360 ANOTHER. THE GOAL IS TO CONVERT 57 00:02:42,360 --> 00:02:45,040 THIS ESSENTIALLY INTO BRIDGES. 58 00:02:45,040 --> 00:02:50,560 TODAY WE ARE ADDRESSING ONE OF 59 00:02:50,560 --> 00:02:51,800 THE BROADER OPPORTUNITY IN 60 00:02:51,800 --> 00:02:54,600 BIOLOGY AND I WILL GET TO THAT 61 00:02:54,600 --> 00:02:55,920 IN A MOMENT. WE HAVE NEXT SLIDE 62 00:02:55,920 --> 00:03:06,440 PLEASE. NEXT. THE CME CREDIT 63 00:03:08,560 --> 00:03:12,240 45386. THERE IS THE PHONE 64 00:03:12,240 --> 00:03:21,320 NUMBER, (443)541-5052. CAN 65 00:03:21,320 --> 00:03:23,880 SPEAKER HAS NO FINANCIAL 66 00:03:23,880 --> 00:03:30,120 RELATIONSHIP. WHEN ONE AT LEAST 67 00:03:30,120 --> 00:03:31,800 WHEN I WAS A COLLEGE STUDENT 68 00:03:31,800 --> 00:03:35,120 WHEN ONE THOUGHT OF GEOLOGY IT 69 00:03:35,120 --> 00:03:38,000 WAS ROCKS. THE INTEREST WAS SORT 70 00:03:38,000 --> 00:03:41,000 OF IN CLASSIFICATION 71 00:03:41,000 --> 00:03:43,000 UNDERSTANDING SOMETHING OF THEIR 72 00:03:43,000 --> 00:03:45,920 FORMATION, BUT IT BASICALLY WAS 73 00:03:45,920 --> 00:03:49,680 PRETTY HARD SCIENCE IF YOU WILL 74 00:03:49,680 --> 00:03:51,640 ONE OF MY PROFESSOR, MANY YEARS 75 00:03:51,640 --> 00:03:58,640 AGO WAS WAY AHEAD OF THE CURVE. 76 00:03:58,640 --> 00:04:05,280 THIS IS KIRTLEY MATHER PROFESSOR 77 00:04:05,280 --> 00:04:06,800 UNIVERSITY OF HARVARD, THE LAWS 78 00:04:06,800 --> 00:04:10,680 OF NATURE ARE NOT CHAINS WHICH 79 00:04:10,680 --> 00:04:12,360 SHACKLE MANOR GODS WHICH DRIVE 80 00:04:12,360 --> 00:04:13,440 HIM DOWN ANY PREDETERMINED 81 00:04:13,440 --> 00:04:15,000 ALLEY. THEY ARE TOOLS WHICH 82 00:04:15,000 --> 00:04:17,560 STRENGTHSEN HIS HANDS AND 83 00:04:17,560 --> 00:04:19,200 INCREASE HIS EFFICIENCY. THEIR 84 00:04:19,200 --> 00:04:20,400 IMPLEMENTS WHICH HAVE WAITED 85 00:04:20,400 --> 00:04:25,240 LONG FOR HIS MASTER MIND TO MAKE 86 00:04:25,240 --> 00:04:29,240 THEM USEFUL. IN THE MANY YEARS 87 00:04:29,240 --> 00:04:32,320 SINCE KIRTLEY AND OTHERS 88 00:04:32,320 --> 00:04:33,880 ADDRESSED ISSUES LIKE THIS, 89 00:04:33,880 --> 00:04:39,680 THERE WAS A SEPARATION BETWEEN 90 00:04:39,680 --> 00:04:42,440 GEOLOGY AND BIOLOGY. NEXT SLIDE 91 00:04:42,440 --> 00:04:44,080 PLEASE. MANY LEADING BIOLOGISTS 92 00:04:44,080 --> 00:04:48,280 FOR EXAMPLE, SIDNEY BRENNER, 93 00:04:48,280 --> 00:04:49,640 SOMEWHAT FACETIOUSLY WROTE ONE 94 00:04:49,640 --> 00:04:51,160 OF THE THINGS ABOUT CREATIVITY 95 00:04:51,160 --> 00:04:53,960 IS NOT TO BE AFRAID OF SAYING 96 00:04:53,960 --> 00:04:57,720 THE WRONG THING, WHICH IS TRUE. 97 00:04:57,720 --> 00:05:00,760 SO WE ARE VERY PRIVILEGED TODAY 98 00:05:00,760 --> 00:05:06,280 TO HAVE AS OUR SPEAKER ANDREW 99 00:05:06,280 --> 00:05:10,760 KNOLL, WHO RECEIVED DEGREES IN 100 00:05:10,760 --> 00:05:14,280 GEOLOGY AT LEE HIGH UNIVERSITY 101 00:05:14,280 --> 00:05:15,840 AND Ph.D. AT HARVARD. 102 00:05:15,840 --> 00:05:18,440 FOLLOWED WHICH HE SPENT FIVE 103 00:05:18,440 --> 00:05:20,040 YEARS IN OVERLAND TEACHING ON 104 00:05:20,040 --> 00:05:22,800 THE FACULTY AND IN 1982 HE 105 00:05:22,800 --> 00:05:25,640 RETURNED TO HARVARD WHERE HE HAS 106 00:05:25,640 --> 00:05:30,080 REMAINED. IS EMERITUS PROFESSOR 107 00:05:30,080 --> 00:05:32,480 OF BIOLOGY AT EARTH AND 108 00:05:32,480 --> 00:05:34,480 PLANETARY SCIENCES. AND 109 00:05:34,480 --> 00:05:37,720 CURRENTLY A FISHER PROFESSOR OF 110 00:05:37,720 --> 00:05:44,520 NATURAL HISTORY. HIS MAIN 111 00:05:44,520 --> 00:05:47,280 ACTIVITIES HAVE BEEN TO DRAW 112 00:05:47,280 --> 00:05:49,920 CONNECTIONS BETWEEN THE ORIGIN 113 00:05:49,920 --> 00:05:51,800 OF LIFE AND THE ENVIRONMENTAL 114 00:05:51,800 --> 00:05:56,480 HISTORY OF THE EARTH. THIS 115 00:05:56,480 --> 00:05:59,040 IMPORTANT FIELD UNDERLIES AND 116 00:05:59,040 --> 00:06:01,000 CREATES VERY DIFFERENT OPINIONS 117 00:06:01,000 --> 00:06:04,400 AS TO THE ORIGIN OF LIFE BUT 118 00:06:04,400 --> 00:06:07,840 HERE THE EMPHASIS IS ON THE 119 00:06:07,840 --> 00:06:08,840 INTERACTION BETWEEN THE 120 00:06:08,840 --> 00:06:12,240 ENVIRONMENT OF THE EARTH AS IT 121 00:06:12,240 --> 00:06:13,360 CHANGES AND PARTICULARLY THE 122 00:06:13,360 --> 00:06:18,000 ROLE OF BACTERIA, AND THEIR 123 00:06:18,000 --> 00:06:20,520 RELATIONSHIP TO LIFE, TO 124 00:06:20,520 --> 00:06:22,760 EVOLUTION AND TO SOME EXTENT AS 125 00:06:22,760 --> 00:06:25,360 WE WILL SEE AND DISCUSS TO HUMAN 126 00:06:25,360 --> 00:06:31,200 DISEASE. PROFESSOR KNOLL HAS 127 00:06:31,200 --> 00:06:32,360 MANY HONORS A MEMBER OF THE 128 00:06:32,360 --> 00:06:34,200 NATIONAL ACADEMY OF SCIENCE, THE 129 00:06:34,200 --> 00:06:36,640 ACADEMY OF ARTS AND SCIENCES, 130 00:06:36,640 --> 00:06:38,640 THE PHILOSOPHICAL SOCIETY, AND 131 00:06:38,640 --> 00:06:44,200 THE ACADEMY OF MICROBIOLOGY. HE 132 00:06:44,200 --> 00:06:47,280 RECEIVED THE THOMPSON AWARDS OF 133 00:06:47,280 --> 00:06:48,880 NATIONAL ACADEMY OF SCIENCES AND 134 00:06:48,880 --> 00:06:50,560 ONE OF HIS BOOKS, A WONDERFUL 135 00:06:50,560 --> 00:06:52,800 BOOK CALLED LIFE ON A YOUNG 136 00:06:52,800 --> 00:06:55,920 PLANET RECEIVED THE PHI BETA 137 00:06:55,920 --> 00:06:58,120 KAPPA BOOK AWARD, HE'S RECEIVED 138 00:06:58,120 --> 00:07:01,400 REWARDS FROM THE SOCIETY FOR 139 00:07:01,400 --> 00:07:03,680 SEDIMENTARY GEOLOGY PALEONTOLOGY 140 00:07:03,680 --> 00:07:09,200 AND GEOLOGY. AND IN 2022 HE 141 00:07:09,200 --> 00:07:11,200 RECEIVED THE PRESTIGIOUS 142 00:07:11,200 --> 00:07:14,080 CRAWFORD PRIZE IN GEOSCIENCES 143 00:07:14,080 --> 00:07:15,640 GIVEN BY THE ROYAL SWEDISH 144 00:07:15,640 --> 00:07:21,120 ACADEMY. PROFESSOR KNOLL HAS 145 00:07:21,120 --> 00:07:25,440 ALSO SERVED ON THE SCIENCE TEAM 146 00:07:25,440 --> 00:07:29,080 FOR THE NASA MISSION TO MARS AND 147 00:07:29,080 --> 00:07:38,200 I TRUST THAT WILL IN OUR 148 00:07:38,200 --> 00:07:40,800 DISCUSSION. TH THE TITLE OF HIS 149 00:07:40,800 --> 00:07:42,480 TALK TODAY IS IT IS A BACTERIAL 150 00:07:42,480 --> 00:07:45,240 WORLD. ANDY, THANK YOU, VERY 151 00:07:45,240 --> 00:07:46,840 MUCH ON BEHALF OF ALL OF US FOR 152 00:07:46,840 --> 00:07:48,760 YOUR TAKING THE TIME TO JOIN US 153 00:07:48,760 --> 00:07:50,080 AND WE LOOK FORWARD TO YOUR 154 00:07:50,080 --> 00:07:52,680 TALK. WELCOME. 155 00:07:52,680 --> 00:07:54,000 >> THANK YOU, WIN. 156 00:07:54,000 --> 00:07:59,760 FIRST LET ME 157 00:07:59,760 --> 00:08:01,440 THANK WIN AND DAN KASTNER FOR 158 00:08:01,440 --> 00:08:02,320 INVITING ME TO BE WITH YOU 159 00:08:02,320 --> 00:08:07,840 TODAY. TO MANUFACTURE IT IS 160 00:08:07,840 --> 00:08:10,120 SURPRISING TO BE SPEAKING AT 161 00:08:10,120 --> 00:08:12,240 DEMYSTIFYING MEDICINE BECAUSE 162 00:08:12,240 --> 00:08:14,240 I AM NEITHER A PHYSICIAN NOR 163 00:08:14,240 --> 00:08:20,320 MEDICAL RESEARCHER, I DON'T HAVE 164 00:08:20,320 --> 00:08:22,480 MUCH POSSIBILITY OF DEMYSTIFYING 165 00:08:22,480 --> 00:08:23,840 MEDICINE FOR YOU. WHAT I DO DO 166 00:08:23,840 --> 00:08:25,520 IS PRACTICE SOMETHING CALLED 167 00:08:25,520 --> 00:08:29,480 GEOBIOLOGY WHICH IS AN EFFORT TO 168 00:08:29,480 --> 00:08:32,080 UNDERSTAND HOW PHYSICAL AND 169 00:08:32,080 --> 00:08:33,360 BIOLOGICAL PROCESSES IN CONCERTS 170 00:08:33,360 --> 00:08:34,160 SHAPED THE WORLD AROUND US 171 00:08:34,160 --> 00:08:41,080 TODAY. IF NOTHING ELSE THAT 172 00:08:41,080 --> 00:08:43,560 WILL HELP TO DEMYSTIFY BACTERIA. 173 00:08:43,560 --> 00:08:45,960 THERE IS A COMMON VIEW THESE 174 00:08:45,960 --> 00:08:49,080 BACTERIA OR PESKY ORGANISMS 175 00:08:49,080 --> 00:08:50,320 INTERPOLATED INTO A WORLD 176 00:08:50,320 --> 00:08:51,760 LARGELY DEFINED BY PLANTS AND 177 00:08:51,760 --> 00:08:55,280 ANIMAL BUS THE MAIN THING I WANT 178 00:08:55,280 --> 00:09:00,200 TO GET ACROSS TODAY IS THAT 179 00:09:00,200 --> 00:09:02,320 PRECISELY THE OPPOSITE IS TRUE. 180 00:09:02,320 --> 00:09:05,520 I HAVE ASKED OUR FINANCIAL 181 00:09:05,520 --> 00:09:07,400 DISCLOSURE SLIDE, I HAVE NOTHING 182 00:09:07,400 --> 00:09:08,960 TO DISCLOSE, I DON'T DO RESEARCH 183 00:09:08,960 --> 00:09:10,400 IN ANY AREA OF BIOMEDICAL 184 00:09:10,400 --> 00:09:14,360 INTEREST. ALSO I THINK IT IS A 185 00:09:14,360 --> 00:09:15,600 NICE THING THAT I WAS ASKED TO 186 00:09:15,600 --> 00:09:18,120 PROVIDE LEARNING OBJECTIVES. AND 187 00:09:18,120 --> 00:09:22,480 THE MAIN ONE IS TO SHARE MY 188 00:09:22,480 --> 00:09:25,080 SENSE HOW MICROORGANISMS PROVIDE 189 00:09:25,080 --> 00:09:27,280 THE FUNDAMENTAL ECOLOGICAL 190 00:09:27,280 --> 00:09:28,520 CIRCUITRY OF EARTH AND THEY HAVE 191 00:09:28,520 --> 00:09:32,080 DONE SO FOR MOST OF OUR PLANET'S 192 00:09:32,080 --> 00:09:35,080 HISTORY. IS IN CONTRAST TO THAT, 193 00:09:35,080 --> 00:09:37,640 COMPLEX MULTI-CELLULAR LIFE HAS 194 00:09:37,640 --> 00:09:40,160 ONLY BEEN AROUND THE LAST 20% OF 195 00:09:40,160 --> 00:09:43,720 THAT HISTORY AND HAS REALLY BEEN 196 00:09:43,720 --> 00:09:45,400 INTERPOLATED INTO FUNCTIONING 197 00:09:45,400 --> 00:09:48,080 ECOSYSTEMS BUILT ON MICROBIAL 198 00:09:48,080 --> 00:09:50,520 METABOLISMS. SO PERHAPS THAT 199 00:09:50,520 --> 00:09:52,520 MIGHT RESONATE WITH SOME OF YOU 200 00:09:52,520 --> 00:09:56,280 AS YOU THINK ABOUT THE 201 00:09:56,280 --> 00:09:59,480 RELATIONSHIPS BETWEEN MICROBES 202 00:09:59,480 --> 00:10:02,080 AND HUMANS. WE'LL START OUT WITH 203 00:10:02,080 --> 00:10:03,320 SOMETHING Y'ALL LEARNED IN HIGH 204 00:10:03,320 --> 00:10:06,720 SCHOOL AND THAT IS THAT CARBON 205 00:10:06,720 --> 00:10:08,040 CYCLES THROUGH THE BIOSPHERE AND 206 00:10:08,040 --> 00:10:09,760 HERE IS JUST A VERY SIMPLE 207 00:10:09,760 --> 00:10:12,320 CARBON CYCLE, IN WHICH WE HAVE 208 00:10:12,320 --> 00:10:13,880 PHOTO SYNTHESIS ON ONE SIDE OF 209 00:10:13,880 --> 00:10:15,200 THE CYCLE AND RESPIRATION ON THE 210 00:10:15,200 --> 00:10:19,080 OTHER. SO PLANTS TAKE CO 2 AND 211 00:10:19,080 --> 00:10:22,640 USE ELECTRONS DERIVED FROM WATER 212 00:10:22,640 --> 00:10:25,320 TO REDUCE THE CO 2 TO 213 00:10:25,320 --> 00:10:27,520 CARBOHYDRATES AND GIVE OFF 214 00:10:27,520 --> 00:10:29,040 OXYGEN GAS AS A PRODUCT. ALL OF 215 00:10:29,040 --> 00:10:30,880 US AS WE SIT HERE ARE DOING 216 00:10:30,880 --> 00:10:33,880 REVERSE REACTION WHERE WE TAKE 217 00:10:33,880 --> 00:10:36,320 CARBOHYDRATES AND OXYGEN AND 218 00:10:36,320 --> 00:10:39,520 DERIVE ENERGY FROM THE OXIDATION 219 00:10:39,520 --> 00:10:43,000 OF THE ORGANICS TO CO 2 AND THAT 220 00:10:43,000 --> 00:10:45,080 GIVES OFF WATER AND BECAUSE 221 00:10:45,080 --> 00:10:47,160 THESE TWO SITE OF THESE TWO 222 00:10:47,160 --> 00:10:48,760 PROCESSES ARE COMPLIMENTARY THAT 223 00:10:48,760 --> 00:10:52,400 RESULTS IN SOMETHING OF A CYCLE 224 00:10:52,400 --> 00:10:55,640 THAT IS ALL WELL AND GOOD. BUT 225 00:10:55,640 --> 00:10:58,160 NOTICE THE ROLE OF OXYGEN IN 226 00:10:58,160 --> 00:10:59,720 THIS CYCLE WE GENERALLY THINK OF 227 00:10:59,720 --> 00:11:03,280 THE CARBON CYCLE IN TERMS OF 228 00:11:03,280 --> 00:11:06,640 CARBON BUT IT IS FUNDAMENTALLY 229 00:11:06,640 --> 00:11:08,360 CYCLING OF WATER AND OXYGEN GAS 230 00:11:08,360 --> 00:11:11,120 AS WELL AND THAT RAISES THE 231 00:11:11,120 --> 00:11:13,560 QUESTION OF CAN WE CYCLE CARBON 232 00:11:13,560 --> 00:11:15,760 IN THE ABSENCE OF OXYGEN? THAT 233 00:11:15,760 --> 00:11:24,000 IS NOT JUST A SORT OF GENERAL 234 00:11:24,000 --> 00:11:26,200 QUESTION BECAUSE THERE ARE 235 00:11:26,200 --> 00:11:28,360 MANIMENT eMENTMENTS ARE OX 236 00:11:28,360 --> 00:11:29,840 GENERAL IS ABSENT, THERE'S 237 00:11:29,840 --> 00:11:31,720 OXYGEN MINERAL ZONES IN THE 238 00:11:31,720 --> 00:11:34,640 OCEAN, PRETTY MUCH ALL STEAD 239 00:11:34,640 --> 00:11:37,720 MEANTS, BELOW THE FEW 240 00:11:37,720 --> 00:11:39,160 CENTIMETERS ARE AN OXIC, THERE'S 241 00:11:39,160 --> 00:11:40,720 SWAMPS THE INSIDE OF YOUR BODIES 242 00:11:40,720 --> 00:11:41,840 SO THERE'S MANY ENVIRONMENT 243 00:11:41,840 --> 00:11:43,320 WHERE IS OXYGEN DOESN'T PLAY A 244 00:11:43,320 --> 00:11:45,720 ROLE AND WE CAN ASK ABOUT CARBON 245 00:11:45,720 --> 00:11:50,440 CYCLING IN THOSE ENVIRONMENTS. 246 00:11:50,440 --> 00:11:53,560 IT TURNS OUT THERE ARE QUITE A 247 00:11:53,560 --> 00:11:55,560 VARIETY OF METABOLISMS THAT ARE 248 00:11:55,560 --> 00:11:58,400 NOT KNOWN IN PLANTS AND PANELS 249 00:11:58,400 --> 00:11:59,240 THAT ACCOMPLISH THIS. SO WHEN 250 00:11:59,240 --> 00:12:02,280 YOU SEE ON THE RIGHT THERE IS 251 00:12:02,280 --> 00:12:06,920 SIMPLY A PHYLOGENY OF BACTERIA 252 00:12:06,920 --> 00:12:08,440 AND THE GREEN CLADES THAT ARE 253 00:12:08,440 --> 00:12:10,720 MARKED THERE ARE ALL PHOTO 254 00:12:10,720 --> 00:12:11,880 SYNTHETIC SO THERE ARE SEVEN 255 00:12:11,880 --> 00:12:15,280 WELL CHARACTERIZED SYNTHETIC 256 00:12:15,280 --> 00:12:16,800 PLATES WITHIN BACTERIA AND JUST 257 00:12:16,800 --> 00:12:21,320 A FEW MONTHS AGO AN 8TH ONE WAS 258 00:12:21,320 --> 00:12:23,040 DESCRIBED, THOUGH NOT FULLY YET 259 00:12:23,040 --> 00:12:24,200 CHARACTERIZED. WHAT IS 260 00:12:24,200 --> 00:12:25,440 INTERESTING ABOUT THAT IS THAT 261 00:12:25,440 --> 00:12:27,920 ONLY ONE OF THOSE BACTERIAL 262 00:12:27,920 --> 00:12:29,760 GROUPS, THE SIGHIA KNOW BACTERIA 263 00:12:29,760 --> 00:12:34,120 USES WATER AS ELECTRON PRODUCES 264 00:12:34,120 --> 00:12:36,080 OXYGEN AS BY-PRODUCT. THE REST 265 00:12:36,080 --> 00:12:38,920 USE ELECTRON DONORS THAT RANGE 266 00:12:38,920 --> 00:12:41,400 FROM HYDROGEN GAS TO HYDROGEN 267 00:12:41,400 --> 00:12:42,920 SULFIDE, THE FAIREST IRON AND 268 00:12:42,920 --> 00:12:44,280 NUMBER OF OTHER THINGS AND THEY 269 00:12:44,280 --> 00:12:49,920 DO NOT GIVE OFF OXYGEN. 270 00:12:49,920 --> 00:12:52,520 RESPONSE. SO THERE IS A WHOLE 271 00:12:52,520 --> 00:12:54,880 WORLD OF PRIMARY PRODUCTION 272 00:12:54,880 --> 00:12:55,760 FUNDAMENTALLY DISTINCT FROM THE 273 00:12:55,760 --> 00:12:57,840 ONE WE KNOW IN PLANTS. THE SAME 274 00:12:57,840 --> 00:13:00,600 IS TRUE FOR RESERVATION. I LIKE 275 00:13:00,600 --> 00:13:03,400 THIS DIAGRAM ON THE RIGHT BY MY 276 00:13:03,400 --> 00:13:04,920 FRIEND KEN NIELSEN FROM A REVIEW 277 00:13:04,920 --> 00:13:06,280 PAPER SOME YEARS BACK. WHAT IT 278 00:13:06,280 --> 00:13:09,520 SIMPLY SHOWS IS ON THE LEFT-HAND 279 00:13:09,520 --> 00:13:11,920 SIDE FUELS USED IN METABOLISM IN 280 00:13:11,920 --> 00:13:14,640 THE RIGHT HAND SIDE OXIDANTS 281 00:13:14,640 --> 00:13:16,520 ALONG THE ELECTRONEGATIVITY 282 00:13:16,520 --> 00:13:21,040 CREATING IT AND AS KEN'S ARROWS 283 00:13:21,040 --> 00:13:24,320 SHOW, THE CARTOONS IF YOU GO -- 284 00:13:24,320 --> 00:13:26,560 CONNECT THE FUEL WITH THE 285 00:13:26,560 --> 00:13:28,080 OXIDANT IN A DIRECTION THAT GOES 286 00:13:28,080 --> 00:13:30,640 DOWNHILL ON THIS DIAGRAM IT 287 00:13:30,640 --> 00:13:32,400 YIELDS ENERGY AND CAN SUPPORT 288 00:13:32,400 --> 00:13:37,480 METABOLISM. SO CLEARLY THE MOST 289 00:13:37,480 --> 00:13:38,520 OXIDIZED OXIDANT WE CAN DEAL 290 00:13:38,520 --> 00:13:41,160 WITH HERE IS OXYGEN GAS, THAT 291 00:13:41,160 --> 00:13:46,640 YIELDS THE MOST ENERGY IN THE 292 00:13:46,640 --> 00:13:51,080 RESPIRATION. BASICALLY ALL 293 00:13:51,080 --> 00:13:53,640 EUKARYOTS RESPIRE AEROBICALLY, 294 00:13:53,640 --> 00:13:54,960 WITH FEW EXCEPTIONS BUT THAT IS 295 00:13:54,960 --> 00:13:58,600 WHAT THEY DO. MANY BACTERIA AND 296 00:13:58,600 --> 00:13:59,880 -- DO AS WELL. ON THE OTHER HAND 297 00:13:59,880 --> 00:14:02,720 IF YOU LOOK AT THAT DIAGRAM, 298 00:14:02,720 --> 00:14:04,720 OXYGEN GAS IS NOT THE ONLY 299 00:14:04,720 --> 00:14:06,400 OXIDANT THAT CAN METABOLIZE 300 00:14:06,400 --> 00:14:09,720 ORGANIC MOLECULES. THERE IS 301 00:14:09,720 --> 00:14:11,200 NITRATE, THERE IS MANGANESE AND 302 00:14:11,200 --> 00:14:14,840 IRON OXIDES. SULFATE, AND THIS 303 00:14:14,840 --> 00:14:16,880 IS ALMOST EXCLUSIVELY THE 304 00:14:16,880 --> 00:14:22,240 PROVINCE OF BACTERIA AND ARCIA. 305 00:14:22,240 --> 00:14:24,440 THERE IS ONE KNOWN IN THE OCEANS 306 00:14:24,440 --> 00:14:26,640 CAPABLE OF NITRATE RESPIRATION 307 00:14:26,640 --> 00:14:30,720 AND THAT NOT SURPRISINGLY USES A 308 00:14:30,720 --> 00:14:31,880 PHYSIOLONGCAL PATHWAY THAT WAS 309 00:14:31,880 --> 00:14:34,880 INHERITED BY LATERAL TRANSFER 310 00:14:34,880 --> 00:14:36,760 FROM A NITRATE RESPIRING 311 00:14:36,760 --> 00:14:40,520 BACTERIA. YOU WILL ALSO NOTICE 312 00:14:40,520 --> 00:14:43,600 IN THE DIAGRAM THAT YOU CAN 313 00:14:43,600 --> 00:14:47,240 CONNECT INORGANIC FUELS TO 314 00:14:47,240 --> 00:14:49,440 OXIDANTS AS WELL AND THAT GIVES 315 00:14:49,440 --> 00:14:51,680 RISE TO METABOLISM ONLY KNOWN IN 316 00:14:51,680 --> 00:14:54,400 BACTERIA AND ARCIA WHICH IS 317 00:14:54,400 --> 00:14:56,760 CHEMO SYNTHESIS. SO THERE IS A 318 00:14:56,760 --> 00:14:59,240 MUCH BROADER RANGE OF 319 00:14:59,240 --> 00:15:01,760 METABOLISMS AMONG MICROBES. AND 320 00:15:01,760 --> 00:15:04,000 IF YOU JUST SUMMARIZE THE CARBON 321 00:15:04,000 --> 00:15:07,240 CYCLE THEN WITH THIS SERIES OF 322 00:15:07,240 --> 00:15:09,800 RINGS, ON THE OUTER RING IS 323 00:15:09,800 --> 00:15:11,800 OXYGENIC PHOTOSYNTHESIS AND 324 00:15:11,800 --> 00:15:12,560 AEROBIC RESERVATION, THE STUFF 325 00:15:12,560 --> 00:15:17,080 OF PLANTS AND ANIMALS ALSO OF 326 00:15:17,080 --> 00:15:19,240 ESSENTIALLY ALL PROTUS AND MANY 327 00:15:19,240 --> 00:15:26,640 BACTERIA AND ARCHIA, TESTIMONY 328 00:15:26,640 --> 00:15:29,360 ANTIOXIDANT RESPIRATION, THE 329 00:15:29,360 --> 00:15:34,320 PROVINCE OF BACTERIA AND 330 00:15:34,320 --> 00:15:36,760 ARCHAEA, AND I PUT FERMENTATION 331 00:15:36,760 --> 00:15:39,720 IN THERE YES, WE ALL FOR MEANT 332 00:15:39,720 --> 00:15:43,560 AS AN AUXILLARY METABOLISM BUT 333 00:15:43,560 --> 00:15:46,320 FEW EUKARYOTS DO IT WELL THESE 334 00:15:46,320 --> 00:15:46,960 BEING THE GREAT EXCEPTION. IF 335 00:15:46,960 --> 00:15:50,160 YOU LOOK AT THE VARIOUS 336 00:15:50,160 --> 00:15:51,880 METABOLIC PATHWAYS OF 337 00:15:51,880 --> 00:15:53,840 FERMENTATION, THEY ARE MUCH MORE 338 00:15:53,840 --> 00:15:55,800 EXTENSIVE AND DIVERSE IN 339 00:15:55,800 --> 00:16:01,120 BACTERIA AND ACCHEAE THAN 340 00:16:01,120 --> 00:16:03,360 EUKARYOTS. IT IS IN SOME WAYS A 341 00:16:03,360 --> 00:16:05,520 BACTERIAL WORLD. IT BECOMES MORE 342 00:16:05,520 --> 00:16:07,080 WHEN YOU CONSIDER ENERGY 343 00:16:07,080 --> 00:16:10,440 METABOLISM IN EUKARYOTIC CELLS 344 00:16:10,440 --> 00:16:12,120 INCLUDING YOUR OWN. AS MANY OF 345 00:16:12,120 --> 00:16:16,000 YOU KNOW, THE MAJOR ENERGETIC 346 00:16:16,000 --> 00:16:17,240 ORGANELLES IN YOUR OWN CELLS 347 00:16:17,240 --> 00:16:19,160 WERE DERIVED FROM ONCE FREE 348 00:16:19,160 --> 00:16:22,680 LIVING BACTERIA. SO ON THE LEFT 349 00:16:22,680 --> 00:16:26,120 IS A FAIRLY RECENT MOLECULAR 350 00:16:26,120 --> 00:16:28,000 PHYLOGENY OF ALPHA 351 00:16:28,000 --> 00:16:29,240 PROTEOBACTERIA. THERE IS TWO 352 00:16:29,240 --> 00:16:31,640 THINGS TO NOTICE IN HERE BOTH 353 00:16:31,640 --> 00:16:33,960 WORTH MENTIONING. FIRST IS ALL 354 00:16:33,960 --> 00:16:36,200 OF THE CLADES THAT ARE INCLUDED 355 00:16:36,200 --> 00:16:38,520 IN THIS DIAGRAM ARE OF ORGANISMS 356 00:16:38,520 --> 00:16:40,800 THAT ARE KNOWN ONLY BY META 357 00:16:40,800 --> 00:16:43,200 GENOMIC ANALYSIS. THAT IS WE 358 00:16:43,200 --> 00:16:45,480 HAVE NO IDEA WHAT THE ORGANISMS 359 00:16:45,480 --> 00:16:48,880 AS ORGANISMS ARE LIVE, WE SIMPLY 360 00:16:48,880 --> 00:16:50,880 KNOW THEY ARE GENOMES PLACED IN 361 00:16:50,880 --> 00:16:52,520 THAT PARTICULAR POSITION IN THE 362 00:16:52,520 --> 00:16:55,040 PHYLOGENY. IT IS FAIR TO SAY 363 00:16:55,040 --> 00:16:57,720 UNTIL THE DAWN OF ENVIRONMENTAL 364 00:16:57,720 --> 00:17:00,400 SEQUENCING, WE HAD NO IDEA OF 365 00:17:00,400 --> 00:17:02,000 THE TRUE DIVERSITY OF MICROBES 366 00:17:02,000 --> 00:17:04,040 IN THIS WORLD. WE ARE STILL 367 00:17:04,040 --> 00:17:04,840 LEARNING ABOUT THAT DIVERSITY 368 00:17:04,840 --> 00:17:08,680 BUT RATHER THAN BEING IS 369 00:17:08,680 --> 00:17:10,200 SOMETHING LIKE 2000 BACTERIAL 370 00:17:10,200 --> 00:17:13,280 SPECIES DESCRIBED FROM PURE 371 00:17:13,280 --> 00:17:16,160 CULTURES, BY SAY 1970, WE NOW 372 00:17:16,160 --> 00:17:17,440 KNOW THAT -- THE RIGHT NUMBER IS 373 00:17:17,440 --> 00:17:19,440 IN THE MILLIONS. ALSO IF YOU 374 00:17:19,440 --> 00:17:22,600 LOOK ON THAT DIAGRAM, THE BLUE 375 00:17:22,600 --> 00:17:24,560 CLADE YOU SEE NEAR THE BASE IS 376 00:17:24,560 --> 00:17:26,240 WHERE MITOCHONDRIA FIT IN. SO 377 00:17:26,240 --> 00:17:28,640 THAT MITOCHONDRIA CLEARLY ARE 378 00:17:28,640 --> 00:17:31,280 DERIVED FROM ONCE FREE LIVING 379 00:17:31,280 --> 00:17:34,880 PROTEOBACTERIA THAT ENDED IN 380 00:17:34,880 --> 00:17:36,440 SYMBIOSIS WITH A HOST AND WAS 381 00:17:36,440 --> 00:17:37,440 REDUCED TO METHOD BOLLIC 382 00:17:37,440 --> 00:17:42,080 SLAVERY. ON THE RIGHT WE SEE A 383 00:17:42,080 --> 00:17:45,080 SIMILAR DIAGRAM FOR CHLOROPLAST. 384 00:17:45,080 --> 00:17:47,400 THE MIDDLE CLADES THERE,S 385 00:17:47,400 --> 00:17:51,400 DESIGNATED ARCHIPLASTINS ARE THE 386 00:17:51,400 --> 00:17:54,920 PLACEMENT FOR MOLECULAR 387 00:17:54,920 --> 00:17:57,160 PHYLOGENY OF CHLOROPLASTS IN RED 388 00:17:57,160 --> 00:17:58,520 GREEN AND (INAUDIBLE) ALGAE, 389 00:17:58,520 --> 00:18:00,520 LAND PLANTS THAT BASICALLY GREEN 390 00:18:00,520 --> 00:18:04,200 ALGAE WITH A MASTERS DEGREE. AND 391 00:18:04,200 --> 00:18:07,840 VERY CLEARLY THEY -- THOSE ARE 392 00:18:07,840 --> 00:18:09,200 DERIVED FROM ONCE FREE LIVING 393 00:18:09,200 --> 00:18:13,440 SIGHIA KNOW BACTERIA. SO -- 394 00:18:13,440 --> 00:18:14,040 CYANO BACK TIER Y THE BASIC 395 00:18:14,040 --> 00:18:15,560 ENERGY EUKARYOTS IS 396 00:18:15,560 --> 00:18:16,480 FUNDAMENTALLY BACTERIAL IN 397 00:18:16,480 --> 00:18:19,320 NATURE. THAT IS THE CARBON 398 00:18:19,320 --> 00:18:21,800 CYCLE. JUST A FEW WORDS ABOUT 399 00:18:21,800 --> 00:18:23,720 NITROGEN AND SULFUR, TO SEE HOW 400 00:18:23,720 --> 00:18:28,360 THEY FIT INTO THIS PICTURE. WE 401 00:18:28,360 --> 00:18:31,320 ALL KNOW EVERY ORGANISM REQUIRES 402 00:18:31,320 --> 00:18:32,920 NITROGEN, IT IS PROTEINS AND 403 00:18:32,920 --> 00:18:34,960 NUCLEIC ACIDS AND NUMBER OF 404 00:18:34,960 --> 00:18:37,360 OTHER MOLECULES. PRIMARY 405 00:18:37,360 --> 00:18:40,320 PRODUCERS GET NITROGEN THEY NEED 406 00:18:40,320 --> 00:18:42,880 FOR SYNTHESIS FROM EITHER 407 00:18:42,880 --> 00:18:45,640 NITRATE OR AMMONIA AND SOILS OR 408 00:18:45,640 --> 00:18:49,400 WATER. THEN IT PASSES THROUGH A 409 00:18:49,400 --> 00:18:52,880 FOOD CHAIN, AS HETERO TROVE 410 00:18:52,880 --> 00:18:54,480 PHOTO SYNTHESIZERS THEN GO ON 411 00:18:54,480 --> 00:18:57,840 FROM THERE. THROUGH 412 00:18:57,840 --> 00:18:59,840 DECOMPOSITION THEN AMMONIA IS 413 00:18:59,840 --> 00:19:02,320 RETURN TODS THE ENVIRONMENT, 414 00:19:02,320 --> 00:19:08,960 PROCESS CALLED (INDISCERNIBLE) 415 00:19:08,960 --> 00:19:14,600 THAT IS DEACETYLATED BUT THERE'S 416 00:19:14,600 --> 00:19:17,160 A NUMBER OF CHEMO SYNTHETIC 417 00:19:17,160 --> 00:19:19,640 BACTERIA CALLED NITRO FIRES THAT 418 00:19:19,640 --> 00:19:22,360 WILL OXIDIZE PNEUMONIA TO NIGH 419 00:19:22,360 --> 00:19:23,120 TRIED AND THEN TO NITRATED. 420 00:19:23,120 --> 00:19:25,520 USUALLY DONE BY TWO SEPARATE 421 00:19:25,520 --> 00:19:26,600 ECOLOGICALLY CLOSELY RELATED 422 00:19:26,600 --> 00:19:29,040 SPECIES. AND THEN THAT NITRATE 423 00:19:29,040 --> 00:19:30,640 CAN ACTUALLY BE ASSIMILATED BY 424 00:19:30,640 --> 00:19:33,720 PRIMARY PRODUCERS AS WELL BUT 425 00:19:33,720 --> 00:19:35,360 AGAIN THERE IS COMPETITION IN 426 00:19:35,360 --> 00:19:36,200 LOW OXYGEN ENVIRONMENT BECAUSE 427 00:19:36,200 --> 00:19:40,840 THE NITRATE IS USED FOR 428 00:19:40,840 --> 00:19:49,160 RESPIRATION. A PROCESS CALLED 429 00:19:49,160 --> 00:19:50,080 DENITROGENATION, RETURN FROM THE 430 00:19:50,080 --> 00:19:51,360 ATMOSPHERE. THERE IS A SECOND 431 00:19:51,360 --> 00:19:53,360 PROCESS BACK TO AMMONIA 432 00:19:53,360 --> 00:19:54,400 DISCOVERED ONLY A FEW DECADES 433 00:19:54,400 --> 00:20:00,400 AGO. CALLED PANAMOM, AN AEROBIC 434 00:20:00,400 --> 00:20:03,520 AMMONIA OXIDATION WHERE YOU HAVE 435 00:20:03,520 --> 00:20:05,760 AMMONIA REACT WITH NITRITE 436 00:20:05,760 --> 00:20:06,920 YIELDING ENERGY AND AGAIN 437 00:20:06,920 --> 00:20:08,400 RETURNING NITROGEN TO THE 438 00:20:08,400 --> 00:20:11,400 ATMOSPHERE AS NITROGEN GAS. AS 439 00:20:11,400 --> 00:20:13,480 I JUST EXPLAINED, THIS IS A 440 00:20:13,480 --> 00:20:15,920 PROCESS THAT WILL RUN OUTS OF 441 00:20:15,920 --> 00:20:18,880 STEAM. BECAUSE IT IS A LEAKY 442 00:20:18,880 --> 00:20:21,240 PROCESS WHICH KEEPS RETURNING 443 00:20:21,240 --> 00:20:23,840 BIOAVAILABLE NITROGEN TO THE 444 00:20:23,840 --> 00:20:26,560 ATMOSPHERE. THE REASON THAT 445 00:20:26,560 --> 00:20:27,960 ECOSYSTEMS ARE ABLE TO BE 446 00:20:27,960 --> 00:20:29,040 SUSTAINED OVER LONG PERIODS OF 447 00:20:29,040 --> 00:20:30,920 TIME IS THERE IS ONE MORE 448 00:20:30,920 --> 00:20:33,280 PROCESS AGAIN EXCLUSIVELY 449 00:20:33,280 --> 00:20:36,920 MICROBIAL, CALLED NITROGEN 450 00:20:36,920 --> 00:20:39,920 FIXATION IN WHICH MICROBES AND 451 00:20:39,920 --> 00:20:42,120 ENERGETICALLY EXPENSIVE PROCESS 452 00:20:42,120 --> 00:20:44,760 BUT THEY CAN REDUCE NITROGEN GAS 453 00:20:44,760 --> 00:20:47,960 TO AMMONIA AND THAT IS PROBABLY 454 00:20:47,960 --> 00:20:50,160 NEXT TO PHOTOSYNTHESIS THE MOST 455 00:20:50,160 --> 00:20:53,000 IMPORTANT METABOLISM EVER 456 00:20:53,000 --> 00:20:55,200 INVOLVED BECAUSE IT WITH 457 00:20:55,200 --> 00:20:57,000 PHOTOSYNTHESIS ALLOWS ECOSYSTEMS 458 00:20:57,000 --> 00:20:58,400 TO BE MAINTAIN FOR LONG 459 00:20:58,400 --> 00:21:05,480 INTERVALS OF TIME. YOU MIGHT SAY 460 00:21:05,480 --> 00:21:07,480 WELL ALL THESE BACTERIA BUT 461 00:21:07,480 --> 00:21:10,200 DON'T SOYBEANS FIX NITROGEN, 462 00:21:10,200 --> 00:21:15,800 FARMERS FIX SOYBEANS IN CROP 463 00:21:15,800 --> 00:21:19,760 ROTATION. BIOAVAILABLE, THAT IS 464 00:21:19,760 --> 00:21:21,320 HALF RIGHT. SOYBEANS ARE 465 00:21:21,320 --> 00:21:26,440 INVOLVED IN THIS PROCESS, ROOTS 466 00:21:26,440 --> 00:21:30,040 OF SOY BEAN WHAT YOU SEE ARE NO 467 00:21:30,040 --> 00:21:33,120 DUALS ARE PLACES THEY HARBOR 468 00:21:33,120 --> 00:21:34,720 SYMBIOTIC NITROGEN FIXING 469 00:21:34,720 --> 00:21:37,160 BACTERBACTERIA. SO SOYBEANS THES 470 00:21:37,160 --> 00:21:38,880 CAN'T FIX NITROGEN BETTER THAN 471 00:21:38,880 --> 00:21:44,200 YOU AND I CAN. BUT WITH THESE SY 472 00:21:44,200 --> 00:21:45,520 MANYMBIOTS THEY PLAY A ROLE IN 473 00:21:45,520 --> 00:21:49,160 THE PROCESS. FINALLY SULFUR, 474 00:21:49,160 --> 00:21:51,400 AGAIN TWO AMINO ACIDS USE IT, 475 00:21:51,400 --> 00:21:52,960 THERE'S HUNDREDS OF ENZYMES THAT 476 00:21:52,960 --> 00:21:55,520 HAVE SULFUR AS A CO-FACTOR, THAT 477 00:21:55,520 --> 00:21:58,000 IS PRESENT IN WIDE VARIETY OF 478 00:21:58,000 --> 00:22:02,440 BIOMOLECULES. ONCE AGAIN SULFUR 479 00:22:02,440 --> 00:22:04,160 ENTERS THE BIOLOGICAL CYCLE BY 480 00:22:04,160 --> 00:22:05,960 UPTAKE OF SULFATE FROM THE 481 00:22:05,960 --> 00:22:08,440 ENVIRONMENT BY PRIMARY 482 00:22:08,440 --> 00:22:10,040 PRODUCERS. IT PASSES THROUGH 483 00:22:10,040 --> 00:22:12,200 FOOD GRABS AND THROUGH 484 00:22:12,200 --> 00:22:14,920 DECOMPOSITION RETURNED TO THE 485 00:22:14,920 --> 00:22:18,400 ENVIRONMENT AS HYDROGEN SULFIDE. 486 00:22:18,400 --> 00:22:19,960 THEN MUCH OF THAT HYDROGEN 487 00:22:19,960 --> 00:22:21,480 SULFIDE GOES INTO ENERGY 488 00:22:21,480 --> 00:22:23,600 METABOLISM. AS AN ELECTRON DONOR 489 00:22:23,600 --> 00:22:28,320 FOR PHOTO SYNTHETIC BACTERIA OR 490 00:22:28,320 --> 00:22:30,320 CHEMO ATROPHIC MICROBES YIELDING 491 00:22:30,320 --> 00:22:32,000 SULFATE AS A PRODUCTS AND THAT 492 00:22:32,000 --> 00:22:33,800 SULFATE AGAIN WHILE IT CAN BE 493 00:22:33,800 --> 00:22:35,720 ASSIMILATED BY PRIMARY 494 00:22:35,720 --> 00:22:37,040 PRODUCERS, MUCH OF THE SULFATE 495 00:22:37,040 --> 00:22:40,800 IS ACTUALLY USED IN RESPIRATION. 496 00:22:40,800 --> 00:22:41,640 SOMETHING CALLED SULFATE 497 00:22:41,640 --> 00:22:43,760 REDUCTION. IT IS ESTIMATED THAT 498 00:22:43,760 --> 00:22:46,440 AS MUCH AS 50% OF ORGANIC MATTER 499 00:22:46,440 --> 00:22:49,080 THAT LANDS ON THE SEA FLOOR IS 500 00:22:49,080 --> 00:22:50,280 REMINERALIZED VIA SULFATE 501 00:22:50,280 --> 00:22:52,280 REDUCTION. IT IS AN IMPORTANT 502 00:22:52,280 --> 00:22:53,920 PROCESS. AGAIN AS IN THE NIGH 503 00:22:53,920 --> 00:22:56,360 THROW GENERAL CYCLE ALL HEAVY 504 00:22:56,360 --> 00:22:59,120 LIFTERS ARE BACTERIA AND 505 00:22:59,120 --> 00:23:01,520 ARCHAEA. ONCE AGAIN YOU MIGHT 506 00:23:01,520 --> 00:23:05,320 SAY I REMEMBER READING ABOUT 507 00:23:05,320 --> 00:23:06,880 THESE INTERESTING WORM THAT LIVE 508 00:23:06,880 --> 00:23:09,320 IN HYDRO THERMAL VENTS AND MID 509 00:23:09,320 --> 00:23:14,320 OCEAN RIDGES THEY FEED BY SULFUR 510 00:23:14,320 --> 00:23:14,920 CHEMOAUTOTROPHY, THE WORMS YOU 511 00:23:14,920 --> 00:23:16,920 LOOK AT ARE REMARKABLE BECAUSE 512 00:23:16,920 --> 00:23:19,600 THEY HAVE RED PAL PES AT THE 513 00:23:19,600 --> 00:23:22,560 ANTERIOR END OF THE BODIES THEY 514 00:23:22,560 --> 00:23:24,360 BASICALLY FARM CHEMOSYNTHETIC 515 00:23:24,360 --> 00:23:26,800 SULFUR BACTERIA. SO AGAIN, THEY 516 00:23:26,800 --> 00:23:29,240 ARE ONLY ABLE TO TAKE ADVANTAGE 517 00:23:29,240 --> 00:23:32,040 OF THIS MICROBIAL PROCESS 518 00:23:32,040 --> 00:23:35,360 THROUGH SYMBIOSIS. THEN IT GETS 519 00:23:35,360 --> 00:23:38,360 EVEN MORE INTERESTING THAT IT 520 00:23:38,360 --> 00:23:41,040 TURNS OUT INTIMATE BIOLOGICAL 521 00:23:41,040 --> 00:23:42,560 RELATIONSHIPS BETWEEN MICROBES 522 00:23:42,560 --> 00:23:44,240 AND COMPLEX MULTI-CELLULAR 523 00:23:44,240 --> 00:23:47,360 ORGANISMS ARE UBIQUITOUS. IT IS 524 00:23:47,360 --> 00:23:48,800 PRETTY CLEAR YOUR OWN BODY 525 00:23:48,800 --> 00:23:50,320 CONTAINS MORE BACTERIAL CELLS 526 00:23:50,320 --> 00:23:54,600 THAN IT DOES HUMAN CELLS. 527 00:23:54,600 --> 00:23:55,800 PROBABLY SOME PEOPLE WHO ARE 528 00:23:55,800 --> 00:23:57,680 LISTENING ARE ACTUALLY WORKING 529 00:23:57,680 --> 00:24:03,640 ON THINGS LIKE YOUR GUT BIOME 530 00:24:03,640 --> 00:24:04,920 WHICH CLEARLY AS WE LEARN IS 531 00:24:04,920 --> 00:24:06,160 INTEGRAL TO OUR OWN DEVELOPMENT 532 00:24:06,160 --> 00:24:09,640 TO THE IMMUNE SYSTEM AND HEALTH 533 00:24:09,640 --> 00:24:11,560 ONCE AGAIN, BACTERIA ARE 534 00:24:11,560 --> 00:24:14,680 FUNDAMENTAL TO ALL OF THIS. SO 535 00:24:14,680 --> 00:24:18,560 LET'S SWITCH GEARS L GEARS A LIT 536 00:24:18,560 --> 00:24:20,240 AND LOOK AT PERSPECTIVES ON 537 00:24:20,240 --> 00:24:23,160 BIOLOGICAL WORLD. I LOVE THIS 538 00:24:23,160 --> 00:24:24,920 DIAGRAM IN THE UPPER LEFT FROM 539 00:24:24,920 --> 00:24:28,880 THE LAB OF RON MELOUGH FROM THE 540 00:24:28,880 --> 00:24:31,120 INSTITUTE IN ISRAEL AND RON AND 541 00:24:31,120 --> 00:24:32,400 COLLEAGUE AS FEW YEARS AGO TRIED 542 00:24:32,400 --> 00:24:34,000 TO QUANTIFY THE BIOMASS OF 543 00:24:34,000 --> 00:24:35,840 DIFFERENT KINDS OF ORGANISMS ON 544 00:24:35,840 --> 00:24:39,720 THIS PLANET. WHAT YOU SEE IS 545 00:24:39,720 --> 00:24:43,920 RESULTS OF THEIR LABORS, IN THIS 546 00:24:43,920 --> 00:24:46,120 MOST BIOMASS IS IN THE FORM OF 547 00:24:46,120 --> 00:24:48,320 PLANTS WITH BACTERIA SECOND AND 548 00:24:48,320 --> 00:24:49,880 ONLY THAT LITTLE RED BOX IN THE 549 00:24:49,880 --> 00:24:54,040 CORNER MUCH LESS THAN 1% OF 550 00:24:54,040 --> 00:24:57,160 BIOMASS DO YOU FIND ANIMALS. IT 551 00:24:57,160 --> 00:25:00,080 TURNS OUT THAT THE PLANTS CHEAT 552 00:25:00,080 --> 00:25:03,440 IN THE SENSE THAT IF YOU GO 553 00:25:03,440 --> 00:25:05,360 OUTSIDE AND LOOK CAREFULLY AT A 554 00:25:05,360 --> 00:25:06,320 TREE OURSELF YOUR OFFICE, YOU 555 00:25:06,320 --> 00:25:09,200 WILL FIND THAT MORE THAN 90% OF 556 00:25:09,200 --> 00:25:10,920 THE MASS OFNA TREE IS NON-LIVING 557 00:25:10,920 --> 00:25:14,080 CELLS BASICALLY WOODS. SO IF 558 00:25:14,080 --> 00:25:18,880 YOU ONLY TAKE LIVING TISSUES OF 559 00:25:18,880 --> 00:25:21,640 PLANTS, IN FACT BACTERIA TURN 560 00:25:21,640 --> 00:25:23,880 OUT MOST ABUNDANT BIOMASS 561 00:25:23,880 --> 00:25:28,440 ORGANISMS ON THE PLANET. IF YOU 562 00:25:28,440 --> 00:25:30,440 LOOK AT THE DIAGRAM BELOW THAT 563 00:25:30,440 --> 00:25:33,280 THAT IS UNIVERSAL PHYLOGENY. IT 564 00:25:33,280 --> 00:25:36,920 SHOWS THE THREE MAJOR GROUPS OF 565 00:25:36,920 --> 00:25:38,800 ORGASMS EUKARYOTS WHICH Y'ALL 566 00:25:38,800 --> 00:25:41,960 KNOW BACTERIA, AS ADVERTISED IN 567 00:25:41,960 --> 00:25:46,480 THE ARCHEA GROUP RECOGNIZED AS 568 00:25:46,480 --> 00:25:52,200 SEPARATE FROM BACTERIA IN 1977. 569 00:25:52,200 --> 00:25:53,800 THIS DIAGRAM NEEDS UPDATING IN 570 00:25:53,800 --> 00:25:55,320 THE SENSE THAT RATHER THAN 571 00:25:55,320 --> 00:25:57,040 SEEING EUKARYOTS AS A SISTER 572 00:25:57,040 --> 00:26:01,640 GROUP TO THE ARCHAEA IT'S BECOME 573 00:26:01,640 --> 00:26:04,080 INCREASINGLY CLEAR THE 574 00:26:04,080 --> 00:26:05,440 EUKARYOTIC CELL ITSELF 575 00:26:05,440 --> 00:26:07,360 REPRESENTS THE PRODUCT OF THE 576 00:26:07,360 --> 00:26:09,920 MERGER BETWEEN ARCHEON FROM A 577 00:26:09,920 --> 00:26:12,880 GROUP OF ARCHEA ONLY DISCOVERED 578 00:26:12,880 --> 00:26:16,760 IN 2015,S AND BACTERIA. SO 579 00:26:16,760 --> 00:26:18,360 EUKARYOTS ARE IN SOME SENSE A 580 00:26:18,360 --> 00:26:20,960 COMPOUND ORGANISM. BUT THE ONE 581 00:26:20,960 --> 00:26:22,280 THING, THE REASON I SHOW THIS 582 00:26:22,280 --> 00:26:25,040 DIAGRAM IS TO MAKE IT CLEAR ONE 583 00:26:25,040 --> 00:26:26,960 THING EVERYBODY AGREES ON THESE 584 00:26:26,960 --> 00:26:28,400 KINDS OF PHYLOGENIES, THAT IS 585 00:26:28,400 --> 00:26:34,480 THAT ANIMALS ARE SIMPLY ONE 586 00:26:34,480 --> 00:26:38,800 DISTAL TWIG ON ONE BRANCH OF THE 587 00:26:38,800 --> 00:26:42,360 TREE THE DEEP HISTORY IF IT IS 588 00:26:42,360 --> 00:26:44,240 LARGELY MICROBIAL. THAT LEADS US 589 00:26:44,240 --> 00:26:45,520 TO THE DIAGRAM ON THE RIGHT 590 00:26:45,520 --> 00:26:48,080 WHICH IS SIMPLY A TIME AXIS OF 591 00:26:48,080 --> 00:26:50,640 EARTH HISTORY. THE OLDEST 592 00:26:50,640 --> 00:26:52,880 EVIDENCE WE HAVE OF ANIMALS ON 593 00:26:52,880 --> 00:26:57,200 THIS PLANET IS ABOUT 575 MILLION 594 00:26:57,200 --> 00:26:59,560 YEARS OLD. THE EARTH ITSELF IS 595 00:26:59,560 --> 00:27:03,000 MORE THAN 4 1/2 BILLION YEARS 596 00:27:03,000 --> 00:27:06,240 OLD AND SO THE QUESTION ARISES 597 00:27:06,240 --> 00:27:07,840 WHAT PRECEDESSED THOSE ANIMALS 598 00:27:07,840 --> 00:27:09,800 IN THEIR HISTORY. AND THE 599 00:27:09,800 --> 00:27:11,280 INFERENCE FROM PHYLOGENY WOULD 600 00:27:11,280 --> 00:27:14,680 BE THERE COULD BE A LONG HISTORY 601 00:27:14,680 --> 00:27:16,480 OF LIFE THAT IS LARGELY 602 00:27:16,480 --> 00:27:25,280 MICROBIAL. THE EMPIRICAL YES 603 00:27:25,280 --> 00:27:27,600 QUESTION BECOMES CAN WE FINDS 604 00:27:27,600 --> 00:27:29,480 INTRACTABLE RECORD OF THE 605 00:27:29,480 --> 00:27:30,840 EARLIER MICROBIAL EVOLUTION 606 00:27:30,840 --> 00:27:33,000 PRESERVED IN SEDIMENTARY ROCKS. 607 00:27:33,000 --> 00:27:34,200 WHAT WE ARE LOOKING AT HERE IS A 608 00:27:34,200 --> 00:27:36,440 PLACE THAT I WORK AT FOR NUMBER 609 00:27:36,440 --> 00:27:38,840 OF YEARS WHEN I WAS YOUNGER AND 610 00:27:38,840 --> 00:27:41,440 FITTER, THESE ARE ROCKS BETWEEN 611 00:27:41,440 --> 00:27:45,200 750 AND 800 MILLION YEARS OLD. 612 00:27:45,200 --> 00:27:47,240 THAT ARE NOW PROPPING ON THE 613 00:27:47,240 --> 00:27:50,000 ARCTIC ISLAND HALFWAY BETWEEN 614 00:27:50,000 --> 00:27:52,120 NORTHERN TIP OF NORWAY AND THE 615 00:27:52,120 --> 00:27:53,560 NORTH POLE, TO GIVE YOU A SENSE 616 00:27:53,560 --> 00:27:55,280 OF DIMENSIONS HERE, WE STUCK THE 617 00:27:55,280 --> 00:27:57,480 EMPIRE STATE BUILDING AT THE 618 00:27:57,480 --> 00:28:03,400 BASE OF THAT CLIFF ITS RAIDS OWE 619 00:28:03,400 --> 00:28:04,240 TOWER OUTSIDE JUST PEEK OVER THE 620 00:28:04,240 --> 00:28:06,200 TOP OF THE HILL SO IT IS A 621 00:28:06,200 --> 00:28:08,080 REMARKABLY EXPOSED RECORD OF 622 00:28:08,080 --> 00:28:09,440 VERY WELL PRESERVED SEDIMENTARY 623 00:28:09,440 --> 00:28:11,400 ROCKS. SO THE QUESTION THEN 624 00:28:11,400 --> 00:28:15,480 BECOMES, DO THESE ROCKS CONTAIN 625 00:28:15,480 --> 00:28:22,040 ANY EVIDENCE OF MICROBIAL LIFE. 626 00:28:22,040 --> 00:28:23,840 IF IF YOU LOOK AT THE UP PER 627 00:28:23,840 --> 00:28:28,960 RIGHT HAND PICTURE, THAT IS A 628 00:28:28,960 --> 00:28:35,560 LIMESTONE RELATIVE AND EWE SEE 629 00:28:35,560 --> 00:28:37,240 WAIVE LAMB NATIONS WHICH IS 630 00:28:37,240 --> 00:28:39,600 INTERRING BECAUSE IF YOU LOOK AT 631 00:28:39,600 --> 00:28:40,600 MODERN ENVIRONMENTS AND ASK HOW 632 00:28:40,600 --> 00:28:44,640 THOSE LAMB NATIONS FOR THEY FORM 633 00:28:44,640 --> 00:28:47,840 AS INTERACTION BETWEEN PHYSICAL 634 00:28:47,840 --> 00:28:55,080 SEDIMENTATION AND MICROBIAL BACK 635 00:28:55,080 --> 00:28:57,240 TIERDEDES, SO THAT TEXTURE TELLS 636 00:28:57,240 --> 00:28:59,720 US THIS EVIDENCE WAS CARPETED BY 637 00:28:59,720 --> 00:29:00,720 MICROBIAL COMMUNITIES AT THE 638 00:29:00,720 --> 00:29:03,560 TIME THE ROCKS FORMED. LOOK AT 639 00:29:03,560 --> 00:29:05,800 THE UPPER CENTER OF THE 640 00:29:05,800 --> 00:29:08,520 PHOTOGRAPH YOU WILL SEE THIS 641 00:29:08,520 --> 00:29:11,640 BENDING UPWARD, SOMETHING 642 00:29:11,640 --> 00:29:12,720 GEOLOGISTS CALL TP STRUCTURES 643 00:29:12,720 --> 00:29:14,480 THEY FORM IN A SPECIFIC WAY, 644 00:29:14,480 --> 00:29:18,200 THAT IS IN THE SUPER TIDAL ZONE 645 00:29:18,200 --> 00:29:21,360 WHERE THERE IS EVAPORATION YOU 646 00:29:21,360 --> 00:29:23,800 GET CALCIUM CARBONATE 647 00:29:23,800 --> 00:29:25,280 PRECIPITATE IN THE WATERINGS OF 648 00:29:25,280 --> 00:29:26,600 SEDIMENTS AND PRESSURE BUILDS UP 649 00:29:26,600 --> 00:29:30,520 AND CAUSES THEM TO BUCKLING BUCM 650 00:29:30,520 --> 00:29:32,680 THE TEXTURES OF ROCKS I CAN TELL 651 00:29:32,680 --> 00:29:35,760 YOU WHERE THEY WERE DEPOSITED 652 00:29:35,760 --> 00:29:37,160 AND THERE ARE MICROBIAL 653 00:29:37,160 --> 00:29:38,040 COMMUNITIES THERE AT THE TIME 654 00:29:38,040 --> 00:29:41,680 THEY FORM. IF YOU TAKE SOME OF 655 00:29:41,680 --> 00:29:44,000 THOSE GRAY CARBONATE ROCKS AND 656 00:29:44,000 --> 00:29:46,600 MAKE A SLICE UNDER MICROSCOPE 657 00:29:46,600 --> 00:29:50,040 YOU SEE INTERLOCKING CARBONATE 658 00:29:50,040 --> 00:29:54,640 CRYSTAL. IF YOU LOOK AT THOSE 659 00:29:54,640 --> 00:29:55,600 BLACK PANCAKE LIKE STRUCTURE, 660 00:29:55,600 --> 00:29:58,800 THOSE ARE NO DUALS OF SILICA -- 661 00:29:58,800 --> 00:30:01,760 NODULES OF SILICA QUARTERS THAT 662 00:30:01,760 --> 00:30:04,120 FORM WITHIN THE SEDIMENTS SOON 663 00:30:04,120 --> 00:30:06,560 AFTER THEY FORM. IF YOU TAKE 664 00:30:06,560 --> 00:30:08,080 THIN SECTIONS OF THOSE ROCKS AND 665 00:30:08,080 --> 00:30:09,800 LOOK AT THEM UNDER THE 666 00:30:09,800 --> 00:30:12,240 MICROSCOPE, WHAT YOU WILL SEE 667 00:30:12,240 --> 00:30:13,520 THE KIND OF THING IN THE PICTURE 668 00:30:13,520 --> 00:30:15,520 BELOW THERE. THOSE ARE 669 00:30:15,520 --> 00:30:18,480 MICROFOSSILS OF CYANO BACTERIA, 670 00:30:18,480 --> 00:30:21,400 EACH CELLS FOUR MICRONS IN 671 00:30:21,400 --> 00:30:22,400 DIAMETER, THAT TELLS US 672 00:30:22,400 --> 00:30:24,840 SOMETHING IMPORTANT. THE SMALL 673 00:30:24,840 --> 00:30:27,680 REALLY TINY BACTERIAL FOSSILS 674 00:30:27,680 --> 00:30:30,080 CAN AND ARE PRESERVED IN THE 675 00:30:30,080 --> 00:30:36,280 SEDIMENTARY ROCK RECORD. SOME 676 00:30:36,280 --> 00:30:37,160 CONTAIN ENOUGH INFORMATION TO 677 00:30:37,160 --> 00:30:39,120 TELL US SOMETHING OF BIOLOGICAL 678 00:30:39,120 --> 00:30:40,680 INTEREST. SO WHAT YOU ARE 679 00:30:40,680 --> 00:30:44,040 LOOKING AT HERE IS STALK FORMING 680 00:30:44,040 --> 00:30:45,320 ORGANISMS. THERE IS A SINGLE 681 00:30:45,320 --> 00:30:47,160 CELL IN THERE, THE CELL IS 682 00:30:47,160 --> 00:30:48,720 DECAYED SO ALL YOU CAN SEE IS 683 00:30:48,720 --> 00:30:51,400 JUST MICROBIAL GOO. BUT THERE 684 00:30:51,400 --> 00:30:57,440 WERE SERIES OF EXTRA CELLULAR 685 00:30:57,440 --> 00:30:58,600 ENVELOPES WHICH FORM A STALK IN 686 00:30:58,600 --> 00:31:00,480 THE DOWNWARD DIRECTION. THOSE 687 00:31:00,480 --> 00:31:02,360 CELLS CAN BE INDIVIDUALS OR AS 688 00:31:02,360 --> 00:31:04,080 YOU SEE ON THE RIGHT THEY CAN 689 00:31:04,080 --> 00:31:06,040 FORM CRUST US. AND WE KNOW 690 00:31:06,040 --> 00:31:10,200 ENOUGH THAT WE CAN CREATE A LIFE 691 00:31:10,200 --> 00:31:13,120 CYCLE FOR THIS ORGANISM THAT 692 00:31:13,120 --> 00:31:16,360 LIVES ON THE ORDER OF 750 TO 800 693 00:31:16,360 --> 00:31:21,000 MILLION YEARS AGO. IT TURNS OUT 694 00:31:21,000 --> 00:31:23,680 IF YOU GO TO THE BAHAMAS TODAY 695 00:31:23,680 --> 00:31:25,000 YOU CAN FIND PHYSICAL 696 00:31:25,000 --> 00:31:27,600 ENVIRONMENTS THAT ARE VERY 697 00:31:27,600 --> 00:31:28,600 SIMILAR TO THOSE INFERED FROM 698 00:31:28,600 --> 00:31:31,080 THE ROCKS WHICH THOSE FOSSILS 699 00:31:31,080 --> 00:31:33,040 WERE FOUND. WHEN YOU GO THERE, 700 00:31:33,040 --> 00:31:35,560 YOU WILL FIND THESE BLACK CRUSTS 701 00:31:35,560 --> 00:31:39,800 ON THE TO IT TIDAL FLAT SURFACE 702 00:31:39,800 --> 00:31:41,120 IF YOU LOOK IF THE BLACK CRUST 703 00:31:41,120 --> 00:31:44,400 THEY ARE MADE OF YANO BACTERIAL 704 00:31:44,400 --> 00:31:45,760 CELLS, SINGLE CELLS BUT WITH 705 00:31:45,760 --> 00:31:49,400 THESE ENVELOPES THAT GO FOR 706 00:31:49,400 --> 00:31:51,600 STALKS SO WHAT WE HAVE IS 707 00:31:51,600 --> 00:31:54,320 SEPARATED BY NEARLY 800 MILLION 708 00:31:54,320 --> 00:31:55,720 YEARS FOSSIL AND LIVING 709 00:31:55,720 --> 00:31:58,880 BACTERIAL POPULATIONS THAT ARE 710 00:31:58,880 --> 00:32:01,960 ALMOST IDENTICAL IN TERMS OF NOT 711 00:32:01,960 --> 00:32:03,160 ONLY ENVIRONMENTAL PREFERENCE 712 00:32:03,160 --> 00:32:06,240 BUT MORPHOLOGY AND LIFE CYCLE. 713 00:32:06,240 --> 00:32:10,760 IN FACT IF YOU LOOK IN DIFFERENT 714 00:32:10,760 --> 00:32:12,000 ENVIRONMENTS BY DIFFERENT 715 00:32:12,000 --> 00:32:13,200 SEDIMENTARY ROCKS IN THIS 716 00:32:13,200 --> 00:32:15,680 SUCCESSION WE FINE A VARIETY OF 717 00:32:15,680 --> 00:32:18,120 THINGS THAT ARE CYANO BACTERIA 718 00:32:18,120 --> 00:32:22,080 BUT ALSO EUKARYOTIC CELLS. THE 719 00:32:22,080 --> 00:32:23,120 VASE SHAPED STRUCTURE IN THE 720 00:32:23,120 --> 00:32:27,960 UPPER CENTER IS ABOUT 100 MIC 721 00:32:27,960 --> 00:32:31,720 MICRONS LONG. THAT IS A TESTMENT 722 00:32:31,720 --> 00:32:35,600 ON THE LEFT YOU ARE LOOKING AT A 723 00:32:35,600 --> 00:32:37,880 SMALL PIECE OF GREEN ALGA, THE 724 00:32:37,880 --> 00:32:39,200 THING BOTTOM CENTER IS ABOUT 725 00:32:39,200 --> 00:32:42,880 HALF A MILLIMETER ACROSS. IT HAS 726 00:32:42,880 --> 00:32:46,160 A CYST INSIDE SO CLEARLY 727 00:32:46,160 --> 00:32:47,160 EUKARYOTIC THOUGH WE CAN'T PIN 728 00:32:47,160 --> 00:32:48,480 IT TO A GROUP. SO WHAT WE ARE 729 00:32:48,480 --> 00:32:50,080 SEEING IS THE FOSSIL RECORD IS 730 00:32:50,080 --> 00:32:54,920 SHOWING US THAT YES, THERE IS 731 00:32:54,920 --> 00:32:55,760 EVIDENCE OF LIFE WELL BEFORE 732 00:32:55,760 --> 00:32:58,800 EARLIEST ANIMALS THAT WE SEE. 733 00:32:58,800 --> 00:33:03,240 THERE IS A MUCH MORE CONSPICUOUS 734 00:33:03,240 --> 00:33:07,480 EVIDENCE OF LIFE, CALLED 735 00:33:07,480 --> 00:33:09,160 STROMATOLITES. LOOK IN THE UPPER 736 00:33:09,160 --> 00:33:10,520 LEFT HAND PICTURE YOU SEE THE 737 00:33:10,520 --> 00:33:14,880 MIDDLE OF THE CLIFF LOZENGE 738 00:33:14,880 --> 00:33:17,320 BASED SHAPE STRUCTURES ABOUT 739 00:33:17,320 --> 00:33:18,600 FOUR TO FIVE METERS THICK. THOSE 740 00:33:18,600 --> 00:33:20,240 ARE MICROBIAL RREEFS. LOOK AT 741 00:33:20,240 --> 00:33:22,360 THE RIGHT YOU SEE SOME OF THESE 742 00:33:22,360 --> 00:33:24,680 TYPES OF STRUCTURES CLOSE UP, 743 00:33:24,680 --> 00:33:27,680 THERE ARE UPWARD DOMAIN LAMB 744 00:33:27,680 --> 00:33:30,760 NATIONS, AND OHIO LA MY NATION, 745 00:33:30,760 --> 00:33:32,640 YOU CAN SEE IN THE LOWER LEFT 746 00:33:32,640 --> 00:33:35,000 PLACE CALLED SHARK BAY WESTERN 747 00:33:35,000 --> 00:33:37,160 AUSTRALIA, THERE ARE PLACES 748 00:33:37,160 --> 00:33:39,040 TODAY WHERE THESE KINDS 749 00:33:39,040 --> 00:33:40,000 LAMINATED STRUCTURES FORM AND 750 00:33:40,000 --> 00:33:42,200 THEY ARE FORMED BY MICROBIAL 751 00:33:42,200 --> 00:33:44,960 COMMUNITIES. SO WE ARE USED TO 752 00:33:44,960 --> 00:33:47,840 THINKING OF RREEFS AS BEING 753 00:33:47,840 --> 00:33:49,440 STRUCTURES BUILT BY QUARRELS BUT 754 00:33:49,440 --> 00:33:52,480 MOST OF EARTH HISTORY RREEFS 755 00:33:52,480 --> 00:33:54,560 WERE BUILT BY MICROBIAL 756 00:33:54,560 --> 00:33:56,120 COMMUNITIES. THEN THERE IS 757 00:33:56,120 --> 00:33:59,320 CHEMICAL EVIDENCE FOR LIFE. 758 00:33:59,320 --> 00:34:01,280 THINGS LIKE DNA AND PROTEINS DO 759 00:34:01,280 --> 00:34:02,520 NOT PRESERVE WELL. THE OLDEST 760 00:34:02,520 --> 00:34:06,160 DNA WE KNOW OF IS ABOUT 2 761 00:34:06,160 --> 00:34:08,560 MILLION YEARS. BUT OTHER 762 00:34:08,560 --> 00:34:10,040 MOLECULES, PARTICULARLY LIPIDS 763 00:34:10,040 --> 00:34:11,600 CAN PRESERVE GEOLOGIC RECORD 764 00:34:11,600 --> 00:34:15,280 VERY WELL, FOR YEARS I USED TO 765 00:34:15,280 --> 00:34:16,600 TELL MY STUDENTS WHEN THEY DIE 766 00:34:16,600 --> 00:34:18,000 THE LASTING PART OF THEM 767 00:34:18,000 --> 00:34:21,080 AVAILABLE FOR THEIR DESCENDENTS 768 00:34:21,080 --> 00:34:22,320 TO CONTEMPLATE WOULD BE THEIR 769 00:34:22,320 --> 00:34:23,960 CHOLESTEROL, THAT IS NOT SO FAR 770 00:34:23,960 --> 00:34:28,120 OFF. SO VERY FEW EUKARYOTS 771 00:34:28,120 --> 00:34:30,240 PRODUCE VARIETY OF DIFFERENT 772 00:34:30,240 --> 00:34:33,000 STEROL, THEIR CARBON SKELETONS 773 00:34:33,000 --> 00:34:34,320 ARE PRESERVABLE IN THE RECORD 774 00:34:34,320 --> 00:34:38,000 AND THEY PROVIDE AN AUGMENTED 775 00:34:38,000 --> 00:34:41,000 VIEW OF BIOLOGICAL DIVERSITY IN 776 00:34:41,000 --> 00:34:42,960 THESE ROCKS. THE SAME THING IS 777 00:34:42,960 --> 00:34:46,680 TRUE OF THINGS LIKE BACTERIA, A 778 00:34:46,680 --> 00:34:50,320 VARIETY OF -- SO WE HAVE THIS 779 00:34:50,320 --> 00:34:51,960 MOLECULAR FOSSIL RECORD TO 780 00:34:51,960 --> 00:34:53,840 COMPLIMENT THAT OF MORPHOLOGY. 781 00:34:53,840 --> 00:34:56,040 THEN MICROBES CAN ACTUALLY 782 00:34:56,040 --> 00:34:57,920 INFLUENCE CHEMICAL STRUCTURE OF 783 00:34:57,920 --> 00:34:58,920 SEDIMENTS BECAUSE OF THEIR 784 00:34:58,920 --> 00:35:02,840 METABOLISM. IF YOU GO DOWN TO 785 00:35:02,840 --> 00:35:06,720 BAHAMAS AND LOOK AT THE RATIO OF 786 00:35:06,720 --> 00:35:13,880 THE TWO -- THE TWO STABLE CARBON 787 00:35:13,880 --> 00:35:16,840 ISOTOPES, C 13 AND C 12 IN THE 788 00:35:16,840 --> 00:35:17,720 CARBON ATTACHED. 789 00:35:17,720 --> 00:35:19,400 S YOU WILL FIND THAT RATIO ON 790 00:35:19,400 --> 00:35:21,960 THE ARBITRARY SCALE IS 791 00:35:21,960 --> 00:35:22,800 ESTABLISHED TO DISCUSS THESE 792 00:35:22,800 --> 00:35:24,640 THINGS IS ZERO. THAT IS VERY 793 00:35:24,640 --> 00:35:25,640 MUCH LIKE A STANDARD THAT IS 794 00:35:25,640 --> 00:35:28,560 JUICED. LOOK AT ORGANIC -- 795 00:35:28,560 --> 00:35:30,280 USED. LOOKING AT ORGANIC MATTER 796 00:35:30,280 --> 00:35:31,280 IN THE SIAMESED. 797 00:35:31,280 --> 00:35:35,600 S IT IS DEPLETED IN 13C BY 25 798 00:35:35,600 --> 00:35:37,360 PARTS PER THOUSAND. THAT 799 00:35:37,360 --> 00:35:39,520 DEPLETION REFLECTS THE FACT THAT 800 00:35:39,520 --> 00:35:42,760 DURING PHOTOSYNTHESIS CARBON 801 00:35:42,760 --> 00:35:46,520 DIOXIDE WITH THE LIGHTER STABLE 802 00:35:46,520 --> 00:35:48,520 ISOTOPE C 12 IS PREFERENTIALLY 803 00:35:48,520 --> 00:35:50,080 INCORPORATED INTO ORGANIC 804 00:35:50,080 --> 00:35:54,640 MOLECULES. SO THAT GIVES US A 805 00:35:54,640 --> 00:35:55,800 CHEMICAL MARK E FOR A BIOLOGICAL 806 00:35:55,800 --> 00:35:57,680 CARBON CYCLE. AND THAT IS WHAT 807 00:35:57,680 --> 00:36:00,040 WE SEE IN ROCKS THAT ARE 800 808 00:36:00,040 --> 00:36:01,640 MILLION YEARS OLD AND AS THIS 809 00:36:01,640 --> 00:36:03,720 DIAGRAM INDICATES YOU SEE THAT 810 00:36:03,720 --> 00:36:08,480 IN MUCH OLDER ROCKS AS WELL. 811 00:36:08,480 --> 00:36:10,080 THE POINT IS THAT IN FACT WHEN 812 00:36:10,080 --> 00:36:13,920 YOU LOOK AT THESE ROCKS MORE 813 00:36:13,920 --> 00:36:14,880 ANCIENT THAN ANYTHING THAT 814 00:36:14,880 --> 00:36:16,600 CONTAINS ANIMALS, THE FINGER 815 00:36:16,600 --> 00:36:18,800 PRINTS OF BIOLOGY ARE 816 00:36:18,800 --> 00:36:19,960 EVERYWHERE. WE CAN INTERPRET 817 00:36:19,960 --> 00:36:22,200 THOSE BY LOOKING AT MODERN 818 00:36:22,200 --> 00:36:25,280 PLACES LIKE THIS PICTURE YOU SEE 819 00:36:25,280 --> 00:36:27,680 IN THE TURKS AND KAKOS ISLANDS 820 00:36:27,680 --> 00:36:29,600 WHERE I HAVE WORKED RECENTLY, WE 821 00:36:29,600 --> 00:36:31,560 CAN LOOK AT MODERN MICROBIAL 822 00:36:31,560 --> 00:36:34,480 SYSTEMS AND UNDERSTAND HOW WILL 823 00:36:34,480 --> 00:36:35,840 LIVING MATS ARE BASICALLY 824 00:36:35,840 --> 00:36:37,680 TRANSFORMED INTO THIS 825 00:36:37,680 --> 00:36:38,360 GEOLOGICALLY PRESERVABLE 826 00:36:38,360 --> 00:36:46,040 INFORMATION. WE KNOW THERE IS A 827 00:36:46,040 --> 00:36:49,280 ANIMAL GEE LOGICAL RECORD OF 828 00:36:49,280 --> 00:36:51,880 MICROBES -- GEOLOGICAL RECORD OF 829 00:36:51,880 --> 00:36:54,200 MICROBES. LET'S DOUBLE THE AGE 830 00:36:54,200 --> 00:36:56,840 FIRST OF ALL ALL. YOU ARE B LOT 831 00:36:56,840 --> 00:36:59,800 BEAUTIFUL EXPOSED ROCKS NORTHERN 832 00:36:59,800 --> 00:37:01,000 SIBERIA, ABOUT 1,500,000,000 833 00:37:01,000 --> 00:37:04,000 YEARS OLD, AS YOU SEE OBJECT 834 00:37:04,000 --> 00:37:06,400 RIGHT THEY HAVE CYANO BACTERIA 835 00:37:06,400 --> 00:37:09,360 AN EUKARYOTIC CELLS, TEN MICRON 836 00:37:09,360 --> 00:37:13,080 SCALES. LOOK AT CARBON NITROGEN 837 00:37:13,080 --> 00:37:16,200 AND SULFUR ISOTOPES THEN THEIR 838 00:37:16,200 --> 00:37:18,520 ISOTOPIC SYSTEMATIC TELLS THEY 839 00:37:18,520 --> 00:37:21,960 WERE BIOLOGIC CARBON SULFUR AND 840 00:37:21,960 --> 00:37:25,800 NITROGEN CYCLES THEN. THERE ARE 841 00:37:25,800 --> 00:37:27,080 MOLECULAR BIOMARKERS IN THESE 842 00:37:27,080 --> 00:37:29,640 ROCKS. AND I LOVE THE PICTURE ON 843 00:37:29,640 --> 00:37:33,640 THE LOWER LEFT, BECAUSE FIRST OF 844 00:37:33,640 --> 00:37:35,560 ALL MY RUSSIAN COLLEAGUE 845 00:37:35,560 --> 00:37:37,800 STANDING THERE IS EXACTLY TWO 846 00:37:37,800 --> 00:37:39,800 METERS TALLER THAN HIS HAT SO A 847 00:37:39,800 --> 00:37:41,080 VERY CONVENIENT MARKER THAT YOU 848 00:37:41,080 --> 00:37:43,360 MIGHT SAY I SEE WHAT YOU POINT 849 00:37:43,360 --> 00:37:45,120 OUT HERE, RIGHT IN THE CENTER 850 00:37:45,120 --> 00:37:47,160 THERE IS SORT OF ROUND 851 00:37:47,160 --> 00:37:48,800 STRUCTURE, I BET THAT SOMEONE OF 852 00:37:48,800 --> 00:37:50,240 THE MICROBIAL RREEFS. IT IS. 853 00:37:50,240 --> 00:37:54,760 IT IS MICROBE YAHT REEF, MAYBE 854 00:37:54,760 --> 00:37:58,080 THE SIDE -- MICROBIAL REEF, 855 00:37:58,080 --> 00:37:58,840 MAYBE SIZE OF A BIN SOMETHING 856 00:37:58,840 --> 00:38:00,640 LIKE THAT. SO IF YOU NOTICE THE 857 00:38:00,640 --> 00:38:02,560 POINTS, TURNS OUTS TO BE 15 858 00:38:02,560 --> 00:38:03,960 POINT QUESTION BECAUSE IF YOU 859 00:38:03,960 --> 00:38:06,280 LOOK AT WHERE MY FRIEND MISHA IS 860 00:38:06,280 --> 00:38:07,560 STANDING, IT IS A CURVED SURFACE 861 00:38:07,560 --> 00:38:10,720 AND THAT IS PROBABLY A -- IT IS 862 00:38:10,720 --> 00:38:13,720 A MICROBIAL REEF AS LARGE AS A 863 00:38:13,720 --> 00:38:18,560 LARGE LECTURE HALL. IF YOU LOOK 864 00:38:18,560 --> 00:38:22,080 AT BEHIND HIM THAT IS ASTRO MAT 865 00:38:22,080 --> 00:38:25,080 LYTIC RE,F THAT COVERS THE CLIFF 866 00:38:25,080 --> 00:38:27,080 WALL, THAT IS A REEF WITH THE 867 00:38:27,080 --> 00:38:28,320 DIMENSIONS MAYBE THE SIZE OF ONE 868 00:38:28,320 --> 00:38:29,240 OF YOUR RESEARCH WHICH 869 00:38:29,240 --> 00:38:35,560 WOULDIWHIBUILDINGS.SHOWING MICRA 870 00:38:35,560 --> 00:38:38,600 LONG HISTORY THAT LONG 871 00:38:38,600 --> 00:38:40,480 ANTI-DATES ANYTHING BUILT BY 872 00:38:40,480 --> 00:38:42,000 CORALS. SO DOUBLE THE AGE 873 00:38:42,000 --> 00:38:43,480 AGAIN, GO BACK TO ROCKS IN 874 00:38:43,480 --> 00:38:45,720 WESTERN AUSTRALIA, NEARLY 3 1/2 875 00:38:45,720 --> 00:38:46,640 BILLION YEARS OLD AND ARE SOME 876 00:38:46,640 --> 00:38:48,920 OF THE OLDEST ROCKS WELL ENOUGH 877 00:38:48,920 --> 00:38:51,200 PRESERVED TO ASK QUESTIONS ABOUT 878 00:38:51,200 --> 00:38:52,760 BIOLOGY. WHAT DO WE FIND WHEN WE 879 00:38:52,760 --> 00:38:55,000 LOOK AT THOSE? TURNS OUT THEY 880 00:38:55,000 --> 00:38:58,920 ARE STROMATLO LIGHTS IN THEM SO 881 00:38:58,920 --> 00:39:03,040 MICROBIAL COMMUNITIES COVERING 882 00:39:03,040 --> 00:39:06,360 SURFACES WITHIN ANCIENT ZONE. WE 883 00:39:06,360 --> 00:39:09,760 DON'T FIND MOLECULAR FOSSILS 884 00:39:09,760 --> 00:39:11,360 DISCERNIBLE BUT WE STILL SEE 885 00:39:11,360 --> 00:39:14,440 THIS ISOTOPIC SEPARATION BETWEEN 886 00:39:14,440 --> 00:39:15,720 CARBONATE AND ORGANIC CARBON 887 00:39:15,720 --> 00:39:16,960 THAT TELL US THERE WAS A 888 00:39:16,960 --> 00:39:19,200 BIOLOGICAL CARBON CYCLE. WE CAN 889 00:39:19,200 --> 00:39:20,760 ALSO LOOK AT SULFUR ISOTOPES AND 890 00:39:20,760 --> 00:39:22,240 COME TO THE SAME CONCLUSION 891 00:39:22,240 --> 00:39:25,840 ABOUT A BIOLOGICAL SULFUR CYCLE 892 00:39:25,840 --> 00:39:27,800 THINGS THAT HAVE BEEN CALLED 893 00:39:27,800 --> 00:39:28,840 FOSSILS HAVE BEEN DESCRIBED SO 894 00:39:28,840 --> 00:39:31,600 IF YOU LOOK AT THIS IMAGE ON THE 895 00:39:31,600 --> 00:39:33,840 LEFT THOSE ARE TEN MICRON 896 00:39:33,840 --> 00:39:36,320 ORGANIC SMEARS THAT HAVE BEEN 897 00:39:36,320 --> 00:39:38,440 INTERPRETED AS FOSSILS. 898 00:39:38,440 --> 00:39:41,200 BUT IF YOU LOOK AT THE BLACK 899 00:39:41,200 --> 00:39:43,680 SPHERES YOU SEE IN THE UPPER 900 00:39:43,680 --> 00:39:45,200 RIGHT, THOSE ARE NOT FOSSILS 901 00:39:45,200 --> 00:39:47,880 THOSE ARE PRODUCTS OF ORGANIC 902 00:39:47,880 --> 00:39:50,720 MATTER REMOBILIZATION BY HYDRO 903 00:39:50,720 --> 00:39:52,000 THERMAL FLUID FLOW AND TURNS OUT 904 00:39:52,000 --> 00:39:54,080 THAT ALL OF THESE ROCKS THREE 905 00:39:54,080 --> 00:39:55,880 AND A HALF BILLION YEARS OLD 906 00:39:55,880 --> 00:39:57,760 HAVE BEEN SUBJECT TO HYDRO 907 00:39:57,760 --> 00:39:59,400 THERMAL FLUID FLOW SO WE HAVE TO 908 00:39:59,400 --> 00:40:00,680 BE AGNOSTIC ABOUT FOSSILS PER 909 00:40:00,680 --> 00:40:07,920 SE. I THINK THE EVIDENCE IS 910 00:40:07,920 --> 00:40:09,320 STRONG THAT SUGGEST THAT LIFE 911 00:40:09,320 --> 00:40:11,800 HAS BEEN A PART OF THE EARTH 912 00:40:11,800 --> 00:40:14,000 SYSTEM SINCE VERY EARLY IN OUR 913 00:40:14,000 --> 00:40:16,760 PLANET HISTORY. THAT IS THE 914 00:40:16,760 --> 00:40:18,400 FIRST TIME WE HAVE ROCKS THAT 915 00:40:18,400 --> 00:40:20,400 CAN BE INTERROGATED FOR 916 00:40:20,400 --> 00:40:22,480 QUESTIONS OF BIOLOGY, LIFE IS 917 00:40:22,480 --> 00:40:24,120 ALREADY THERE. THERE IS 918 00:40:24,120 --> 00:40:25,360 UNCERTAINTIES ABOUT WHAT THE 919 00:40:25,360 --> 00:40:26,720 NATURE AND DIVERSITY OF THAT 920 00:40:26,720 --> 00:40:31,280 LIFE WAS. BUT ONE THING IS CLEAR 921 00:40:31,280 --> 00:40:32,800 FROM GEOCHEMISTRY, THAT THIS WAS 922 00:40:32,800 --> 00:40:38,720 A WORLD WITHOUT OXYGEN. SO WHAT 923 00:40:38,720 --> 00:40:42,320 ARE THE CONSEQUENCES OF HAVING A 924 00:40:42,320 --> 00:40:43,920 WORLD WITHOUT OXYGEN? IF YOU ARE 925 00:40:43,920 --> 00:40:45,600 INTERESTING IN AUTOTROPHY, THERE 926 00:40:45,600 --> 00:40:48,560 ARE MORE ELECTRON DONORS AND FEW 927 00:40:48,560 --> 00:40:52,360 THAT ELECTRON ACCEPTORS. AS WE 928 00:40:52,360 --> 00:40:55,320 SEE MORE IN A SECOND, IN THIS 929 00:40:55,320 --> 00:40:56,800 WORLD THERE WOULD HAVE BEEN VERY 930 00:40:56,800 --> 00:41:00,560 LIMITED PHOSPHORUS AVAILABLE FOR 931 00:41:00,560 --> 00:41:02,160 PRIMARY PRODUCTION BECAUSE FOR 932 00:41:02,160 --> 00:41:03,920 ONE THING PHOSPHATE WOULD BE 933 00:41:03,920 --> 00:41:06,880 OBSERVED ABSORBED ON IRON 934 00:41:06,880 --> 00:41:10,480 MINERALS AND BE REMOVED FROM 935 00:41:10,480 --> 00:41:12,480 BIOLOGICAL CONSIDERATIONS. THERE 936 00:41:12,480 --> 00:41:16,400 WOULD HAVE BEEN SOME NITROGEN 937 00:41:16,400 --> 00:41:18,240 NITRATE MADE BY ABIOTIC NIGH 938 00:41:18,240 --> 00:41:21,480 THROW GENERAL FIXATION, 939 00:41:21,480 --> 00:41:23,160 LIGHTNING PASSING THROUGH THE 940 00:41:23,160 --> 00:41:24,400 ATMOSPHERE PRODUCE AT LEAST 941 00:41:24,400 --> 00:41:25,560 COUPLE OF PERCENT OF THE 942 00:41:25,560 --> 00:41:26,640 NITROGEN FIXED BY MICROBES 943 00:41:26,640 --> 00:41:31,600 TODAY. IMPORTANTLY FOR THINKING 944 00:41:31,600 --> 00:41:34,200 EVOLUTION, A LOT OF TRACE METALS 945 00:41:34,200 --> 00:41:36,760 ARE REDOX SENSITIVE AND SO IN A 946 00:41:36,760 --> 00:41:40,400 WORLD WITHOUT OXYGEN YOU HAVE 947 00:41:40,400 --> 00:41:43,680 MORE IRON COBALT AND MANGANESE 948 00:41:43,680 --> 00:41:47,080 BUT THINGS LIKE COPPER ALUMINUM 949 00:41:47,080 --> 00:41:50,320 AN ZINC WOULD BE MUCH LESS 950 00:41:50,320 --> 00:41:51,440 ABUNDANCE THAN THEY ARE TODAY. 951 00:41:51,440 --> 00:41:53,760 ALL THAT CHANGES ABOUT 952 00:41:53,760 --> 00:41:55,560 2.4 BILLION YEARS AGO, THE GREAT 953 00:41:55,560 --> 00:41:57,600 OXYGENATION EVENT. AND SEVERAL 954 00:41:57,600 --> 00:41:59,200 LINES OF EVIDENCE; I WON'T TALK 955 00:41:59,200 --> 00:42:00,800 THE TIME TO RUN THROUGH THEM, 956 00:42:00,800 --> 00:42:03,920 BUT BE HAPPY TO TALK ABOUT THEM 957 00:42:03,920 --> 00:42:05,240 TELL US THIS IS WHEN WE FIRST 958 00:42:05,240 --> 00:42:10,200 STARTED TO GET A PERMANENT 959 00:42:10,200 --> 00:42:12,160 QUANTITY OF OXYGEN GAS IN THE 960 00:42:12,160 --> 00:42:17,400 ATMOSPHERE AND SURFACE OCEAN. 961 00:42:17,400 --> 00:42:19,080 ONLY ONE SOURCE OF OXYGEN 962 00:42:19,080 --> 00:42:21,920 POSSIBLE TO FUEL THAT AND THAT 963 00:42:21,920 --> 00:42:28,040 IS CYANO BACTERIA. FOR THE FIRST 964 00:42:28,040 --> 00:42:30,320 BILLION YEARS OF LIFE EARTH WAS 965 00:42:30,320 --> 00:42:33,640 LARGELY A WATER PLANET, THAT IS 966 00:42:33,640 --> 00:42:35,680 WHILE THERE WAS SOME CONTINENTAL 967 00:42:35,680 --> 00:42:38,080 CROSS VERY LITTLE WAS EMERGENT. 968 00:42:38,080 --> 00:42:40,640 IF YOU HAD TAKEN A SATELLITE 969 00:42:40,640 --> 00:42:42,280 PHOTO OF THE WORLD 3 1/2 BILLION 970 00:42:42,280 --> 00:42:44,080 YEARS AGO, YOU WOULD HAVE SEEN 971 00:42:44,080 --> 00:42:46,080 VOLCANOS STICKING OUT, MAYBE 972 00:42:46,080 --> 00:42:49,120 SOME MICROBE COTTONE,LLE MASSES 973 00:42:49,120 --> 00:42:50,400 BUT LARGELY YOU WOULD HAVE SEEN 974 00:42:50,400 --> 00:42:51,840 WATER. THAT KIND OF WORLD THERE 975 00:42:51,840 --> 00:42:53,360 IS LIMITED WEATHERING AND 976 00:42:53,360 --> 00:42:55,360 EROSION SO THERE IS LESS 977 00:42:55,360 --> 00:42:58,400 PHOSPHORUS COMING TO THE SYSTEM. 978 00:42:58,400 --> 00:43:02,920 AS I ALREADY MENTIONED, THERE 979 00:43:02,920 --> 00:43:05,400 WERE A LOT OF IRON IN SEA WATER, 980 00:43:05,400 --> 00:43:10,760 THAT RESULTS IN PRECIPITATION OF 981 00:43:10,760 --> 00:43:13,360 PHOSPHORUS AS PHOSPHATE BY 982 00:43:13,360 --> 00:43:14,800 ITSELF, PHOSPHATE MINERALS 983 00:43:14,800 --> 00:43:16,480 BECAUSE THEY ARE LIMITED OXYGEN, 984 00:43:16,480 --> 00:43:18,280 THERE WOULD HAVE BEEN LIMITED 985 00:43:18,280 --> 00:43:19,080 ORGANIC REMAIN RAILIZATION SO 986 00:43:19,080 --> 00:43:21,640 THERE WASN'T MUCH OF A 987 00:43:21,640 --> 00:43:24,960 REMINERALIZATION OF NUTRIENTS. 988 00:43:24,960 --> 00:43:27,400 IN THIS WORLD IT IS VERY LIKELY 989 00:43:27,400 --> 00:43:30,680 THAT MUCH OF THE PHOTOSYNTHESIS 990 00:43:30,680 --> 00:43:33,440 WAS DONE BY THESE PAN OXIC FLOW 991 00:43:33,440 --> 00:43:35,680 SYNTHETIC BACTERIA, PARTICULARLY 992 00:43:35,680 --> 00:43:41,520 ONES THAT AREN'T ABLE TO USE 993 00:43:41,520 --> 00:43:44,040 FERRIS IRON. WHY DOES THAT 994 00:43:44,040 --> 00:43:45,240 CHANGE 2.4 BILLION YEARS AGO? 995 00:43:45,240 --> 00:43:46,440 THE MAIN THING THAT SEEMS TO 996 00:43:46,440 --> 00:43:47,840 HAPPEN IS THE CONTINENTS HAVE 997 00:43:47,840 --> 00:43:49,840 MERGED. THIS IS A RESULT OF 998 00:43:49,840 --> 00:43:51,280 COOLING MANTEL, WE TALKED ABOUT 999 00:43:51,280 --> 00:43:53,840 IN MORE DETAIL, IF YOU ARE 1000 00:43:53,840 --> 00:43:56,680 INTERESTED IN IT BUT BECAUSE OF 1001 00:43:56,680 --> 00:43:59,280 THAT CONTINENTS EMERGE CHANGES 1002 00:43:59,280 --> 00:44:02,880 THE DYNAMICS OF THE PHOSPHORUS 1003 00:44:02,880 --> 00:44:06,040 CYCLE IN A WAY THAT WOULD FAVOR 1004 00:44:06,040 --> 00:44:09,760 CYANO BACTERIA. HOW MUCH OXYGEN 1005 00:44:09,760 --> 00:44:12,320 DO WE GET AT THAT POINT? ANSWER 1006 00:44:12,320 --> 00:44:13,720 IS PROBABLY NOT MUCH. THERE IS 1007 00:44:13,720 --> 00:44:15,200 DEBATE ON THIS BUT SOMEWHERE ON 1008 00:44:15,200 --> 00:44:17,720 THE ORDER OF 1 TO A FEW PERCENT 1009 00:44:17,720 --> 00:44:19,440 OF PRESENT DAY OXYGEN LEVELS 1010 00:44:19,440 --> 00:44:22,040 WERE IN THE ATMOSPHERE. MOST OF 1011 00:44:22,040 --> 00:44:26,040 THE OCEANS REMAIN AN OXIC THERE 1012 00:44:26,040 --> 00:44:28,200 ARE VARIETY OF DIFFERENT 1013 00:44:28,200 --> 00:44:30,360 GEOCHEMICAL INDICATORS OF THIS 1014 00:44:30,360 --> 00:44:36,120 ABUNDANCE AS ISOTOPES OF REDOX 1015 00:44:36,120 --> 00:44:38,000 SENSITIVE ELEMENTS. SO STARTS 1016 00:44:38,000 --> 00:44:41,760 MILLION DOLLAR AGE IF YOU WILL. 1017 00:44:41,760 --> 00:44:43,480 ONE CONSEQUENCE OF MODEST AMOUNT 1018 00:44:43,480 --> 00:44:45,480 OF OXYGEN TO ATMOSPHERE SURFACE 1019 00:44:45,480 --> 00:44:49,920 OCEAN IS EXPAND OXIDANT POOLS 1020 00:44:49,920 --> 00:44:54,040 FOR RESPIRATION AND 1021 00:44:54,040 --> 00:44:55,040 CHEMOSYNTHESIS, YOU INCREASE 1022 00:44:55,040 --> 00:44:56,680 ORGANIC MATTER WHICH RETURN MORE 1023 00:44:56,680 --> 00:45:02,040 NUTRIENTS TO THE WATER COLUMN 1024 00:45:02,040 --> 00:45:08,920 FOR AND CYANO BACTERIA ARE 1025 00:45:08,920 --> 00:45:10,400 ECOSYSTEM ENGINEERS AS THEY ADD 1026 00:45:10,400 --> 00:45:13,160 OXIC TO THE ZONE THEY SCRUB IT 1027 00:45:13,160 --> 00:45:15,800 CLEAN OF ALTERNATIVE ELECTRON 1028 00:45:15,800 --> 00:45:21,280 DONORS AND SO BASICALLY BECOMES 1029 00:45:21,280 --> 00:45:23,520 THE CYANO BACTERIA WORLD. THERE 1030 00:45:23,520 --> 00:45:26,680 IS A NEW TYPE OF LIFE, THE 1031 00:45:26,680 --> 00:45:28,160 EUKARYOTIC CELL. LAST COMMON 1032 00:45:28,160 --> 00:45:31,080 ANCESTOR OF LIVING EUKARYOTS HAD 1033 00:45:31,080 --> 00:45:35,000 MITOCHONDRIA THAT WERE CAPABLE 1034 00:45:35,000 --> 00:45:37,920 OF RESPIRATION AND THAT BECOMES 1035 00:45:37,920 --> 00:45:39,920 POSSIBLE AS OXYGEN STARTS TO BE 1036 00:45:39,920 --> 00:45:40,400 PERSISTENT PART OF THE 1037 00:45:40,400 --> 00:45:48,720 ENVIRONMENT. THIS SHOWS US 1038 00:45:48,720 --> 00:45:50,360 EUKARYOTS BACK TO 700 MILLION 1039 00:45:50,360 --> 00:45:52,200 YEARS AGO OR SO. BY A BILLION 1040 00:45:52,200 --> 00:45:55,200 YEARS OR SO WE HAVE RED AND 1041 00:45:55,200 --> 00:45:57,800 GREEN ALGAE, TWO LARGER ONES ON 1042 00:45:57,800 --> 00:46:00,520 YOUR LEFT. WE HAVE OTHER SIMPLE 1043 00:46:00,520 --> 00:46:02,200 MULTI-CELLULAR EUKARYOTS THAT GO 1044 00:46:02,200 --> 00:46:03,920 BACK TO ALMOST AS OLE AS 1045 00:46:03,920 --> 00:46:09,800 EUKARYOTS AS A WHOLE. WITH THIS 1046 00:46:09,800 --> 00:46:12,440 OXYGEN ECOSYSTEMS EXPAND THOUGH 1047 00:46:12,440 --> 00:46:17,320 CONTROL REMAINS FIRMLY UNDER 1048 00:46:17,320 --> 00:46:18,760 BACTERIAL CONTROL. IN FACT 1049 00:46:18,760 --> 00:46:21,000 DESPITE THE FACT THAT WE HAVE 1050 00:46:21,000 --> 00:46:23,880 GREEN AND RED ALGAE MORE THAN A 1051 00:46:23,880 --> 00:46:26,640 BILLION YEARS AGO, MOLECULAR 1052 00:46:26,640 --> 00:46:29,800 FOSSILS TELL US THAT EUKARYOTS 1053 00:46:29,800 --> 00:46:32,920 ONLY BECAME MAJOR PRIMARY 1054 00:46:32,920 --> 00:46:35,920 PRODUCERS AROUND 6 HUNT MILLION 1055 00:46:35,920 --> 00:46:37,640 YEARS AGO. BOTH FOSSILS AN 1056 00:46:37,640 --> 00:46:39,480 MOLECULAR MARKERS INDICATE THAT. 1057 00:46:39,480 --> 00:46:44,320 WE FIRST START SEEING ABUNDANT 1058 00:46:44,320 --> 00:46:49,280 GREEN STERINES ONLY 600 TO 580 1059 00:46:49,280 --> 00:46:50,360 BILLION YEARS AGO. SO SOMETHING 1060 00:46:50,360 --> 00:46:52,040 IS CHANGING. SOMETHING IS 1061 00:46:52,040 --> 00:46:53,360 CHANGING. AND WHAT WE THINK IS 1062 00:46:53,360 --> 00:46:55,160 CHANGING IS THE NUTRIENTS STATUS 1063 00:46:55,160 --> 00:46:57,960 OF THE WORLD. BECAUSE IF YOU 1064 00:46:57,960 --> 00:47:00,720 LOOK AT OCEAN TODAY WHERE 1065 00:47:00,720 --> 00:47:05,960 NUTRIENT LEVELS ARE LOW, PRIMARY 1066 00:47:05,960 --> 00:47:08,240 PRODUCTION IS DOMINATED BY CYANO 1067 00:47:08,240 --> 00:47:11,120 BACTERIA. THE CENTRAL DRIVER OF 1068 00:47:11,120 --> 00:47:11,880 OCEAN SPRINGS BUT MORE NUTRIENTS 1069 00:47:11,880 --> 00:47:16,880 YOU START BRINGING IN LARGER 1070 00:47:16,880 --> 00:47:18,120 EUKARYOTIC CELLS, MORE GREEN 1071 00:47:18,120 --> 00:47:20,760 ALGAE, IF YOU ADD A LOT OF 1072 00:47:20,760 --> 00:47:23,120 NUTRIENTS YOU GET DIATOMS, 1073 00:47:23,120 --> 00:47:25,640 IMPORTANT PRIMARY PRODUCERS 1074 00:47:25,640 --> 00:47:26,640 TODAY. ALWAYS INTERESTING BUT 1075 00:47:26,640 --> 00:47:28,640 THAT WHAT WE SEE IN SPACE 1076 00:47:28,640 --> 00:47:30,680 MIRRORS WHAT WE SEE IN TIME. 1077 00:47:30,680 --> 00:47:32,600 THAT WE HAVE CYANO BACTERIA ONLY 1078 00:47:32,600 --> 00:47:36,480 NEAR THE END OF THE DO WE SEE 1079 00:47:36,480 --> 00:47:39,800 GREEN ALGAE AND ONLY THE LAST 1080 00:47:39,800 --> 00:47:43,560 150 MILLION YEARS AGO DO WE SEE 1081 00:47:43,560 --> 00:47:46,400 DIATOPS: WHAT CHANGES? 600 1082 00:47:46,400 --> 00:47:49,600 MILLION YEARS AGO? ONE THING WE 1083 00:47:49,600 --> 00:47:53,320 NOTICED THAT IS THE WHOLE RECORD 1084 00:47:53,320 --> 00:47:56,080 OF PHOSPHORUS CHANGES. THIS IS 1085 00:47:56,080 --> 00:47:58,360 THERE IS ECONOMIC CONSEQUENCE OF 1086 00:47:58,360 --> 00:48:00,640 THIS BECAUSE THE PHOSPHATE USED 1087 00:48:00,640 --> 00:48:03,040 IN FERTILIZER WHICH IS A WASTING 1088 00:48:03,040 --> 00:48:05,760 RESOURCE AS IT TURNS OUT, AN OLD 1089 00:48:05,760 --> 00:48:07,880 STORY, IS ALMOST EXCLUSIVELY 1090 00:48:07,880 --> 00:48:11,240 FOUND IN ROCKS THAT ARE 600 1091 00:48:11,240 --> 00:48:14,000 MILLION YEARS OLD AND YOUNGER. 1092 00:48:14,000 --> 00:48:16,240 THERE IS ONE DEPOSIT IN CHINA 1093 00:48:16,240 --> 00:48:18,920 WITH MORE SEDIMENTARY PHOSPHATE 1094 00:48:18,920 --> 00:48:20,080 THAN THE ENTIRE GEOLOGIC RECORD 1095 00:48:20,080 --> 00:48:21,480 BEFORE THAT TIME. THIS IS A 1096 00:48:21,480 --> 00:48:26,920 TIME OF MAJOR MOUNTAIN BUILDING. 1097 00:48:26,920 --> 00:48:29,160 I THINK PROBABLY FOR THE FIRST 1098 00:48:29,160 --> 00:48:30,080 TIME THE MANTEL HAS COOLED 1099 00:48:30,080 --> 00:48:33,960 ENOUGH THAT WE GET HIM LAYIAN 1100 00:48:33,960 --> 00:48:35,560 STYLE MOUNTAINS THAT INCREASES 1101 00:48:35,560 --> 00:48:36,960 THE PHOSPHATE COMING INTO THE 1102 00:48:36,960 --> 00:48:41,240 OCEANS, THAT INCREASES OXYGEN 1103 00:48:41,240 --> 00:48:47,080 PRODUCTION, THAT INCREASES IF 1104 00:48:47,080 --> 00:48:49,960 YOU WILL THE REMINERALIZATION OF 1105 00:48:49,960 --> 00:48:53,200 ORGANIC MATTER SO WE STRENGTHEN 1106 00:48:53,200 --> 00:48:56,000 THIS UPWELLING WHICH TODAY IS 1107 00:48:56,000 --> 00:48:57,520 RESPONSIBLE FOR MOST PHOSPHORUS 1108 00:48:57,520 --> 00:49:02,320 CONSUMED BY LACTIN IN THE OCEAN 1109 00:49:02,320 --> 00:49:04,120 SO WE THINK THERE IS A TECTONIC 1110 00:49:04,120 --> 00:49:05,320 EVENT WHICH WILL CHANGE THE 1111 00:49:05,320 --> 00:49:09,800 NUTRIENT DYNAMICS OF THE WORLD 1112 00:49:09,800 --> 00:49:13,920 AND THAT HAS TWO CONSEQUENCES. 1113 00:49:13,920 --> 00:49:15,360 FIRST INDEPENDENT THIS EVIDENCE 1114 00:49:15,360 --> 00:49:16,240 THERE'S LOTS OF EVIDENCE THAT 1115 00:49:16,240 --> 00:49:19,600 TELL US OXYGEN IS GOING UP AND 1116 00:49:19,600 --> 00:49:20,960 STARTING ON THE ROAD TO THE 1117 00:49:20,960 --> 00:49:22,320 PRESENT DAY AMOUNTS THAT WE SEE 1118 00:49:22,320 --> 00:49:27,680 TODAY. ALSO AT THE SAME TIME WE 1119 00:49:27,680 --> 00:49:32,120 SEE OUR FIRST RECORD OF 1120 00:49:32,120 --> 00:49:35,120 MICROSCOPIC ANIMALS. IT IS 1121 00:49:35,120 --> 00:49:38,160 LIKELY THERE IS A CAUSAL BRIDGE 1122 00:49:38,160 --> 00:49:41,960 THAT RUNS FROM EARTH TECTONIC 1123 00:49:41,960 --> 00:49:45,080 HISTORY TO CHANGES IN NUTRIENT 1124 00:49:45,080 --> 00:49:47,280 DYNAMICS THAT CHANGES IN FOOD 1125 00:49:47,280 --> 00:49:49,600 AND OXYGEN AVAILABILITY. AND 1126 00:49:49,600 --> 00:49:51,120 ULTIMATELY RESULTS IN ANIMAL 1127 00:49:51,120 --> 00:49:55,880 DIVERSIFICATION. LET ME FINISH 1128 00:49:55,880 --> 00:50:00,480 UP THEN. BEGINNING 600 TO 550 1129 00:50:00,480 --> 00:50:01,880 MILLION YEARS AGO THIS NEW WORLD 1130 00:50:01,880 --> 00:50:03,680 STARTS TO TAKE SHAPE. A WORLD 1131 00:50:03,680 --> 00:50:08,640 WITH ANIMALS AND EVENTUALLY 1132 00:50:08,640 --> 00:50:10,120 PLANTS. FROM THE STANDPOINT OF 1133 00:50:10,120 --> 00:50:15,280 BACTERIA, THIS IS SIMPLY GIVING 1134 00:50:15,280 --> 00:50:18,360 THEM NEW TO CARBON, NOT ONLY 1135 00:50:18,360 --> 00:50:19,960 ANIMALS ARE INNER RELATED WITH 1136 00:50:19,960 --> 00:50:21,360 HUNDREDS OF BACTERIA BUT PLANTS 1137 00:50:21,360 --> 00:50:23,080 ARE AS WELL. WE ARE JUST 1138 00:50:23,080 --> 00:50:25,760 LEARNING THE PLANT MICROBIOME 1139 00:50:25,760 --> 00:50:27,440 BUT IT IS EXTENSIVE AND THERE 1140 00:50:27,440 --> 00:50:30,880 IS'S INTIMATE PHYSICAL LOGICAL 1141 00:50:30,880 --> 00:50:32,480 INTERACTIONS. TO SUMMARIZE THEN, 1142 00:50:32,480 --> 00:50:35,840 MICROBES PROVIDE THE PUNNED 1143 00:50:35,840 --> 00:50:38,640 MENTAL ECOLOGIC CIRCUITRY OF 1144 00:50:38,640 --> 00:50:41,320 LIFE ON EFFORT GEOLOGIC RECORDS 1145 00:50:41,320 --> 00:50:42,640 OF LIFE IS LONG, ALMOST AS LONG 1146 00:50:42,640 --> 00:50:44,760 AS THE RECORDS OF THE PLANET 1147 00:50:44,760 --> 00:50:45,920 ITSELF AND IT IS MOSTLY 1148 00:50:45,920 --> 00:50:48,640 MICROBIAL. COMPLEX 1149 00:50:48,640 --> 00:50:50,320 MULTI-CELLULAR LIFE WAS 1150 00:50:50,320 --> 00:50:51,800 ENTERCOLLATED TO FUNCTIONING 1151 00:50:51,800 --> 00:50:55,800 ECOSYSTEMS BUILT ON MICROBIAL 1152 00:50:55,800 --> 00:50:58,080 METABOLISMS AND THEN I ALWAYS 1153 00:50:58,080 --> 00:51:00,960 STICK THIS IN BECAUSE I TALK TO 1154 00:51:00,960 --> 00:51:02,240 BIOLOGIES THAT WHAT IS UNUSUAL 1155 00:51:02,240 --> 00:51:03,640 ABOUT THE EARTH MIGHT IN THE BE 1156 00:51:03,640 --> 00:51:07,400 THAT LIFE ORIGINATED ONLY HERE 1157 00:51:07,400 --> 00:51:11,320 BUT THAT IT HAS PERSISTED FOR 4 1158 00:51:11,320 --> 00:51:12,240 BILLION YEARS THANKS TO 1159 00:51:12,240 --> 00:51:14,520 MICROBES. SO WITH THAT, THANKS 1160 00:51:14,520 --> 00:51:17,280 VERY MUCH, I WILL STOP SHARING 1161 00:51:17,280 --> 00:51:18,840 AND MAYBE WE CAN HAVE SOME 1162 00:51:18,840 --> 00:51:20,880 DISCUSSION. 1163 00:51:20,880 --> 00:51:29,840 >> THANK YOU, VERY MUCH FOR THIS 1164 00:51:29,840 --> 00:51:34,880 EXTRAORDINARY PRESENTATION. WE 1165 00:51:34,880 --> 00:51:36,240 HAVE A WHOLE BUNCH OF QUESTIONS 1166 00:51:36,240 --> 00:51:38,200 FOR YOU, THE ONE THAT POPPED UP 1167 00:51:38,200 --> 00:51:39,880 A COUPLE OF TIMES ACTUALLY IN 1168 00:51:39,880 --> 00:51:45,080 ADVANCE OF YOUR TALK SEVERAL 1169 00:51:45,080 --> 00:51:46,920 PEOPLE SENT ME MESSAGES ASKING 1170 00:51:46,920 --> 00:51:52,760 WHAT IS YOUR DEFINITION OF LIFE 1171 00:51:52,760 --> 00:51:53,960 >> THAT IS A GREAT QUESTION. FOR 1172 00:51:53,960 --> 00:51:58,600 A LOT OF BIOLOGISTS THEY STARTED 1173 00:51:58,600 --> 00:52:02,880 TO TAKE THE CONNER STEWART VIEW 1174 00:52:02,880 --> 00:52:05,280 OF -- ONCE FAMOUSLY SAID HE 1175 00:52:05,280 --> 00:52:07,040 DIDN'T KNOW HOW TO DEFINE 1176 00:52:07,040 --> 00:52:08,240 PORNOGRAPHY BUT KNEW IT WHEN HE 1177 00:52:08,240 --> 00:52:10,240 SAW IT, I THINK A LOT OF 1178 00:52:10,240 --> 00:52:13,360 BIOLOGISTS ARE CONTENT WITH 1179 00:52:13,360 --> 00:52:14,880 THAT, PHYSICISTS AND 1180 00:52:14,880 --> 00:52:16,320 PHILOSOPHERS ARE NOT CON FIENTS 1181 00:52:16,320 --> 00:52:20,000 WITH THAT. THE DEFINITION I LIKE 1182 00:52:20,000 --> 00:52:22,000 BEST COMES FROM JERRY JOYCE OF 1183 00:52:22,000 --> 00:52:26,360 THE SCRIPS IN CALIFORNIA JERRY 1184 00:52:26,360 --> 00:52:28,640 DEFINED LIFE AS A 1185 00:52:28,640 --> 00:52:29,960 SELF-SUSTAINING CHEMICAL SYSTEM 1186 00:52:29,960 --> 00:52:32,280 CAPABLE OF DARWINIAN EVOLUTION. 1187 00:52:32,280 --> 00:52:36,800 WHAT I LOVE ABOUT THAT IS IT 1188 00:52:36,800 --> 00:52:39,000 MAKES EVOLUTION MORE OR LESS 1189 00:52:39,000 --> 00:52:42,720 DEFINITIONAL FOR LIFE. I THINK 1190 00:52:42,720 --> 00:52:45,240 THAT'S LIKELY TO HOLD NOT JUST 1191 00:52:45,240 --> 00:52:48,680 ON EARTH BUT WHEREVER WE MIGHT 1192 00:52:48,680 --> 00:52:49,480 FIND SCIENCE OF LIFE IN THE 1193 00:52:49,480 --> 00:52:52,720 UNIVERSE. -- SIGNS OF LIFE IN 1194 00:52:52,720 --> 00:52:53,040 THE UNIVERSE. 1195 00:52:53,040 --> 00:52:55,200 >> WE HAVE A QUESTION AS TO 1196 00:52:55,200 --> 00:52:57,920 WHETHER CAN LIFE BE SUSTAINED IN 1197 00:52:57,920 --> 00:53:01,760 A SULFUR CYCLE? 1198 00:53:01,760 --> 00:53:05,680 >> NOT BY ITSELF. THERE ARE 1199 00:53:05,680 --> 00:53:09,080 THINGS CALLED SULFUR REDA, CRAZY 1200 00:53:09,080 --> 00:53:11,840 ENVIRONMENTS WHERE YOU ACTUALLY 1201 00:53:11,840 --> 00:53:13,880 HAVE ALL THE ELEMENTS OF A 1202 00:53:13,880 --> 00:53:17,440 SULFUR CYCLE THAT CYCLES BACK 1203 00:53:17,440 --> 00:53:20,760 AND FORTH BETWEEN SULFIDE AND 1204 00:53:20,760 --> 00:53:25,880 SULFATE. SO YES, WE KNOW THAT 1205 00:53:25,880 --> 00:53:30,760 SULFIDE CAN BE USED TO FUEL 1206 00:53:30,760 --> 00:53:31,760 CHEMOAUTOTROPHY AND 1207 00:53:31,760 --> 00:53:35,280 PHOTOSYNTHESIS. WE KNOW SULFATE 1208 00:53:35,280 --> 00:53:39,320 CAN BE USED FOR RESPIRATION. IN 1209 00:53:39,320 --> 00:53:40,720 THAT SENSE, YES, YOU CAN HAVE A 1210 00:53:40,720 --> 00:53:44,600 LOT OF ENERGY METABOLISM DRIVEN 1211 00:53:44,600 --> 00:53:47,360 BY SULFUR CYCLE. NOW, WHAT MAKES 1212 00:53:47,360 --> 00:53:53,880 IT COMPLICATED, FOR MOST OF 1213 00:53:53,880 --> 00:53:56,920 EARTH HISTORY, THE AN AEROBIC 1214 00:53:56,920 --> 00:53:58,080 ENVIRONMENTS OR AN OXIC 1215 00:53:58,080 --> 00:54:01,520 ENVIRONMENTS OF THE OCEANS 1216 00:54:01,520 --> 00:54:03,240 WEREN'T RICH IN SILVER BUT IN 1217 00:54:03,240 --> 00:54:06,200 IRON. WE KNOW THAT BECAUSE WE 1218 00:54:06,200 --> 00:54:08,080 HAVE THESE BIG FORMATIONS CALLED 1219 00:54:08,080 --> 00:54:09,880 IRON FORMATION WHICH IS ARE 1220 00:54:09,880 --> 00:54:12,120 WHERE WE GET MOST IRON THAT HAS 1221 00:54:12,120 --> 00:54:14,400 BEEN MINED BY HUMAN. MOST OF 1222 00:54:14,400 --> 00:54:16,120 THOSE FORMED EARLY IN EARTH'S 1223 00:54:16,120 --> 00:54:20,000 HISTORY. TURNS OUT SULFUR AND 1224 00:54:20,000 --> 00:54:26,080 IRON REACT. VERY QUICKLY TO FORM 1225 00:54:26,080 --> 00:54:31,160 FOOL'S GOLD OR PYRATE. ON THIS 1226 00:54:31,160 --> 00:54:32,440 EARLY WORLD THAT DIDN'T HAVE ANY 1227 00:54:32,440 --> 00:54:34,520 OR MUCH OXYGEN, THERE WAS A LOT 1228 00:54:34,520 --> 00:54:37,920 OF IRON AND NOT MUCH SULFUR AT 1229 00:54:37,920 --> 00:54:42,760 LEAST DISSOLVED FLUIDS THAT 1230 00:54:42,760 --> 00:54:45,760 SUSTAIN BIOLOGY. SO WHILE YOU 1231 00:54:45,760 --> 00:54:49,000 COULD -- YOU HAD VERY LITTLE 1232 00:54:49,000 --> 00:54:50,080 SULFATE, SULFATE PRODUCTION 1233 00:54:50,080 --> 00:54:51,640 OCCURRED BUT IT COULDN'T HAVE 1234 00:54:51,640 --> 00:54:58,040 BEEN THE MAJOR OXIDANT. AND YOU 1235 00:54:58,040 --> 00:55:00,000 HAD SOME SULFIDE USED IN 1236 00:55:00,000 --> 00:55:01,840 PHOTOSYNTHESIS BUT PROBABLY MOST 1237 00:55:01,840 --> 00:55:04,920 SULFIDE AS SOON AS IT APPEARED 1238 00:55:04,920 --> 00:55:06,880 GOT SNAPPED IN IRON SULFIDE 1239 00:55:06,880 --> 00:55:08,520 MINERALS. IN PRINCIPLE YOU CAN 1240 00:55:08,520 --> 00:55:12,520 HAVE AN ECOSYSTEM SUSTAINED BY 1241 00:55:12,520 --> 00:55:15,280 THE ENERGETICS OF A SULFUR 1242 00:55:15,280 --> 00:55:16,560 CYCLE, IN EARTH HISTORY, IT IS A 1243 00:55:16,560 --> 00:55:17,720 LITTLE MORE COMPLICATED BECAUSE 1244 00:55:17,720 --> 00:55:21,400 OF IRON. 1245 00:55:21,400 --> 00:55:28,720 >> IS THERE RESPIRATION DURING 1246 00:55:28,720 --> 00:55:31,960 SULFUR CYCLE? 1247 00:55:31,960 --> 00:55:34,000 >> YES. SO WILL IS A WHOLE FLEET 1248 00:55:34,000 --> 00:55:37,680 OF BACTERIA THAT RESPIRE RATHER 1249 00:55:37,680 --> 00:55:40,800 THAN USING OXYGEN, THEY USE 1250 00:55:40,800 --> 00:55:43,560 SULFATE. YOU GET LESS ENERGY 1251 00:55:43,560 --> 00:55:47,760 FROM THAT REACTION. BUT I SAID 1252 00:55:47,760 --> 00:55:49,480 BRIEFLY, IT IS PROBABLY THE 1253 00:55:49,480 --> 00:55:51,440 MAJOR WAY EVEN IN THE OCEANS 1254 00:55:51,440 --> 00:55:54,400 TODAY, THAT SEDIMENTARY ORGANIC 1255 00:55:54,400 --> 00:55:56,720 MATTER IN THE OCEAN GETS 1256 00:55:56,720 --> 00:55:58,640 RECYCLED. NOW THE OCEANS TODAY 1257 00:55:58,640 --> 00:56:01,440 HAVE MORE SULFATE IN THEM THAN 1258 00:56:01,440 --> 00:56:02,600 ANY PREVIOUS TIME IN EARTH 1259 00:56:02,600 --> 00:56:04,840 HISTORY. SO IT IS AVAILABLE AS A 1260 00:56:04,840 --> 00:56:06,440 MAJOR OXIDANT WHERE OXYGEN IS 1261 00:56:06,440 --> 00:56:14,400 ABSENT. 1262 00:56:14,400 --> 00:56:15,440 >> WE HAVE ANOTHER QUESTION, 1263 00:56:15,440 --> 00:56:19,200 WHAT ARE YOUR THOUGHTS ABOUT 1264 00:56:19,200 --> 00:56:22,040 WHAT THE FIRST LIFE FORM MAY 1265 00:56:22,040 --> 00:56:24,560 HAVE ACTUALLY LOOKED LIKE. 1266 00:56:24,560 --> 00:56:30,800 >> THAT IS A GREAT QUESTION. I 1267 00:56:30,800 --> 00:56:35,280 THINK THERE IS TWO WAYS TO GO 1268 00:56:35,280 --> 00:56:36,760 ABOUT A LONG ROUNDED WAY OF 1269 00:56:36,760 --> 00:56:39,880 SAYING I DON'T KNOW. IF YOU GO 1270 00:56:39,880 --> 00:56:42,960 FROM PRESENT DAY LIFE AND GO 1271 00:56:42,960 --> 00:56:45,520 BACKWARD, YOU CAN COME TO AT 1272 00:56:45,520 --> 00:56:47,520 LEAST SOME REASONABLE 1273 00:56:47,520 --> 00:56:48,640 APPROXIMATION OF WHAT THE LAST 1274 00:56:48,640 --> 00:56:53,560 COMMON ANCESTOR OF LIFE WAS 1275 00:56:53,560 --> 00:57:03,520 LIKE. DNA AND GENETIC CYCLES NOT 1276 00:57:03,520 --> 00:57:10,440 UNLIKE WHAT WE SEE TODAY, 1277 00:57:10,440 --> 00:57:11,640 MEMBRANES WE SEE TODAY. THE 1278 00:57:11,640 --> 00:57:12,680 PROBLEM IS THAT IS NOT THE FIRST 1279 00:57:12,680 --> 00:57:16,680 LIFE, THAT STUFF IS THE PRODUCT 1280 00:57:16,680 --> 00:57:18,360 OF SUBSTANTIAL INTERVAL OF 1281 00:57:18,360 --> 00:57:23,200 EVOLUTIEVOLUTION. THE FIRST LIFE 1282 00:57:23,200 --> 00:57:27,240 ARE TWO CAMPS, I MUST ADMIT MY 1283 00:57:27,240 --> 00:57:31,120 WORK IS MORE CONCERNED HOW WE 1284 00:57:31,120 --> 00:57:32,800 SEE RECORDS FOR LIFE ONCE 1285 00:57:32,800 --> 00:57:34,360 ESTABLISHED BUT FRIENDS DO 1286 00:57:34,360 --> 00:57:38,600 ORIGIN OF LIFE WORK. THE FIRST 1287 00:57:38,600 --> 00:57:40,000 THING JERRY JOYCE CALL LIFE THAT 1288 00:57:40,000 --> 00:57:44,000 IS EVOLVING SELF-SUSTAINING 1289 00:57:44,000 --> 00:57:48,040 SYSTEMS ARE RNA, RNA LIKE 1290 00:57:48,040 --> 00:57:48,960 MOLECULE WE HAVE KNOWN SINCE 1291 00:57:48,960 --> 00:57:53,840 WORK OF TOM CHECK THAT RNA IS 1292 00:57:53,840 --> 00:57:59,960 NOT SIMPLY THE MIDWIFE FOR 1293 00:57:59,960 --> 00:58:02,760 PRODUCTION OF PROTEINS. BUT CAN 1294 00:58:02,760 --> 00:58:06,840 WORK AS AN ENZYME ITSELF, CALLED 1295 00:58:06,840 --> 00:58:11,720 RIBOSOMES. RIBOSYMES. SO ONE 1296 00:58:11,720 --> 00:58:13,880 CAMP SEES EARLY SELF-SUSTAINING 1297 00:58:13,880 --> 00:58:17,040 SYSTEMS BEING BASED ON NUCLEIC 1298 00:58:17,040 --> 00:58:21,720 ACIDS THAT ARE BOTH 1299 00:58:21,720 --> 00:58:26,040 INFORMATIONAL ENSIGH MATTIC. 1300 00:58:26,040 --> 00:58:29,760 THAT HAS A -- ENZYME ATTIC. THAT 1301 00:58:29,760 --> 00:58:32,480 IS A PROBLEM HOW WE INCORPORATE 1302 00:58:32,480 --> 00:58:33,800 PROTEIN IN THE LIFE THAT MUST 1303 00:58:33,800 --> 00:58:34,840 HAVE BEEN PRESENT IN THE LAST 1304 00:58:34,840 --> 00:58:36,560 COMMON ANCESTOR. THERE IS A 1305 00:58:36,560 --> 00:58:38,280 LOYAL OPPOSITION. PEOPLE WHO 1306 00:58:38,280 --> 00:58:41,600 TEND TO SEE LIFE AS BEGINNING AT 1307 00:58:41,600 --> 00:58:47,600 HYDRO THERMAL VENTS IN THE OCEAN 1308 00:58:47,600 --> 00:58:50,200 WHERE ONE SEES YOU CAN HAVE 1309 00:58:50,200 --> 00:58:54,200 POSITION WHERE YOU GET THESE 1310 00:58:54,200 --> 00:58:59,800 STRONG PH GRADIENTS DEVELOPING 1311 00:58:59,800 --> 00:59:00,680 AND YOU HAVE SOMETHING SIMILAR 1312 00:59:00,680 --> 00:59:04,480 TO THE KINDS OF CELLULAR 1313 00:59:04,480 --> 00:59:07,840 PROCESSES THAT GIVE RISE TO 1314 00:59:07,840 --> 00:59:10,520 METABOLISM TODAY UNDER PLAUSIBLE 1315 00:59:10,520 --> 00:59:12,120 PREBIOTIC CONDITIONS PEOPLE HAVE 1316 00:59:12,120 --> 00:59:16,240 BEEN ABLE TO SYNTHESIZE A NUMBER 1317 00:59:16,240 --> 00:59:18,800 OF CONSTITUENT PARTS OF THE KREB 1318 00:59:18,800 --> 00:59:21,960 PSYCH. BOTH OF THESE THINGS ARE 1319 00:59:21,960 --> 00:59:25,680 INTERESTING, THEY BOTH GIVE US 1320 00:59:25,680 --> 00:59:28,000 SOME ENSIGHT. THEY BOTH -- 1321 00:59:28,000 --> 00:59:29,240 INSIGHT. THEY SUFFER FROM THE 1322 00:59:29,240 --> 00:59:32,120 DIFFICULTY OF GETTING AN 1323 00:59:32,120 --> 00:59:33,520 INTEGRATION BETWEEN NUCLEIC ACID 1324 00:59:33,520 --> 00:59:35,440 AND PROTEINS THAT IS PRESENT IN 1325 00:59:35,440 --> 00:59:38,560 ALL LIFE THAT WE KNOW. THAT IS 1326 00:59:38,560 --> 00:59:42,080 PRETTY MUCH WHERE WE ARE. WE 1327 00:59:42,080 --> 00:59:43,480 KNOW IT MUST HAVE HAPPENED THERE 1328 00:59:43,480 --> 00:59:45,560 BUT HOW WE GET THERE WE REMAIN 1329 00:59:45,560 --> 00:59:51,600 IN SUBSTANTIAL IGNORANCE. 1330 00:59:51,600 --> 00:59:56,880 >> SUGGESTING THAT ENERGY 1331 00:59:56,880 --> 00:59:57,640 RECEDES GENES. 1332 00:59:57,640 --> 01:00:04,240 >> DEPENDS WHO YOU TALK TO I 1333 01:00:04,240 --> 01:00:06,080 WENT TO A MEETING IN JAPAN A FEW 1334 01:00:06,080 --> 01:00:07,320 YEARS AGO AND ONE OF THE NUCLEIC 1335 01:00:07,320 --> 01:00:09,520 ACID PEOPLE CAME UP TO ME AND HE 1336 01:00:09,520 --> 01:00:14,600 SAID WELL, YOU KNOW, YOU CAN 1337 01:00:14,600 --> 01:00:15,880 HAVE LIFE WITHOUT ENERGY 1338 01:00:15,880 --> 01:00:18,400 METABOLISM AND MY RESPONSE IS 1339 01:00:18,400 --> 01:00:20,040 YEAH, IT IS PROBABLY TRUE BUT 1340 01:00:20,040 --> 01:00:22,240 LIFE BECOMES INTERESTING WHEN IT 1341 01:00:22,240 --> 01:00:24,560 HAS ENERGY METABOLISM, THAT'S 1342 01:00:24,560 --> 01:00:25,680 WHEN IT STARTS INTERACTING WITH 1343 01:00:25,680 --> 01:00:29,480 THE EARTH IN A SUBSTANTIAL WAY. 1344 01:00:29,480 --> 01:00:35,080 >> IF WE DON'T HAVE A CELL 1345 01:00:35,080 --> 01:00:40,720 ENCOMPASSED BY MEMBRANE, IN AWE 1346 01:00:40,720 --> 01:00:43,760 PRESENT KNOWLEDGE CAN A GENE 1347 01:00:43,760 --> 01:00:46,480 FUNCTION IN AN EXRA CELLULAR 1348 01:00:46,480 --> 01:00:46,760 MILIEU? 1349 01:00:46,760 --> 01:00:51,000 >> THAT IS AN IMPORTANT 1350 01:00:51,000 --> 01:00:53,320 QUESTION. WHILE SOME HAVE DONE 1351 01:00:53,320 --> 01:00:58,120 TEST TUBE EXPERIMENTS, THAT 1352 01:00:58,120 --> 01:01:00,440 SUGGEST YOU CAN GET SOMETHING 1353 01:01:00,440 --> 01:01:04,440 CLOSE TO SELF-REPLICATION YOU 1354 01:01:04,440 --> 01:01:08,440 CAN HAVE TWO RECIPROCAL RNA 1355 01:01:08,440 --> 01:01:09,440 MOLECULES THAT ESSENTIALLY 1356 01:01:09,440 --> 01:01:10,840 CATALYZE THE REPLICATION OF THE 1357 01:01:10,840 --> 01:01:15,360 OTHER. ON THE OTHER HAND A 1358 01:01:15,360 --> 01:01:20,920 NUMBER OF PEOPLE INCLUDING MY 1359 01:01:20,920 --> 01:01:22,000 FRIEND JACK VAN MORE TRYING TO 1360 01:01:22,000 --> 01:01:25,840 CARRY OUT THESE REACTIONS WITHIN 1361 01:01:25,840 --> 01:01:30,320 A MEMBRANE ENCLOSURE. A, IT 1362 01:01:30,320 --> 01:01:34,440 SEEMS TO MAKE THEM WORK BETTER 1363 01:01:34,440 --> 01:01:36,480 BECAUSE YOU DON'T HAVE DILUTION 1364 01:01:36,480 --> 01:01:38,160 IF NOTHING ELSE. TURNS OUT ONE 1365 01:01:38,160 --> 01:01:41,320 THING THAT IS DIRT EASY TO MAKE 1366 01:01:41,320 --> 01:01:45,560 ON THE EARLY EARTH WHO ARE LIPID 1367 01:01:45,560 --> 01:01:47,320 MICELLS, THAT ALL YOU NEED IS 1368 01:01:47,320 --> 01:01:49,400 PREBIOTIC REACTS THAT MAKE FATTY 1369 01:01:49,400 --> 01:01:53,160 ACIDS AND THINGS LIKE THAT. IF 1370 01:01:53,160 --> 01:01:55,160 YOU SPLASH THEM THEY WILL 1371 01:01:55,160 --> 01:01:57,480 SELF-ORGANIZE INTO LIPID 1372 01:01:57,480 --> 01:01:58,760 ENVIRONMENTS, PEOPLE LIKE DAVID 1373 01:01:58,760 --> 01:02:00,400 DEEMER IN CALIFORNIA HAVE 1374 01:02:00,400 --> 01:02:03,200 ACTUALLY SHOWN THAT IF YOU 1375 01:02:03,200 --> 01:02:05,640 REPEATEDLY WET AND DRY SOME OF 1376 01:02:05,640 --> 01:02:07,040 THESE SYSTEMS THAT ORIGINATE 1377 01:02:07,040 --> 01:02:12,600 WITH LIPIDS HERE AND NUCLEIC 1378 01:02:12,600 --> 01:02:14,640 ACIDS OVER HERE YOU HAVE SYSTEMS 1379 01:02:14,640 --> 01:02:16,640 IN WHICH NUCLEIC ACID MOLECULES 1380 01:02:16,640 --> 01:02:19,000 ARE ACTUALLY ENCAPSULATED WITHIN 1381 01:02:19,000 --> 01:02:23,160 THE LIPIDS. IT IS VERY 1382 01:02:23,160 --> 01:02:26,320 IMPORTANT AND I THINK SOME SORT 1383 01:02:26,320 --> 01:02:30,840 OF EARLY SIMPLE LIPID ONE PART 1384 01:02:30,840 --> 01:02:32,400 OF EVOLVING SYSTEM VERY, VERY 1385 01:02:32,400 --> 01:02:38,880 EARLY. 1386 01:02:38,880 --> 01:02:42,560 >> DAN SENT A QUESTION IT SOUNDS 1387 01:02:42,560 --> 01:02:44,920 AS IF BILLIONS OF YEARS WERE 1388 01:02:44,920 --> 01:02:52,920 REQUIRED FOR EUKARYOTS TO E 1389 01:02:52,920 --> 01:02:54,120 INVOLVE ON OTHER PLANETS IN THE 1390 01:02:54,120 --> 01:02:56,000 UNIVERSE. CAN YOU IMAGINE A 1391 01:02:56,000 --> 01:02:58,520 CIRCUMSTANCE IN WHICH IN PROCESS 1392 01:02:58,520 --> 01:03:01,840 WOULD OCCUR FASTER? 1393 01:03:01,840 --> 01:03:05,880 >> YES. GOOD QUESTION, DAN. I'M 1394 01:03:05,880 --> 01:03:13,360 JUST BEEN -- ONE OF MY SIDE JOBS 1395 01:03:13,360 --> 01:03:15,840 I REVIEW BOOKS FOR LONDON TIMES 1396 01:03:15,840 --> 01:03:18,200 I REVIEWED A BOOK CALLED 1397 01:03:18,200 --> 01:03:21,280 POSSIBILITY OF LIFE BY JAMIE 1398 01:03:21,280 --> 01:03:24,640 GREEN. IT IS THIS WONDERFUL 1399 01:03:24,640 --> 01:03:27,040 INFORMATIVE BOOK ABOUT HOW WE 1400 01:03:27,040 --> 01:03:30,640 MIGHT THINK ABOUT LIFE BEYOND 1401 01:03:30,640 --> 01:03:32,960 THE EARTH THE REASON RELEVANT 1402 01:03:32,960 --> 01:03:36,480 HERE IS THAT MANY PEOPLE WILL 1403 01:03:36,480 --> 01:03:39,000 TALK ABOUT HOW THERE IS A LOW 1404 01:03:39,000 --> 01:03:42,520 PROBABILITY OF ACHIEVING 1405 01:03:42,520 --> 01:03:46,040 EUKARYOTS OR MULTI-CELLULARITY 1406 01:03:46,040 --> 01:03:48,080 OR LOW LOAN INTELLIGENCE, 1407 01:03:48,080 --> 01:03:52,120 TECHNOLOGICAL HUMANS ARE JUST A 1408 01:03:52,120 --> 01:03:54,120 WHISPER OF INTERVAL OF HISTORY. 1409 01:03:54,120 --> 01:03:57,400 BUT THE TIME SCALE OF EVOLUTION, 1410 01:03:57,400 --> 01:04:01,320 I THINK IN MANY WAYS IS 1411 01:04:01,320 --> 01:04:03,560 CONSTRAIND BY TIME SCALE OF 1412 01:04:03,560 --> 01:04:06,560 EARTH OXYGEN HISTORY. ON ANOTHER 1413 01:04:06,560 --> 01:04:11,200 PLANET, WE MIGHT HAVE GOTTEN 1414 01:04:11,200 --> 01:04:13,320 OXYGEN MUCH MORE QUICK, WHICH 1415 01:04:13,320 --> 01:04:15,480 BARRIERS TO EUKARYOTS AND 1416 01:04:15,480 --> 01:04:18,120 ULTIMATELY COMPLEX 1417 01:04:18,120 --> 01:04:21,040 MULTI-CELLULARITY, WERE LIFTED 1418 01:04:21,040 --> 01:04:23,200 SO ALTHOUGH IT TOOK FOUR AND A 1419 01:04:23,200 --> 01:04:26,480 HALF BILLION YEARS TO GET FROM 1420 01:04:26,480 --> 01:04:30,000 REAL LIFE TO US ON EARTH, I'M 1421 01:04:30,000 --> 01:04:32,240 NOT SURE THAT IS ANYTHING LIKE A 1422 01:04:32,240 --> 01:04:33,320 FUNDAMENTAL TIME SCALE. 1423 01:04:33,320 --> 01:04:35,880 I THINK IT IS AS MUCH A PRODUCT 1424 01:04:35,880 --> 01:04:38,640 OF PLANETARY HISTORY AS IT IS 1425 01:04:38,640 --> 01:04:43,400 BIOLOGICAL POSSIBILITY. 1426 01:04:43,400 --> 01:04:48,320 >> YOU TALKED GREAT OXIDATION 1427 01:04:48,320 --> 01:04:53,600 EVENT. IS THERE EVIDENCE OX 1428 01:04:53,600 --> 01:04:55,680 GENERAL COULD HAVE BEEN 1429 01:04:55,680 --> 01:05:00,120 INTRODUCED AS SLOWER RATE, 1430 01:05:00,120 --> 01:05:04,880 SMALLER AMOUNTS PRODUCING GARAGE 1431 01:05:04,880 --> 01:05:06,840 WOULD BACTERIAL AND OTHER? IS 1432 01:05:06,840 --> 01:05:09,760 THERE ANY EVIDENCE FOR THAT 1433 01:05:09,760 --> 01:05:13,600 >> THAT IS A GOOD QUESTION AND 1434 01:05:13,600 --> 01:05:16,240 INTERESTING PATTERN THERE ARE 1435 01:05:16,240 --> 01:05:20,080 FOUR OR FIVE LINES OF 1436 01:05:20,080 --> 01:05:23,680 GEOCHEMICAL EVIDENCE THAT ALL 1437 01:05:23,680 --> 01:05:26,160 AGREE OXYGEN TENSION BEFORE 1438 01:05:26,160 --> 01:05:29,400 2.4 BILLION YEARS AGO HAD TO BE 1439 01:05:29,400 --> 01:05:32,200 VERY LOW. THERE IS MASS 1440 01:05:32,200 --> 01:05:33,040 INDEPENDENT FRACTS NATION OF 1441 01:05:33,040 --> 01:05:38,240 SULFUR ISOTOPES. WHICH BASICALLY 1442 01:05:38,240 --> 01:05:41,960 SHOWS THAT THERE ARE SOME 1443 01:05:41,960 --> 01:05:43,000 PHOTOCHEMICAL PROCESSES THAT 1444 01:05:43,000 --> 01:05:44,880 WILL OCCUR IN THE ATMOSPHERE 1445 01:05:44,880 --> 01:05:48,360 WHEN OXYGEN IS ESSENTIALLY 1446 01:05:48,360 --> 01:05:52,640 ABSENT THAT CAUSE FRACTIONATIONS 1447 01:05:52,640 --> 01:05:54,760 AMONG THE FOUR STABLE ISOTOPES 1448 01:05:54,760 --> 01:05:58,280 OF SULFUR THAT DIFFER FROM THOSE 1449 01:05:58,280 --> 01:06:02,200 THAT ARE CHARACTERISTIC OF 1450 01:06:02,200 --> 01:06:04,400 BIOLOGY. MODELING SUGGESTS THAT 1451 01:06:04,400 --> 01:06:07,280 THAT WILL ONLY HAPPEN IF OXYGEN 1452 01:06:07,280 --> 01:06:08,680 TENSION IN THE ATMOSPHERE ARE 1453 01:06:08,680 --> 01:06:11,160 SOMETHING LIKE TEN TO THE 1454 01:06:11,160 --> 01:06:12,520 NEGATIVE 6 OF PRESENT DAY VALUE 1455 01:06:12,520 --> 01:06:14,280 SO VERY LOW, TOO LOW FOR 1456 01:06:14,280 --> 01:06:18,600 METABOLISM. THAT SEEMS TO 1457 01:06:18,600 --> 01:06:22,560 CHANGE. AND CHANGE DRAMATICALLY 1458 01:06:22,560 --> 01:06:26,680 AND FOREVER BETWEEN 2.4 AND 1459 01:06:26,680 --> 01:06:29,600 2.2 BILLION YEARS AGO. HAVING 1460 01:06:29,600 --> 01:06:34,640 SAID THAT, THERE ARE NUMBER OF 1461 01:06:34,640 --> 01:06:36,040 REPORTS IN OLDER BLOCKS OF WHAT 1462 01:06:36,040 --> 01:06:38,080 HAVE BEEN CALLED WHIFFS OF 1463 01:06:38,080 --> 01:06:40,240 OXYGEN, THERE COULD HAVE BEEN 1464 01:06:40,240 --> 01:06:43,640 SOME LOCAL TRANSIENT SMALL 1465 01:06:43,640 --> 01:06:47,320 ACCUMULATION OF OXYGEN IN SOME 1466 01:06:47,320 --> 01:06:54,960 OCEANS PERHAPS LAKES. THAT 1467 01:06:54,960 --> 01:06:57,680 SUGGEST THE CAPACITY FOR OXYGEN 1468 01:06:57,680 --> 01:07:00,760 PHOTO SYNTHESIS EXISTED BUT 1469 01:07:00,760 --> 01:07:01,840 EITHER BECAUSE TOTAL RATES OF 1470 01:07:01,840 --> 01:07:03,480 PRIMARY PRODUCTION WERE VERY 1471 01:07:03,480 --> 01:07:07,600 LOW, DUE TO NUTRIENT STARVATION 1472 01:07:07,600 --> 01:07:12,960 OR THERE IS ENOUGH IRON AROUND 1473 01:07:12,960 --> 01:07:15,440 THAT PBS SYNTHETIC BACTERIAER 1474 01:07:15,440 --> 01:07:16,800 OTHER TYPES FAVORED ARE STILL IN 1475 01:07:16,800 --> 01:07:22,120 ARGUMENT BUT IT SUGGESTS THE 1476 01:07:22,120 --> 01:07:24,480 CAPACITY FOR OXYGENIC 1477 01:07:24,480 --> 01:07:26,360 PHOTOSYNTHESIS, THE FIRST OXYGEN 1478 01:07:26,360 --> 01:07:29,760 PRODUCING CYANO BACTERIA EXISTED 1479 01:07:29,760 --> 01:07:35,560 LONG BEFORE THERE WAS THIS GREAT 1480 01:07:35,560 --> 01:07:37,080 CHANGE IN THE ATMOSPHERE, AS I 1481 01:07:37,080 --> 01:07:39,840 MENTION BRIEFLY, A MAJOR CULPRIT 1482 01:07:39,840 --> 01:07:43,360 EXPLAINING THAT CHANGE IS THAT 1483 01:07:43,360 --> 01:07:45,240 IT IS ABOUT -- ONLY ABOUT THE 1484 01:07:45,240 --> 01:07:51,200 TIME OF GREAT OXYGENATION EVENT 1485 01:07:51,200 --> 01:07:52,080 THAT WE HAVE EVIDENCE THAT 1486 01:07:52,080 --> 01:07:53,920 CONTINUE INNOCENCE EMERGED ABOVE 1487 01:07:53,920 --> 01:07:56,880 SEA LEVEL IN A SUBSTANTIAL WAY. 1488 01:07:56,880 --> 01:08:00,520 THE REASON FOR THAT IS THAT WHEN 1489 01:08:00,520 --> 01:08:06,120 YOU HAVE A HOT MANTEL TWO THINGS 1490 01:08:06,120 --> 01:08:11,800 HAPPEN. ONE IS IT CAN'T SUPPORT 1491 01:08:11,800 --> 01:08:14,480 CONTINUE INNOCENCE WITH THIS 1492 01:08:14,480 --> 01:08:17,120 ISOSTATIC RELATIONSHIPS WE SEE 1493 01:08:17,120 --> 01:08:19,080 TODAY. CONTINUE INNOCENCE WOULD 1494 01:08:19,080 --> 01:08:22,280 BE HIGH ABOVE SEA LEVEL AND ALSO 1495 01:08:22,280 --> 01:08:23,840 THIS IS NEAT, A COLLEAGUE OF 1496 01:08:23,840 --> 01:08:25,880 MINE REBECCA FISHER HAS DONE 1497 01:08:25,880 --> 01:08:29,240 THIS NICE WORK SHOWING THAT A 1498 01:08:29,240 --> 01:08:33,120 HOT MANTEL CANNOT ACTUALLY 1499 01:08:33,120 --> 01:08:36,400 RETAIN MUCH WATER IN IT. SO 1500 01:08:36,400 --> 01:08:38,640 TODAY WE THINK THERE IS AN 1501 01:08:38,640 --> 01:08:40,520 OCEAN'S WORTH OF WATER IN THE 1502 01:08:40,520 --> 01:08:42,880 MANTEL PERHAPS SEVERAL OCEANS 1503 01:08:42,880 --> 01:08:47,360 WORTH OF MANTEL. ON THE EARLY 1504 01:08:47,360 --> 01:08:50,040 EARTH WHEN MANTEL WAS HOT MOST 1505 01:08:50,040 --> 01:08:51,200 OF THAT HAVE WOULD HAVE BEEN 1506 01:08:51,200 --> 01:08:52,480 DEGASSED SO IT COULD BE THAT YOU 1507 01:08:52,480 --> 01:08:56,680 HAVE MUCH MORE SEA WATER 3 OR 4 1508 01:08:56,680 --> 01:08:58,480 BILLION YEARS AGO THAN TODAY AND 1509 01:08:58,480 --> 01:09:02,160 AS THE MANTEL COOL PLATE 1510 01:09:02,160 --> 01:09:03,320 TECTONICS BRING SOME OF THAT 1511 01:09:03,320 --> 01:09:05,360 WATER BACK THE MANTEL AND KEEP 1512 01:09:05,360 --> 01:09:06,640 IT THERE, THAT WE GOT 1513 01:09:06,640 --> 01:09:07,360 RELATIONSHIPS BETWEEN CONTINUE 1514 01:09:07,360 --> 01:09:08,360 INNOCENCE AND OCEANS WE SEE 1515 01:09:08,360 --> 01:09:13,680 TODAY. IN A NUTSHELL, THERE'S 1516 01:09:13,680 --> 01:09:17,640 REASON TO BELIEVE THE TIMING AND 1517 01:09:17,640 --> 01:09:21,360 SOME OF THE DYNAMICS THIS 1518 01:09:21,360 --> 01:09:25,240 OXYGENATION EVENT OWE A DEBT TO 1519 01:09:25,240 --> 01:09:28,200 EARTH EVOLVING TECTONIC REGIMES. 1520 01:09:28,200 --> 01:09:30,040 >> WE HAVE A QUESTION I WANT TO 1521 01:09:30,040 --> 01:09:31,680 READ TO YOU, BECAUSE IT IS FROM 1522 01:09:31,680 --> 01:09:40,280 ONE OF YOUR FORMER STUDENTS. 1523 01:09:40,280 --> 01:09:41,160 FROM HENRY LEEVINE DISTINGUISHED 1524 01:09:41,160 --> 01:09:42,560 SCIENTIST HERE AT THE NATIONAL 1525 01:09:42,560 --> 01:09:45,160 INSTITUTES OVERMELT. HANK 1526 01:09:45,160 --> 01:09:47,000 WRITES, THANK YOU FOR YOUR 1527 01:09:47,000 --> 01:09:49,520 WONDERFUL LECTURE. JUST AS 1528 01:09:49,520 --> 01:09:53,960 COMPELLING AS YOUR LECTURES AT 1529 01:09:53,960 --> 01:09:57,480 OVERLAND WERE WHICH I LOVE, WHEN 1530 01:09:57,480 --> 01:10:00,160 YOU COMMENT ON THE CHEMICAL 1531 01:10:00,160 --> 01:10:09,000 NATURE OF ORGANICS DENTED ON 1532 01:10:09,000 --> 01:10:12,560 MARS AND SCIENCE OF PAST LIFE 1533 01:10:12,560 --> 01:10:14,880 AND YOU WILL ALSO COMMENT ON THE 1534 01:10:14,880 --> 01:10:17,960 QUOTE MICROFOSSILS CLOSE QUOTE, 1535 01:10:17,960 --> 01:10:23,080 FOUND IN METEOR ITS SAID TO BE 1536 01:10:23,080 --> 01:10:23,360 FROM MARS. 1537 01:10:23,360 --> 01:10:25,640 >> FIRST OF ALL I'M GLAD TO HEAR 1538 01:10:25,640 --> 01:10:26,440 YOU HAVE GONE ON TO GREAT 1539 01:10:26,440 --> 01:10:28,480 THINGS. THAT'S WHAT WE EXPECT 1540 01:10:28,480 --> 01:10:30,320 FROM OUR OVERLAND STUDENTS. 1541 01:10:30,320 --> 01:10:32,880 THOSE ARE GOOD QUESTIONS. AND I 1542 01:10:32,880 --> 01:10:36,520 CAN COMMENT ON BOTH. I'M SORRY 1543 01:10:36,520 --> 01:10:42,440 IF I HAVE TO POUR WATER ON 1544 01:10:42,440 --> 01:10:44,680 WI-FIES HERE BUT YES, THERE DOES 1545 01:10:44,680 --> 01:10:49,600 -- BIOPHYLES. BUT THERE DOES NOW 1546 01:10:49,600 --> 01:10:50,600 APPEAR TO BE REASONABLE 1547 01:10:50,600 --> 01:10:53,000 DETECTION OF ORGANIC MOLECULES 1548 01:10:53,000 --> 01:10:56,400 ON MARS. THAT IS EXCITING. THE 1549 01:10:56,400 --> 01:10:57,840 PROBLEM IS THERE IS AT LEAST 1550 01:10:57,840 --> 01:10:59,240 THREE DIFFERENT WAYS THOSE 1551 01:10:59,240 --> 01:10:59,960 MOLECULES COULD HAVE BEEN GOTTEN 1552 01:10:59,960 --> 01:11:02,080 THERE. -- COULD HAVE GOTTEN 1553 01:11:02,080 --> 01:11:05,040 THERE. THEY COULD HAVE 1554 01:11:05,040 --> 01:11:06,280 ORIGINATED FROM LIVING IS ALSO. 1555 01:11:06,280 --> 01:11:08,240 WE CAN'T RULE THAT OUT. ON THE 1556 01:11:08,240 --> 01:11:12,120 OTHER HAND, THERE IS NOTHING IN 1557 01:11:12,120 --> 01:11:15,160 THE COMPOSITION OF THE MOLECULES 1558 01:11:15,160 --> 01:11:17,400 THAT HAVE BEEN DISCOVERED THAT 1559 01:11:17,400 --> 01:11:21,320 WOULD MANDATE THAT. IT COULD BE 1560 01:11:21,320 --> 01:11:25,120 THAT THERE WAS PREBIOTIC HISTORY 1561 01:11:25,120 --> 01:11:26,600 ON MARS THE WAY THERE MUST HAVE 1562 01:11:26,600 --> 01:11:28,520 BEEN ON EARTH THAT LED TO LIFE 1563 01:11:28,520 --> 01:11:30,800 SO THERE ARE -- WE KNOW FROM THE 1564 01:11:30,800 --> 01:11:31,920 (INAUDIBLE) EXPERIMENT BACK IN 1565 01:11:31,920 --> 01:11:34,680 THE 1950s, THAT IT IS UNDER 1566 01:11:34,680 --> 01:11:35,520 THE RIGHT CONDITIONS WHICH 1567 01:11:35,520 --> 01:11:37,200 INCLUDE NO OXYGEN, BY THE WAY, 1568 01:11:37,200 --> 01:11:39,040 IT IS FAIRLY EASY TO MAKE 1569 01:11:39,040 --> 01:11:41,160 ORGANIC MOLECULES INCLUDING 1570 01:11:41,160 --> 01:11:45,040 AMINO ACIDS FROM ALL YOU NEED IS 1571 01:11:45,040 --> 01:11:46,720 ENERGY AND SIMPLE INORGANIC 1572 01:11:46,720 --> 01:11:49,360 MOLECULES. THEN THE THIRD 1573 01:11:49,360 --> 01:11:51,080 POSSIBILITY, MARS IS CONSTANTLY 1574 01:11:51,080 --> 01:11:54,960 BOMBARDED BY METEORIT EXS AND 1575 01:11:54,960 --> 01:11:56,520 WITH KNOW THERE ARE CLASSES OF 1576 01:11:56,520 --> 01:11:58,160 METEORITES THAT CONTAIN UP TO 1577 01:11:58,160 --> 01:12:02,600 20% ORGANIC MATTER SO 1578 01:12:02,600 --> 01:12:04,440 CARBONATION THOSE METEORITES 1579 01:12:04,440 --> 01:12:05,720 WERE PROBABLY IMPORTANT FOR 1580 01:12:05,720 --> 01:12:07,720 BRINGING THINGS LIKE CARBON AND 1581 01:12:07,720 --> 01:12:10,560 WATER TO THE EARTH WHEN EARTH 1582 01:12:10,560 --> 01:12:12,360 FORMED. SO YES WE HAVE THESE 1583 01:12:12,360 --> 01:12:15,680 MOLECULES. THINK THAT IS A TOUR 1584 01:12:15,680 --> 01:12:18,000 D E FORCE DETECTION BY MY 1585 01:12:18,000 --> 01:12:22,160 COLLEAGUES ON THE PERSEVERANCE 1586 01:12:22,160 --> 01:12:23,760 SCIENCE TEAM AS NAY ARE CAREFUL 1587 01:12:23,760 --> 01:12:26,560 TO POINT OUTS, THERE'S STILL 1588 01:12:26,560 --> 01:12:28,640 MUCH UNCERTAINTY AS TO THE 1589 01:12:28,640 --> 01:12:32,640 PROVIDENCE OF THOSE. THE OTHER 1590 01:12:32,640 --> 01:12:36,600 QUESTION WAS PAPER PUBLISHED IN 1591 01:12:36,600 --> 01:12:40,000 1996 WHICH TOOK -- LOOKED AT A 1592 01:12:40,000 --> 01:12:41,640 METEORITE INTERPRETED AS 1593 01:12:41,640 --> 01:12:44,280 ORIGINATING ON MARS AND FOUND 1594 01:12:44,280 --> 01:12:46,880 WHAT WERE DESCRIBED AS 1595 01:12:46,880 --> 01:12:48,480 MICROFOSSILS. THERE ARE THREE OR 1596 01:12:48,480 --> 01:12:51,440 FOUR LINES OF EVIDENCE INDUCED 1597 01:12:51,440 --> 01:12:53,680 TO MATERIALS IN THAT METEORITE 1598 01:12:53,680 --> 01:12:55,880 AS BEING PIE LOGICAL. TURNS OUT 1599 01:12:55,880 --> 01:12:57,800 THE CONTROVERSIAL PART OF THAT 1600 01:12:57,800 --> 01:12:59,400 IS NOT WHETHER THE METEORITE 1601 01:12:59,400 --> 01:13:00,800 COMES FROM MARS, THERE'S SOME 1602 01:13:00,800 --> 01:13:02,560 FEATURES OF THE CHEMISTRY OF 1603 01:13:02,560 --> 01:13:06,800 THAT METEORITE MAKE IT CLEAR 1604 01:13:06,800 --> 01:13:08,800 MARS IS MOST LIKELY PLACE OF 1605 01:13:08,800 --> 01:13:12,920 ORIGIN FOR IT, PROBABLY KNOCKED 1606 01:13:12,920 --> 01:13:15,320 OFF BY IMPACT PUTTING SOME 1607 01:13:15,320 --> 01:13:17,120 MATERIALS INTO BALLISTIC ORBIT 1608 01:13:17,120 --> 01:13:19,680 AND FOUND THEIR WAY TO EARTH. 1609 01:13:19,680 --> 01:13:21,880 THE CONTROVERSIAL PART IS 1610 01:13:21,880 --> 01:13:23,680 WHETHER THERE IS ANY REASON TO 1611 01:13:23,680 --> 01:13:26,760 CONSIDER BIOLOGY AS BEING 1612 01:13:26,760 --> 01:13:28,560 IMPORTANT IN THIS. I THINK MOST 1613 01:13:28,560 --> 01:13:30,880 PEOPLE WITH THE CONSPICUOUS 1614 01:13:30,880 --> 01:13:32,440 EXCEPTION PEOPLE WHO WROTE THE 1615 01:13:32,440 --> 01:13:39,240 PAPER IN THE FIRST PLACE SAY 1616 01:13:39,240 --> 01:13:42,760 AABOOTIOTIC PROCESSES ARE MORE 1617 01:13:42,760 --> 01:13:45,400 THAN SUFFICIENT TO EXPLAIN 1618 01:13:45,400 --> 01:13:46,720 EVERYTHING THAT WERE ORIGINALLY 1619 01:13:46,720 --> 01:13:48,840 DEDUCED TO BIOLOGY. SO AT 1620 01:13:48,840 --> 01:13:53,360 PRESENT LEVEL OF UNDERSTANDING 1621 01:13:53,360 --> 01:13:58,200 WE HAVE NO UNAMBIGUOUS OR 1622 01:13:58,200 --> 01:14:00,920 STRONGLY SUGGEST EVIDENCE FOR 1623 01:14:00,920 --> 01:14:03,320 LIFE ON MARS. WE CAN'T RULE OUT 1624 01:14:03,320 --> 01:14:05,920 IT MAY HAVE BEEN THERE. ONE 1625 01:14:05,920 --> 01:14:09,000 OTHER THING WEARING MY MARS HAT, 1626 01:14:09,000 --> 01:14:13,000 A VERY GOOD COLLEAGUE OF MINE AN 1627 01:14:13,000 --> 01:14:14,320 ATMOSPHERIC MODELER, I PUBLISHED 1628 01:14:14,320 --> 01:14:17,480 A PAPER LAST YEAR IN WHICH WE 1629 01:14:17,480 --> 01:14:20,040 LOOK AT THE RECORD OF TEMPERATE 1630 01:14:20,040 --> 01:14:21,360 ENVIRONMENTS AND WATER ON MARS 1631 01:14:21,360 --> 01:14:25,120 THROUGH TIME, AND EVERYONE WOULD 1632 01:14:25,120 --> 01:14:26,960 AGREE THAT MARS WAS ONCE WETTER 1633 01:14:26,960 --> 01:14:28,720 AND WARMER THAN IT IS NOW AND 1634 01:14:28,720 --> 01:14:31,160 THEN THROUGH TIME BASICALLY 1635 01:14:31,160 --> 01:14:39,480 BECAME THIS DECEM DESOLATE PLACE 1636 01:14:39,480 --> 01:14:41,120 TODAY. OUR MODELING STRONGLY 1637 01:14:41,120 --> 01:14:42,520 SUGGEST THAT IT WASN'T THE CASE 1638 01:14:42,520 --> 01:14:46,120 THAT MARS WAS CLIMATE FOR 600 1639 01:14:46,120 --> 01:14:47,240 MILLION YEARS THEN WENT SOUTH 1640 01:14:47,240 --> 01:14:53,200 BUT RATHER THAN BECAUSE MOST OF 1641 01:14:53,200 --> 01:14:58,320 THE WAY YOU GET WET WARM 1642 01:14:58,320 --> 01:15:00,760 ENVIRONMENTS ON MARS IS THROUGH 1643 01:15:00,760 --> 01:15:03,560 LARGE METEOR IMPACTS OR LARGE 1644 01:15:03,560 --> 01:15:06,520 VOLCANIC EVENTS SO WE THINK MARS 1645 01:15:06,520 --> 01:15:08,480 WAS WARM AN WET FOR MAYBE 1646 01:15:08,480 --> 01:15:10,800 100,000 YEARS, EVERY TEN MILLION 1647 01:15:10,800 --> 01:15:15,080 YEARS ACCORDING FOR THE FIRST 1648 01:15:15,080 --> 01:15:15,960 600 YEARS OF MARTIAN HISTORY. 1649 01:15:15,960 --> 01:15:18,160 THAT IS A MUCH LESS INVITING 1650 01:15:18,160 --> 01:15:19,680 SCENARIO FOR BIOLOGY. DOESN'T 1651 01:15:19,680 --> 01:15:24,000 RULE IT OUT BUT I THINK RIGHT 1652 01:15:24,000 --> 01:15:27,040 NOW WE ARE -- I'M STILL LOOKING 1653 01:15:27,040 --> 01:15:29,000 FOR EVIDENCE THAT WOULD MAKE ME 1654 01:15:29,000 --> 01:15:34,800 WANT TO BUY MORE STOCK IN MARS 1655 01:15:34,800 --> 01:15:37,480 BIOLOGY. 1656 01:15:37,480 --> 01:15:43,440 >> ONE OF THE PLAYERS IN THIS 1657 01:15:43,440 --> 01:15:45,360 DISCUSSION THAT HASN'T BEEN 1658 01:15:45,360 --> 01:15:49,960 MENTIONED, REALLY ASKS HOW DO 1659 01:15:49,960 --> 01:15:53,440 VIRUSES FIT INTO THIS 1660 01:15:53,440 --> 01:15:54,640 DISCUSSION? ARE WE MISSING 1661 01:15:54,640 --> 01:16:01,640 SOMETHING? WE CAN EFFECTS OF 1662 01:16:01,640 --> 01:16:03,000 BACTERIA OR VIRUSES OR BY 1663 01:16:03,000 --> 01:16:04,760 SOMETHING ELSE? WHAT ARE YOUR 1664 01:16:04,760 --> 01:16:05,680 COMMENTS ABOUT THAT? 1665 01:16:05,680 --> 01:16:10,560 >> NO, AGAIN, A GREAT QUESTION. 1666 01:16:10,560 --> 01:16:15,320 JUST AS ENVIRONMENTAL SEQUENCING 1667 01:16:15,320 --> 01:16:17,880 TAUGHT US WE WERE SUBSTANTIAL 1668 01:16:17,880 --> 01:16:21,080 IGNORANCE ABOUT THE DIVERSITY OF 1669 01:16:21,080 --> 01:16:22,600 BACTERIA THE LAST FEW DECADES 1670 01:16:22,600 --> 01:16:25,480 THERE IS MORE AND MORE 1671 01:16:25,480 --> 01:16:27,400 SEQUENCING OF VIRUSES, THERE 1672 01:16:27,400 --> 01:16:28,760 SOMETHING CALLED THE TARA 1673 01:16:28,760 --> 01:16:30,600 PROJECT RUN OUT OF FRANCE MOSTLY 1674 01:16:30,600 --> 01:16:32,360 WHICH HAS JUST TRANSFORMED OUR 1675 01:16:32,360 --> 01:16:35,200 UNDERSTANDING OF BIOLOGIC 1676 01:16:35,200 --> 01:16:36,440 DIVERSITY AND SURFACE OCEANS. 1677 01:16:36,440 --> 01:16:40,880 THEY FOUND SOMETHING LIKE 1678 01:16:40,880 --> 01:16:42,480 250,000 DISTINCT RNA VIRUSES 1679 01:16:42,480 --> 01:16:44,680 JUST TO THE UP PER HUNDRED 1680 01:16:44,680 --> 01:16:49,920 METERS OF THE OCEANS.S SO AGAIN 1681 01:16:49,920 --> 01:16:52,440 SUGGESTING THAT VIRUSES ARE 1682 01:16:52,440 --> 01:16:54,920 EVERYWHERE, I REMEMBER ONE 1683 01:16:54,920 --> 01:16:57,840 PERSON ESTIMATED SOMETHING LIKE 1684 01:16:57,840 --> 01:16:59,160 97% OF GENES IN THE OCEAN ARE 1685 01:16:59,160 --> 01:17:06,880 VIRAL. SO IN TERMS OF THE 1686 01:17:06,880 --> 01:17:10,240 ECOLOGY OF VIRUSES WE ARE JUST 1687 01:17:10,240 --> 01:17:13,000 STARTING TO LEARN ALL THINGS 1688 01:17:13,000 --> 01:17:16,440 THEY DO. AS SOME OF YOU MAY 1689 01:17:16,440 --> 01:17:18,880 KNOW, IN SCHOOL WE ALWAYS LEARN 1690 01:17:18,880 --> 01:17:22,360 VIRUSES HAVE THESE VERY SMALL 1691 01:17:22,360 --> 01:17:23,520 GENOMES BECAUSE THOSE VIRUSES 1692 01:17:23,520 --> 01:17:25,720 THAT WE KNOW ABOUT FROM DISEASES 1693 01:17:25,720 --> 01:17:27,720 TEND TO BE THAT WAY. BUT THERE 1694 01:17:27,720 --> 01:17:29,360 ARE VIRUSES THAT HAVE BEEN FOUND 1695 01:17:29,360 --> 01:17:31,760 IN THE LAST DECADE THAT HAVE 1696 01:17:31,760 --> 01:17:33,720 GENOMES LARGER THAN SMALL 1697 01:17:33,720 --> 01:17:37,360 BACTERIA. THERE ARE ONES THAT 1698 01:17:37,360 --> 01:17:41,640 HAVE EXAMPLE, THE ENTIRE GENE 1699 01:17:41,640 --> 01:17:44,240 CASSETTE FOR SYNTHETIC ELECTRON 1700 01:17:44,240 --> 01:17:47,040 TRANSFER, IT IS THOUGHT THESE 1701 01:17:47,040 --> 01:17:51,320 MAY HAVE THESE ESSENTIALLY TO 1702 01:17:51,320 --> 01:17:52,920 INCREASE METABOLIC PRODUCTIVITY 1703 01:17:52,920 --> 01:17:55,280 OF THEIR HOST. SO THEY CAN 1704 01:17:55,280 --> 01:17:57,720 ACTUALLY INCREASE THEIR OWN 1705 01:17:57,720 --> 01:18:01,080 NUMBERS FOR DISSEMINATION. WE 1706 01:18:01,080 --> 01:18:02,920 ARE ALSO FINDING VIRUSES ARE 1707 01:18:02,920 --> 01:18:07,720 VERY IMPORTANT IN THE ECOLOGY OF 1708 01:18:07,720 --> 01:18:10,600 PLANTS AND ANIMALS AND PROTUS IN 1709 01:18:10,600 --> 01:18:13,240 WAYS WE DON'T REALLY HELP SHAPE 1710 01:18:13,240 --> 01:18:15,240 ECOSYSTEM. SO IN TERMS OF JUST 1711 01:18:15,240 --> 01:18:18,480 DIVERSITY AND ECOLOGY, WE ARE 1712 01:18:18,480 --> 01:18:22,800 JUST ENTERING THIS WONDERFUL 1713 01:18:22,800 --> 01:18:25,160 EXCITING NEW WORLD UNDERSTANDING 1714 01:18:25,160 --> 01:18:28,400 WHAT VIRUSES DO AND NOT JUST THE 1715 01:18:28,400 --> 01:18:32,040 SMALL NUMBER OF VIRUSES THAT 1716 01:18:32,040 --> 01:18:37,360 HAVE INVOLVED IN DISEASE BUT 1717 01:18:37,360 --> 01:18:38,720 ASTOUNDINGLY GREATER DIVERSITY 1718 01:18:38,720 --> 01:18:41,520 OF VIRUSES THAT ARE INVOLVED IN 1719 01:18:41,520 --> 01:18:42,360 FUNCTIONING OF NATURAL ECO 1720 01:18:42,360 --> 01:18:47,040 SYSTEMS. THE OTHER PART OF THE 1721 01:18:47,040 --> 01:18:48,280 QUESTION, DO THEY FIT INTO THE 1722 01:18:48,280 --> 01:18:51,720 ORIGIN OF LIFE? I THINK YOU CAN 1723 01:18:51,720 --> 01:18:53,480 FIND PEOPLE WHO ARGUE THIS IN 1724 01:18:53,480 --> 01:18:58,120 DIFFERENT WAYS. IT IS CLEAR THAT 1725 01:18:58,120 --> 01:19:02,480 AT LEAST SOME VIRUSES ARE 1726 01:19:02,480 --> 01:19:03,800 RENEGADE GENES THAT ORIGINATED 1727 01:19:03,800 --> 01:19:08,280 IN ORGANISMS AND HAVE 1728 01:19:08,280 --> 01:19:11,600 ESSENTIALLY GONE OFF ON THEIR 1729 01:19:11,600 --> 01:19:15,720 OWN. THAT SAID I THINK PEOPLE 1730 01:19:15,720 --> 01:19:18,280 THAT HAD YOU BEEN AROUND A 1731 01:19:18,280 --> 01:19:19,720 BILLION YEARS AGO YOU WOULD HAVE 1732 01:19:19,720 --> 01:19:22,200 SEEN A LOT OF VIRUSES OR 1733 01:19:22,200 --> 01:19:24,360 INSIPIENT VIRUSES SO I THINK 1734 01:19:24,360 --> 01:19:26,280 THEY HAVE ALWAYS BEEN WITH US 1735 01:19:26,280 --> 01:19:29,920 BUT BY DEFINITION A VIRUS IS 1736 01:19:29,920 --> 01:19:35,040 DEPENDENT ON HOST CELL. FOR ITS 1737 01:19:35,040 --> 01:19:37,960 REPLICATION. SO IT IS HARD TO 1738 01:19:37,960 --> 01:19:39,440 THINK VIRUSES WERE CENTRAL TO 1739 01:19:39,440 --> 01:19:41,880 THE ORIGIN OF LIFE, COULD BE 1740 01:19:41,880 --> 01:19:43,960 WRONG ABOUT THAT. BUT I THINK 1741 01:19:43,960 --> 01:19:45,960 THEY HAVE PROBABLY FOR FOUR 1742 01:19:45,960 --> 01:19:50,000 BILLION YEARS BEEN IMPORTANT TO 1743 01:19:50,000 --> 01:19:52,200 THE EVOLUTION AND ECOLOGY OF 1744 01:19:52,200 --> 01:19:52,520 LIFE. 1745 01:19:52,520 --> 01:19:56,240 >> YOUR COMMENTS ALSO PERTAIN TO 1746 01:19:56,240 --> 01:20:05,000 SOMETHING LIKE BACTERIA PHAGO? 1747 01:20:05,000 --> 01:20:07,320 >> MY GUESS IS EVERY ORGANISM IS 1748 01:20:07,320 --> 01:20:09,320 ASSOCIATED WITH MUCH LARGER 1749 01:20:09,320 --> 01:20:12,520 DIVERSITY OF VIRUSES THAN WE 1750 01:20:12,520 --> 01:20:14,760 HAVE BEEN ABLE TO WORK OUT 1751 01:20:14,760 --> 01:20:17,600 THROUGH THE TRADITIONAL WAYS 1752 01:20:17,600 --> 01:20:21,640 THAT WE HAVE WORK WITH VIRUSES. 1753 01:20:21,640 --> 01:20:24,080 I DO HAVE SOME CONFIDENCE THAT 1754 01:20:24,080 --> 01:20:28,360 WHEN YOU GET A PHYSICAL 10 OR 15 1755 01:20:28,360 --> 01:20:29,840 YEARS FROM NOW THEY WILL TAKE A 1756 01:20:29,840 --> 01:20:33,000 STOOL SAMPLE AND LOOK AT YOUR 1757 01:20:33,000 --> 01:20:34,480 MICROBIOTA AND THAT WILL TELL 1758 01:20:34,480 --> 01:20:38,040 YOU MORE ABOUT THE STATE OF YOUR 1759 01:20:38,040 --> 01:20:39,880 HEALTH THAN THE PHYSICALS DUE 1760 01:20:39,880 --> 01:20:40,840 TODAY. WHETHER OR NOT WE WILL 1761 01:20:40,840 --> 01:20:43,440 KNOW ENOUGH ABOUT VIRUSES TO 1762 01:20:43,440 --> 01:20:46,440 INCORPORATE THEM INTO THAT KIND 1763 01:20:46,440 --> 01:20:53,720 OF PRACTICE, I DON'T KNOW. 1764 01:20:53,720 --> 01:20:59,560 >> ANDREW ASKS, OTHER THAN 1765 01:20:59,560 --> 01:21:00,400 PATHOGENICITY, WHAT DO YOU FEEL 1766 01:21:00,400 --> 01:21:03,200 IS THE STRONGEST SELECTIVE 1767 01:21:03,200 --> 01:21:06,000 PRESSURE THAT MICROBES EXERT ON 1768 01:21:06,000 --> 01:21:11,360 MULTI-CELLULAR LIFE? 1769 01:21:11,360 --> 01:21:14,200 >> THAT IS A GOOD QUESTION. I 1770 01:21:14,200 --> 01:21:16,920 THINK THEY EXERT A NUMBER OF 1771 01:21:16,920 --> 01:21:21,320 DIFFERENT TYPES. IN SOME WAYS 1772 01:21:21,320 --> 01:21:22,960 THEY USE ENVIRONMENTAL PRESSURES 1773 01:21:22,960 --> 01:21:25,560 BY DIFFERENT MICROBIAL 1774 01:21:25,560 --> 01:21:29,520 METABOLISMS. COMPETING FOR 1775 01:21:29,520 --> 01:21:32,480 NUTRIENTS. AGAIN THERE IS 1776 01:21:32,480 --> 01:21:33,520 PROBABLY PEOPLE IN THE AUDIENCE 1777 01:21:33,520 --> 01:21:34,960 MUCH MORE EXPERIMENTAL IN THIS 1778 01:21:34,960 --> 01:21:39,920 THAN I AM, BUT MY UNDERSTANDING 1779 01:21:39,920 --> 01:21:45,840 IS THE DEVELOPMENT OF YOUR 1780 01:21:45,840 --> 01:21:48,800 ADJUSTOR SYSTEM IS IN PART 1781 01:21:48,800 --> 01:21:52,120 GUIDED BY BACTERIA. BACTERIA 1782 01:21:52,120 --> 01:21:55,360 PLAY AN IMPORTANT ROLE IN THE 1783 01:21:55,360 --> 01:21:59,320 BREAK DOWN OF FOOD FOR 1784 01:21:59,320 --> 01:22:01,600 METABOLISM. I'M TOLD BACTERIA 1785 01:22:01,600 --> 01:22:02,720 ACTUALLY HELP TO TRAIN THE 1786 01:22:02,720 --> 01:22:08,800 IMMUNE SYSTEM. SO IN ESSENCE IF 1787 01:22:08,800 --> 01:22:10,920 THAT IS CORRECT, I THINK WILL 1788 01:22:10,920 --> 01:22:12,440 REASON TO BELIEVE THAT IT 1789 01:22:12,440 --> 01:22:17,320 SOMEHOW IS, BACTERIA PLAY AN 1790 01:22:17,320 --> 01:22:19,920 IMPORTANT ROLE IN JUST NORMAL 1791 01:22:19,920 --> 01:22:21,720 DEVELOPMENT AND FUNCTIONING OF 1792 01:22:21,720 --> 01:22:24,440 THE HUMAN ORGANISM. I THINK IT 1793 01:22:24,440 --> 01:22:27,360 IS VERY LIKELY THAT AS WE LEARN 1794 01:22:27,360 --> 01:22:30,480 MORE ABOUT THESE WE ARE FINDING 1795 01:22:30,480 --> 01:22:32,200 THAT THEY PLAY, MANY MORE 1796 01:22:32,200 --> 01:22:35,360 BACTERIA THAT PLAY THAT KIND OF 1797 01:22:35,360 --> 01:22:38,320 CONSTITUTIVE ROLE IN OUR HEALTH 1798 01:22:38,320 --> 01:22:39,120 AND THERE THERE ARE THAT PLAY A 1799 01:22:39,120 --> 01:22:43,800 ROLE IN PATHOGENICITY. 1800 01:22:43,800 --> 01:22:46,360 >> THE STUDIES OF THE TYPE THAT 1801 01:22:46,360 --> 01:22:53,480 YOU ARE DESCRIBING PROVIDE 1802 01:22:53,480 --> 01:23:01,240 INFORMATION ABOUT HOW THE 1803 01:23:01,240 --> 01:23:02,200 POSTULATED SPLIT BETWEEN 1804 01:23:02,200 --> 01:23:06,160 BACTERIA AND ARCHAEA TOOK PLACE? 1805 01:23:06,160 --> 01:23:08,240 >> ANOTHER GOOD QUESTION. I 1806 01:23:08,240 --> 01:23:09,960 DON'T THINK WE KNOW MUCH ABOUT 1807 01:23:09,960 --> 01:23:13,200 THAT TO BE HONEST. THERE ARE -- 1808 01:23:13,200 --> 01:23:15,520 IF YOU JUST LOOK AT THE 1809 01:23:15,520 --> 01:23:17,040 MOLECULAR CHARACTERISTICS OF 1810 01:23:17,040 --> 01:23:20,560 BACTERIA AND ARCHEA, THERE ARE 1811 01:23:20,560 --> 01:23:22,680 OBVIOUSLY NUMBER OF THINGS THAT 1812 01:23:22,680 --> 01:23:26,720 GO BACK TO A COMMON ANCESTOR. 1813 01:23:26,720 --> 01:23:29,200 THINGS AS STRAIGHT FORWARD AS 1814 01:23:29,200 --> 01:23:34,680 CONTENT OF MEMBRANES, ARE 1815 01:23:34,680 --> 01:23:37,240 DISTINCT. UNFORTUNATELY WE HAVE 1816 01:23:37,240 --> 01:23:43,440 NO ORGANISMS THAT PRE-DATE THAT 1817 01:23:43,440 --> 01:23:45,680 DIVERGENCE BETWEEN THE TWO SO WE 1818 01:23:45,680 --> 01:23:47,760 CAN ONLY MAKE VERY BROAD 1819 01:23:47,760 --> 01:23:48,760 INFERENCES ABOUT WHETHER A 1820 01:23:48,760 --> 01:23:50,640 COMMON ANCESTOR WOULD HAVE 1821 01:23:50,640 --> 01:23:55,840 LOOKED LIKE. THERE ARE SOME 1822 01:23:55,840 --> 01:23:57,720 ECOLOGICAL DIFFERENCES THAT 1823 01:23:57,720 --> 01:23:58,800 MIGHT BE INFORMATIVE IN SOME 1824 01:23:58,800 --> 01:24:06,080 WAY. IT HAS BEEN SUGGESTED THAT 1825 01:24:06,080 --> 01:24:07,360 ARCHAEA ARE PARTICULARLY 1826 01:24:07,360 --> 01:24:08,120 SUCCESSFUL IN LOW ENERGY 1827 01:24:08,120 --> 01:24:11,840 ENVIRONMENTS. THEY ARE ABLE TO 1828 01:24:11,840 --> 01:24:14,080 SCAVENGE ENERGY EFFICIENTLY AND 1829 01:24:14,080 --> 01:24:18,360 MAINTAIN THEIR BIOLOGY WITH LOW 1830 01:24:18,360 --> 01:24:20,560 FLUXES OF ENERGY, MANY OF THEM 1831 01:24:20,560 --> 01:24:27,280 ARE. SO IT MAY BE THAT EARLY ON 1832 01:24:27,280 --> 01:24:29,080 TWO DIFFERENT GROUPS OF 1833 01:24:29,080 --> 01:24:30,920 ORGANISMS BECAME SUCCESSFUL AT 1834 01:24:30,920 --> 01:24:34,360 COLONIZING DISTINCTLY DIFFERENT 1835 01:24:34,360 --> 01:24:39,560 ENVIRONMENTS. THAT SAID, I DON'T 1836 01:24:39,560 --> 01:24:41,760 THINK WE KNOW A GREAT DEAL ABOUT 1837 01:24:41,760 --> 01:24:42,960 DIVERGENCE, THAT IS AN IMPORTANT 1838 01:24:42,960 --> 01:24:52,200 QUESTION. EVERY COUPLE OF YEARS, 1839 01:24:52,200 --> 01:24:58,800 I GO BACK AND REFURBISH MY 1840 01:24:58,800 --> 01:25:00,080 SLIDES ON PHYLOGENY AN EVERY 1841 01:25:00,080 --> 01:25:03,080 TIME THERE IS WHOLE MAJOR GROUPS 1842 01:25:03,080 --> 01:25:13,640 OF ARCHAEA. ASGARD ARCHEAA META 1843 01:25:15,600 --> 01:25:17,760 GENOMIC SEQUENCES IN 2015, 1844 01:25:17,760 --> 01:25:18,840 THERE'S AT LEAST TWO IN CULTURE 1845 01:25:18,840 --> 01:25:21,800 THESE ARE REALLY COOL. THEY 1846 01:25:21,800 --> 01:25:26,400 HAVE A NUMBER OF MOLECULAR 1847 01:25:26,400 --> 01:25:28,560 CHARACTERISTICS THAT 20 YEARS 1848 01:25:28,560 --> 01:25:30,400 AGO WE WOULD HAVE SAID WERE 1849 01:25:30,400 --> 01:25:32,000 UNIQUE TO EUKARYOTS AND SEEMED 1850 01:25:32,000 --> 01:25:34,440 TO BE PLAYING A ROLE IN THE 1851 01:25:34,440 --> 01:25:35,960 EMERGENCE OF EUKARYOTS. SO ONE 1852 01:25:35,960 --> 01:25:39,880 OF THE LESSONS THEY TAKE FROM 1853 01:25:39,880 --> 01:25:43,360 THAT IS THAT PARTICULARLY FOR 1854 01:25:43,360 --> 01:25:45,320 ARCHAEA AND ALSO BACTERIA, WILL 1855 01:25:45,320 --> 01:25:47,000 IS AN AWFUL LOT ABOUT THEIR 1856 01:25:47,000 --> 01:25:50,480 DIVERSITY THAN WE JUST DON'T YET 1857 01:25:50,480 --> 01:25:52,160 UNDERSTAND. IT IS POSSIBLE THAT 1858 01:25:52,160 --> 01:25:55,400 AS WE LEARN MORE ABOUT NATURAL 1859 01:25:55,400 --> 01:25:57,240 HISTORY OF BOTH GROUPS Z THAT 1860 01:25:57,240 --> 01:25:59,720 WILL SHED SOME LIGHT ON THE 1861 01:25:59,720 --> 01:26:01,640 QUESTION THAT WAS ASKED. FOR 1862 01:26:01,640 --> 01:26:03,120 NOW, I THINK WE ARE IN 1863 01:26:03,120 --> 01:26:10,400 SUBSTANTIAL IGNORANCE. 1864 01:26:10,400 --> 01:26:14,320 >> WHERE DO YOU THINK LIFE 1865 01:26:14,320 --> 01:26:16,920 STARTED? THERE SEEMS TO BE SORT 1866 01:26:16,920 --> 01:26:21,840 OF A GEOTHERMAL SCHOOL AND A 1867 01:26:21,840 --> 01:26:24,560 DEEP SEA VENT SCHOOL. IS THERE 1868 01:26:24,560 --> 01:26:27,560 COMPELLING EVIDENCE IN YOUR VIEW 1869 01:26:27,560 --> 01:26:30,280 FOR THESE OR ARE THEY STILL 1870 01:26:30,280 --> 01:26:32,600 LARGELY HYPOTHETICAL? AND WHAT 1871 01:26:32,600 --> 01:26:34,480 IS YOUR VIEW OF THAT? 1872 01:26:34,480 --> 01:26:39,600 >> AGAIN, IT IS A GOOD QUESTION, 1873 01:26:39,600 --> 01:26:43,440 WE KNOW THERE ARE CERTAIN TYPES 1874 01:26:43,440 --> 01:26:45,560 OF ENVIRONMENTS ASSOCIATED WITH 1875 01:26:45,560 --> 01:26:48,200 HYDRO THERMAL VENTS. WHERE IF 1876 01:26:48,200 --> 01:26:51,960 YOU CAN FIGURE OUT A WAY TO MAKE 1877 01:26:51,960 --> 01:26:55,520 A MEMBRANE LIKE SUBSTANCE YOU 1878 01:26:55,520 --> 01:26:58,040 WOULD GET A PH DIFFERENCE ON THE 1879 01:26:58,040 --> 01:27:00,840 TWO SIDES OF THAT THAT ALLOW YOU 1880 01:27:00,840 --> 01:27:02,960 TO BASICALLY TRANSPORT ELECTRONS 1881 01:27:02,960 --> 01:27:05,600 WHICH IS IN SOME WAYS AT THE 1882 01:27:05,600 --> 01:27:08,080 HEART OF ENERGY METABOLISM. WE 1883 01:27:08,080 --> 01:27:11,800 KNOW ALSO FROM EXPERIMENTAL 1884 01:27:11,800 --> 01:27:14,280 EVIDENCE IN SIMULATED 1885 01:27:14,280 --> 01:27:18,240 ENVIRONMENTS LIKE HYDRO THERMAL 1886 01:27:18,240 --> 01:27:21,160 VENTS, YOU CAN SYNTHESIZE AS I 1887 01:27:21,160 --> 01:27:22,680 MENTION SOME INTERMEDIATES IN 1888 01:27:22,680 --> 01:27:26,240 THE KREBS CYCLE. ON THE OTHER 1889 01:27:26,240 --> 01:27:31,400 HAND, THESE HOT ENVIRONMENTS 1890 01:27:31,400 --> 01:27:33,520 TEND TO BE PLACES WHERE 1891 01:27:33,520 --> 01:27:34,960 MOLECULES BREAK DOWN. THEY DON'T 1892 01:27:34,960 --> 01:27:35,880 HAVE LONG HALF LIVES. 1893 01:27:35,880 --> 01:27:39,480 THE ALTERNATIVE, WHICH IS I 1894 01:27:39,480 --> 01:27:41,480 THINK NOW MUCH DISCUSSED BY 1895 01:27:41,480 --> 01:27:43,960 PEOPLE LIKE JOHN SOUTHER LAND 1896 01:27:43,960 --> 01:27:49,640 FROM CAMBRIDGE AND OTHERS, IS 1897 01:27:49,640 --> 01:27:51,160 LAKES. BECAUSE LAKES HAVE THIS 1898 01:27:51,160 --> 01:27:52,560 INTERESTING CHARACTERISTIC OF 1899 01:27:52,560 --> 01:27:54,360 DRYING UP AND WETTING AGAIN SO 1900 01:27:54,360 --> 01:27:56,520 YOU CAN ACTUALLY DRIVE SOME 1901 01:27:56,520 --> 01:27:58,600 INTERESTING CHEMISTRY BY THAT 1902 01:27:58,600 --> 01:28:06,160 KIND OF CYCLING. LAKES AT LEAST 1903 01:28:06,160 --> 01:28:07,880 MINIMIZE PROBLEM OF DILUTION 1904 01:28:07,880 --> 01:28:11,560 WHICH IS A BIG PROBLEM IN THE 1905 01:28:11,560 --> 01:28:13,360 OCEANS. AGAIN, THERE ARE 1906 01:28:13,360 --> 01:28:16,440 CERTAIN TYPES OF CHEMISTRY 1907 01:28:16,440 --> 01:28:20,360 INCLUDING SOME OF THE RNA. 1908 01:28:20,360 --> 01:28:21,760 CHEMISTRY THAT HAS BEEN DONE IN 1909 01:28:21,760 --> 01:28:23,560 THE LABORATORY THAT MAKE SENSE 1910 01:28:23,560 --> 01:28:26,760 IN TERMS OF LAKE ENVIRONMENTS. 1911 01:28:26,760 --> 01:28:28,120 SO THERE ARE SOME ADVANTAGES TO 1912 01:28:28,120 --> 01:28:31,520 BOTH OF THESE. AND WHAT I FIND 1913 01:28:31,520 --> 01:28:34,800 INTERESTING THE GEOLOGISTS IN ME 1914 01:28:34,800 --> 01:28:37,200 IS THESE TWO GROUPS COME AFTER 1915 01:28:37,200 --> 01:28:38,920 EACH OTHER WITH HAMMERS AND 1916 01:28:38,920 --> 01:28:41,080 TONGS AND NONE OF THEM EVER STOP 1917 01:28:41,080 --> 01:28:43,320 TO THINK IF THEY GO TO ICELAND 1918 01:28:43,320 --> 01:28:45,520 THEY WOULD FIND WHERE THE MID 1919 01:28:45,520 --> 01:28:47,040 ATLANTIC RIDGE HYDRO THERMAL 1920 01:28:47,040 --> 01:28:49,440 RIDGE COMES UP ABOVE SEA LEVEL 1921 01:28:49,440 --> 01:28:52,200 AND IS COVERED BY LAKES. SO I 1922 01:28:52,200 --> 01:28:55,920 THINK IN THE REAL WORLD, THESE 1923 01:28:55,920 --> 01:28:59,680 ARE NOT MUTUALLY EXCLUSIVE 1924 01:28:59,680 --> 01:29:03,960 HYPOTHESES THAT THEIR PRO POINTS 1925 01:29:03,960 --> 01:29:06,240 MAKE THEM OUT -- PROPONENTS MAKE 1926 01:29:06,240 --> 01:29:06,920 THEM OUT TO BE. 1927 01:29:06,920 --> 01:29:09,000 >> APROPOS OF DISCUSSION OF 1928 01:29:09,000 --> 01:29:10,760 VIRUS WE HAVE A QUESTION FROM 1929 01:29:10,760 --> 01:29:12,720 BOB WHO ASKS WHETHER VIRUSES 1930 01:29:12,720 --> 01:29:17,360 MEET YOUR DEFINITION OF LIFE. A 1931 01:29:17,360 --> 01:29:19,000 CHEMICAL UNSUSTAINING SYSTEM 1932 01:29:19,000 --> 01:29:21,920 CAPABLE OF DARWINIAN EVOLUTION. 1933 01:29:21,920 --> 01:29:24,240 >> WELL, THEY COME CLOSE. I KNOW 1934 01:29:24,240 --> 01:29:26,600 A LOT OF PEOPLE DON'T LIKE TO 1935 01:29:26,600 --> 01:29:30,000 THINK OF THEM AS LIFE BECAUSE 1936 01:29:30,000 --> 01:29:32,920 THEY DON'T METABOLIZE, THEY 1937 01:29:32,920 --> 01:29:36,080 DON'T DO ALL SORTS OF THINGS 1938 01:29:36,080 --> 01:29:38,320 MOST LIFE DOES. THEY ARE CLEARLY 1939 01:29:38,320 --> 01:29:42,080 SUBJECT TO DARWINIAN EVOLUTION. 1940 01:29:42,080 --> 01:29:45,080 IN THAT -- THAT IS A VOTE FOR 1941 01:29:45,080 --> 01:29:47,000 LIFE. THEY ARE NOT 1942 01:29:47,000 --> 01:29:51,800 SELF-SUSTAINING. WHICH I GUESS A 1943 01:29:51,800 --> 01:29:55,160 VOTE AGAINST IT. . I DON'T GET 1944 01:29:55,160 --> 01:30:00,000 TERRIBLY EXCITED ABOUT THE 1945 01:30:00,000 --> 01:30:03,000 DEBATE OF WHETHER VIRUSES ARE OR 1946 01:30:03,000 --> 01:30:05,240 ARE NOT LIVING BECAUSE THEY 1947 01:30:05,240 --> 01:30:07,080 CERTAINLY ARE INTIMATELY 1948 01:30:07,080 --> 01:30:09,520 CONNECTED TO LIFE IN TERMS OF 1949 01:30:09,520 --> 01:30:17,760 BOTH FUNCTION AND EVOLUTION. 1950 01:30:17,760 --> 01:30:21,160 >> SOMEWHAT RELATED TO THAT, 1951 01:30:21,160 --> 01:30:24,560 TARIN ASKS IS THERE ANY EVIDENCE 1952 01:30:24,560 --> 01:30:27,600 FOR UNIQUE BIOMOLECULES FOR 1953 01:30:27,600 --> 01:30:31,560 EXAMPLE DNA, RNA, SOMETHING LIKE 1954 01:30:31,560 --> 01:30:34,640 THAT, HYBRID, OR PROTEINS, DO WE 1955 01:30:34,640 --> 01:30:37,400 HAVE ANY EVIDENCE OF THE 1956 01:30:37,400 --> 01:30:39,560 BIOMOLECULES THAT ARE MADE 1957 01:30:39,560 --> 01:30:41,360 DURING THE EARLY TIME PERIODS OF 1958 01:30:41,360 --> 01:30:45,320 LIFE HISTORY? IS THERE ANY 1959 01:30:45,320 --> 01:30:47,760 TECHNOLOGY THAT PERMITS SOME 1960 01:30:47,760 --> 01:30:49,040 UNDERSTANDING OF WHAT THOSE 1961 01:30:49,040 --> 01:30:52,320 MOLECULES ARE? 1962 01:30:52,320 --> 01:30:57,880 >> NO. ONE OF THE ISSUES OF THE 1963 01:30:57,880 --> 01:31:00,480 GEOLOGIC RECORD IS THAT 1964 01:31:00,480 --> 01:31:01,960 SEDIMENTARY ROCKS DEPOSITED 1965 01:31:01,960 --> 01:31:04,920 THROUGH TIME CREATE AND PRESERVE 1966 01:31:04,920 --> 01:31:06,760 A RECORD OF LIFE AND 1967 01:31:06,760 --> 01:31:08,880 ENVIRONMENTS WHEN AND WHERE THEY 1968 01:31:08,880 --> 01:31:16,640 FORM. BUT EROSION IS AN ERASER. 1969 01:31:16,640 --> 01:31:19,600 ONCE YOU GET BACK 4, 3 1/2 1970 01:31:19,600 --> 01:31:23,040 MILLION YEARS AGO THERE IS VERY 1971 01:31:23,040 --> 01:31:24,280 LITTLE RECORD OF SEDIMENTARY 1972 01:31:24,280 --> 01:31:28,200 ROCKS. THE OLDEST AREKS THAT WE 1973 01:31:28,200 --> 01:31:30,800 KNOW OF -- OLDEST ROCKS ARE 1974 01:31:30,800 --> 01:31:34,160 HIGHLY ME THATMORPHOSIS A 1975 01:31:34,160 --> 01:31:35,000 MILLION YEARS OLDS. WE HAVE 1976 01:31:35,000 --> 01:31:37,920 OLDER MINERALS ONE CALLED 1977 01:31:37,920 --> 01:31:40,680 ZIRCON, THE GEOLOGIST FRIEND 1978 01:31:40,680 --> 01:31:44,880 BECAUSE ZIRCON'S -- IT IS -- 1979 01:31:44,880 --> 01:31:48,840 THERE IS ZIRCONIUM SILICATED. 1980 01:31:48,840 --> 01:31:51,160 THEY ACTUALLY INCORPORATE 1981 01:31:51,160 --> 01:31:53,120 URANIUM INTO CRYSTAL LATTICES 1982 01:31:53,120 --> 01:31:57,360 BUT DON'T INCORPORATE LEAD. 1983 01:31:57,360 --> 01:31:59,600 SOME OF THAT URANIUM IS RADIO 1984 01:31:59,600 --> 01:32:02,920 ACTIVE AND GIVES RISE TO RADIO 1985 01:32:02,920 --> 01:32:05,040 GENIC LEAD WHICH STAYS IN THE 1986 01:32:05,040 --> 01:32:07,960 CRYSTAL LATTICE. SO THOSE ARE 1987 01:32:07,960 --> 01:32:10,680 ACTUALLY THE BEST MATERIALS FOR 1988 01:32:10,680 --> 01:32:14,480 RADIO METRIC DATING. 1989 01:32:14,480 --> 01:32:16,360 INTERESTINGLY ENOUGH IF YOU GO 1990 01:32:16,360 --> 01:32:18,840 TO THE NORTHS SHORE OF BOSTON 1991 01:32:18,840 --> 01:32:21,360 TODAY AN COLLECT A BUCKET FULL 1992 01:32:21,360 --> 01:32:25,000 OF SAND, THERE WILL BE A NUMBER 1993 01:32:25,000 --> 01:32:27,200 OF ZIRCON CRYSTALS THERE THAT 1994 01:32:27,200 --> 01:32:29,120 FORMED IN GRANITES THAT MADE THE 1995 01:32:29,120 --> 01:32:30,600 WHITE MOUNTAINS IN NEW HAMPSHIRE 1996 01:32:30,600 --> 01:32:33,920 AND TRANSPORTED DOWN TO THE 1997 01:32:33,920 --> 01:32:37,200 SEASHORE BY EROSION. AND ARE 1998 01:32:37,200 --> 01:32:40,040 JUST NOW -- THEY ARE 400 1999 01:32:40,040 --> 01:32:42,200 MILLION-YEAR-OLD ZIRCONS SITTING 2000 01:32:42,200 --> 01:32:43,040 IN P MODERNIZED. 2001 01:32:43,040 --> 01:32:47,040 S. WE DO HAVE EXAMPLES OF 2002 01:32:47,040 --> 01:32:48,560 ZIRCONS MORE THAN 4 BILLION 2003 01:32:48,560 --> 01:32:55,000 YEARS OLD THAT ARE IN 2004 01:32:55,000 --> 01:32:55,840 3.6 BILLION-YEAR-OLD SAND STONES 2005 01:32:55,840 --> 01:32:59,120 SO WE GET CLUES TO THE EARLY 2006 01:32:59,120 --> 01:33:02,240 EARTH BUT NOTHING TO PRESERVE 2007 01:33:02,240 --> 01:33:05,480 THE TYPE OF MOLECULES THAT ARE 2008 01:33:05,480 --> 01:33:10,680 BEING ASKED ABOUT. SO ALL OUR 2009 01:33:10,680 --> 01:33:16,040 INFERENCES ABOUT THE TYPES OF 2010 01:33:16,040 --> 01:33:17,800 MOLECULES THAT COULD HAVE BEEN 2011 01:33:17,800 --> 01:33:20,360 AND PROBABLY WERE MADE BY A 2012 01:33:20,360 --> 01:33:21,480 BIOLOGICAL PROCESSES COME FROM 2013 01:33:21,480 --> 01:33:23,840 ONE OF TWO SOURCES. ONE, 2014 01:33:23,840 --> 01:33:26,640 EXPERIMENTS. EVER SINCE MILLER 2015 01:33:26,640 --> 01:33:29,640 AND URI THERE'S BEEN COTTAGE 2016 01:33:29,640 --> 01:33:34,160 INDUSTRY OF PEOPLE DOING 2017 01:33:34,160 --> 01:33:34,960 PREBIOTIC CHEMISTRY. THAT HAS 2018 01:33:34,960 --> 01:33:36,680 BEEN VERY SUCCESSFUL IN SOME 2019 01:33:36,680 --> 01:33:40,640 WAYS IN SHOWING THAT WE CAN 2020 01:33:40,640 --> 01:33:46,440 EXPECT AMINO ACIDS, LIPIDS, EVEN 2021 01:33:46,440 --> 01:33:50,400 SHORT OLIGOMERS OF NUCLEIC 2022 01:33:50,400 --> 01:33:51,640 ACIDS. TO HAVE EXISTED AND OF 2023 01:33:51,640 --> 01:33:55,520 COURSE THE OTHER EVIDENCE IS 2024 01:33:55,520 --> 01:33:59,280 CERTAIN METEORITES. THESE 2025 01:33:59,280 --> 01:34:02,720 CARBONATION CHONDRITES SOME HAVE 2026 01:34:02,720 --> 01:34:04,680 70 DIFFERENT AMINO ACIDS IN THEM 2027 01:34:04,680 --> 01:34:07,480 SO WE KNOW THIS TYPE OF 2028 01:34:07,480 --> 01:34:09,120 CHEMISTRY, GOES ON AND ACTUALLY 2029 01:34:09,120 --> 01:34:12,440 GOES ON FAIRLY LONGLY, IN THE 2030 01:34:12,440 --> 01:34:14,600 EARLY HISTORY OF SULFUR SYSTEMS. 2031 01:34:14,600 --> 01:34:17,160 SO THAT IS EVERYTHING WE KNOW 2032 01:34:17,160 --> 01:34:22,040 COMES FROM THOSE AND NONE 2033 01:34:22,040 --> 01:34:23,920 BASICALLY COMES FROM A WELL 2034 01:34:23,920 --> 01:34:27,720 PRESERVED GEOLOGIC RECORD OF THE 2035 01:34:27,720 --> 01:34:30,520 FIRST 500 MILLION YEARS HISTORY. 2036 01:34:30,520 --> 01:34:32,520 >> I BELIEVE IS IT TRUE THAT 2037 01:34:32,520 --> 01:34:35,600 RADIO ICE TOPIC DECAY -- 2038 01:34:35,600 --> 01:34:38,160 ISOTOPIC DECAY IN ZIRCON IS A 2039 01:34:38,160 --> 01:34:40,200 TOOL FOR DETERMINING THE AGE AT 2040 01:34:40,200 --> 01:34:42,840 LEAST ZIRCON, THE ROCK. CAN YOU 2041 01:34:42,840 --> 01:34:45,280 EXPLAIN WHETHER A ZIRCON IS? NOT 2042 01:34:45,280 --> 01:34:47,160 SURE ALL OF US UNDERSTAND THAT. 2043 01:34:47,160 --> 01:34:50,840 >> WELL IT IS A MINERAL. IF YOU 2044 01:34:50,840 --> 01:34:54,960 HAVE JEWELRY MADE OF CUBIC 2045 01:34:54,960 --> 01:34:56,080 ZIRCONIUM, THAT IS INDUSTRIALLY 2046 01:34:56,080 --> 01:34:59,040 MADE ZIRCONS USED IN THE JEWELRY 2047 01:34:59,040 --> 01:35:01,280 INDUSTRY. BUT IT IS BASICALLY 2048 01:35:01,280 --> 01:35:03,760 PARTICULARLY IN ROCKS LIKE 2049 01:35:03,760 --> 01:35:06,760 GRANITE, THOUGH NOT EXCLUSIVELY. 2050 01:35:06,760 --> 01:35:08,760 DIFFERENT ELEMENTS ARE 2051 01:35:08,760 --> 01:35:10,120 INCORPORATED INTO DIFFERENT 2052 01:35:10,120 --> 01:35:12,760 MINERALS UNDER DIFFERENT 2053 01:35:12,760 --> 01:35:13,360 CONDITIONS OF TEMPERATURE AND 2054 01:35:13,360 --> 01:35:18,560 PRESSURE. SOME ELEMENTS ARE NOT 2055 01:35:18,560 --> 01:35:21,200 EASILY INCORPORATED INTO ROCK 2056 01:35:21,200 --> 01:35:24,880 FORMING MINERALS SO THEY ARE 2057 01:35:24,880 --> 01:35:27,480 ONLY TAKEN INTO MINERAL LATTICES 2058 01:35:27,480 --> 01:35:30,800 FAIRLY LATE IN THE HISTORY OF A 2059 01:35:30,800 --> 01:35:34,880 MAGMA. ONE OF THOSE IS ZIRCONIUM 2060 01:35:34,880 --> 01:35:39,640 WHICH THEN REACTS WITH SILICA 2061 01:35:39,640 --> 01:35:42,720 AND FOR OXYGEN TO MAKE A 2062 01:35:42,720 --> 01:35:46,600 MINERAL. I CONSIDERED ZIRCONIUM 2063 01:35:46,600 --> 01:35:50,320 TO BE THE GEOLOGIST EQUIVALENT 2064 01:35:50,320 --> 01:35:53,920 OF THE FLIGHT RECORDERS, WHEN AN 2065 01:35:53,920 --> 01:35:55,800 AIRPLANE GOES DOWN IT IS FLIGHT 2066 01:35:55,800 --> 01:35:58,160 RECORDER IS TOUGH ENOUGH THAT IT 2067 01:35:58,160 --> 01:35:59,720 RESISTS DESTRUCTION AND TELLS 2068 01:35:59,720 --> 01:36:01,600 YOU A LOT ABOUT WHAT HAPPENED. 2069 01:36:01,600 --> 01:36:06,240 AND ZIRCONS ARE VERY HARD TO 2070 01:36:06,240 --> 01:36:07,280 RECRYSTALLIZE, VERY HARD FOR 2071 01:36:07,280 --> 01:36:08,520 FLUIDS TO PERCOLATE THROUGH THEM 2072 01:36:08,520 --> 01:36:12,280 AND CHANGE THEIR CHEMISTRY. 2073 01:36:12,280 --> 01:36:17,200 BECAUSE THEY INCORPORATE URANIUM 2074 01:36:17,200 --> 01:36:18,200 WHICH HAS TWO DIFFERENT RADIO 2075 01:36:18,200 --> 01:36:23,800 ACTIVE ISOTOPE, THEY ARE VERY, 2076 01:36:23,800 --> 01:36:27,080 VERY GOOD FOR DETERMINING AGES 2077 01:36:27,080 --> 01:36:30,000 WHEN THOSE CRYSTALS FORMED. SO 2078 01:36:30,000 --> 01:36:33,080 WE HAVE DONE WORK IN MY OWN WORK 2079 01:36:33,080 --> 01:36:37,040 WHERE WE HAVE COLLECTED VOLCANIC 2080 01:36:37,040 --> 01:36:38,040 ASHES THAT WERE INNER LAYERED 2081 01:36:38,040 --> 01:36:41,080 WITH SEDIMENTS THAT HAVE FOSSILS 2082 01:36:41,080 --> 01:36:43,400 AND ENVIRONMENTAL CLUES IN THEM 2083 01:36:43,400 --> 01:36:45,920 AND THE ZIRCON IN THOSE ASHES 2084 01:36:45,920 --> 01:36:48,920 PROVIDE A PRECISE DATE FOR AL 2085 01:36:48,920 --> 01:36:51,280 THE THINGS WE ARE SEEING. SO 2086 01:36:51,280 --> 01:36:53,000 BASICALLY IT IS MINERALS THAT 2087 01:36:53,000 --> 01:36:56,440 INCORPORATE RADIO ACTIVE 2088 01:36:56,440 --> 01:36:58,200 ISOTOPES AND THOSE RADIO ACTIVE 2089 01:36:58,200 --> 01:36:59,960 ISOTOPES DECAY AT RATES THAT CAN 2090 01:36:59,960 --> 01:37:02,600 BE MEASURED MANY THE LABORATORY 2091 01:37:02,600 --> 01:37:05,240 AND THEREFORE CAN BE USED TO 2092 01:37:05,240 --> 01:37:08,040 TELL AGE OF ROCKS. . 2093 01:37:08,040 --> 01:37:10,160 >> IS IT STILL FELT GENERALLY 2094 01:37:10,160 --> 01:37:12,600 SPEAKING THE OLDEST ROCKS ON 2095 01:37:12,600 --> 01:37:15,480 EARTH ARE SOMETHING LIKE ABOUT 4 2096 01:37:15,480 --> 01:37:16,880 BILLION YEARS AND THE MOON ROCKS 2097 01:37:16,880 --> 01:37:20,840 ARE ABOUT THE SAME? IS THAT 2098 01:37:20,840 --> 01:37:24,880 STILL -- IS THAT THE STATE AT 2099 01:37:24,880 --> 01:37:25,120 PRESENT? 2100 01:37:25,120 --> 01:37:27,520 >> YEAH. ON EARTH YOU ARE 2101 01:37:27,520 --> 01:37:29,960 EXACTLY RIGHT. THERE IS VERY 2102 01:37:29,960 --> 01:37:32,000 HIGHLY METAMORPHOSED ROCKS IN 2103 01:37:32,000 --> 01:37:33,520 NORTHERN CANADA WHICH HAVE BEEN 2104 01:37:33,520 --> 01:37:37,520 DATED WITH ZIRCONS AT A SHADE 2105 01:37:37,520 --> 01:37:41,960 OVER 4 BILLION YEARS. AS YOU GO 2106 01:37:41,960 --> 01:37:43,440 BACK FURTHER IN TIME, EROSION 2107 01:37:43,440 --> 01:37:46,240 TENDS TO GET AND ME FA MORPHISM 2108 01:37:46,240 --> 01:37:49,760 TAKES UPPER HAND OVER UPPER 2109 01:37:49,760 --> 01:37:51,480 FORMATION SO WE DON'T HAVE A 2110 01:37:51,480 --> 01:37:54,080 GOOD RECORD OF ALMOST THE FIRST 2111 01:37:54,080 --> 01:37:57,680 BILLION YEARS OF EARTH HISTORY. 2112 01:37:57,680 --> 01:38:00,480 THE MOON HAS SOME PEOPLE IN THE 2113 01:38:00,480 --> 01:38:01,640 AUDIENCE WILL PROBABLY KNOW IS 2114 01:38:01,640 --> 01:38:06,200 THOUGHT TO ORIGINATED FROM 2115 01:38:06,200 --> 01:38:07,160 BOMBARDMENT EARLY IN THE 2116 01:38:07,160 --> 01:38:09,200 FORMATION HISTORY OF THE EARTH. 2117 01:38:09,200 --> 01:38:14,000 WHEN THEETH WAS ALMOST FULLY 2118 01:38:14,000 --> 01:38:16,760 FORMED, IT WAS CLOBBERED BY A 2119 01:38:16,760 --> 01:38:19,200 MARS SIZE STRUCTURE. THAT 2120 01:38:19,200 --> 01:38:24,920 BASICALLY EJECTED A LOTS OF 2121 01:38:24,920 --> 01:38:27,280 MATERIAL INTO SPACE BUT BECAUSE 2122 01:38:27,280 --> 01:38:29,840 OF GRAVITY, MUCH OF IT STAYED IN 2123 01:38:29,840 --> 01:38:30,960 EARTH'S ORBIT AND WAS 2124 01:38:30,960 --> 01:38:34,080 RECONSTITUTED AS THE MOON. SO WE 2125 01:38:34,080 --> 01:38:41,440 DO HAVE SOME VERY OLD MATERIALS, 2126 01:38:41,440 --> 01:38:42,040 4 BILLION YEARS PLUS MATERIALS 2127 01:38:42,040 --> 01:38:48,560 ON THE MOON, FAMOUSLY, APOLLO 2128 01:38:48,560 --> 01:38:50,840 ASTRONAUTS CHECKED LUNAR SAMPLE 2129 01:38:50,840 --> 01:38:51,800 SEVERAL PARTS OF THE MOON AND 2130 01:38:51,800 --> 01:38:54,200 WHEN THEY DATED THEM THEY CAME 2131 01:38:54,200 --> 01:38:55,040 AFTER 3.9 BILLION YEARS. T THAT 2132 01:38:55,040 --> 01:38:59,400 WAS USED TO ARGUE FOR WHAT HAS 2133 01:38:59,400 --> 01:39:01,640 BEEN CALLED LATE HEAVY 2134 01:39:01,640 --> 01:39:04,320 BOMBARDMENT, THE IDEA THAT ABOUT 2135 01:39:04,320 --> 01:39:06,920 3.9 BILLION YEARS AGO PERHAPS BY 2136 01:39:06,920 --> 01:39:10,280 JUPITER AND SATURN COMING IN TO 2137 01:39:10,280 --> 01:39:12,160 ORBITAL RESIDENCE, A LOT OF 2138 01:39:12,160 --> 01:39:14,360 MATERIAL FROM THE SOLAR SYSTEM, 2139 01:39:14,360 --> 01:39:15,800 OUTER SOLAR SYSTEM WAS EJECTED 2140 01:39:15,800 --> 01:39:17,400 INTO THE INNER SOLAR SYSTEM AND 2141 01:39:17,400 --> 01:39:22,800 THERE IS THIS MAJOR FLUX OF 2142 01:39:22,800 --> 01:39:23,880 METEORITES ON TO THE INNER PART 2143 01:39:23,880 --> 01:39:28,960 OF THE SOLAR SYSTEM. IT IS NOW 2144 01:39:28,960 --> 01:39:31,280 PRETTY CLEAR THAT ALL OF THOSE 2145 01:39:31,280 --> 01:39:32,480 MATERIALS COLLECTED ON THE MOON 2146 01:39:32,480 --> 01:39:37,040 CAME FROM A SINGLE LARGE IMPACT 2147 01:39:37,040 --> 01:39:41,360 AND SO WHILE IT IS POSSIBLE 2148 01:39:41,360 --> 01:39:43,600 THERE WAS SOME BOMBARDMENT STAGE 2149 01:39:43,600 --> 01:39:46,280 OF THE TYPE BEING TALKED ABOUT, 2150 01:39:46,280 --> 01:39:49,680 BUT IF THERE WAS IT MIGHT HAVE 2151 01:39:49,680 --> 01:39:51,560 HAPPENED 4.4 BILLION YEARS AGO 2152 01:39:51,560 --> 01:39:56,040 RATHER THAN LATER. IT IS A 2153 01:39:56,040 --> 01:39:57,840 COMPLICATED PICTURE. 2154 01:39:57,840 --> 01:40:00,880 >> I GATHER. WE HAVE AN 2155 01:40:00,880 --> 01:40:01,680 INTERESTING QUESTION FROM 2156 01:40:01,680 --> 01:40:06,000 MICHAEL. WHO SAYS THE IDEA OF 2157 01:40:06,000 --> 01:40:09,800 DEEP SEA HYDRO THERMAL VENTS WAS 2158 01:40:09,800 --> 01:40:12,600 PUT FORWARD TO SHIELD EARLY LIFE 2159 01:40:12,600 --> 01:40:16,200 FROM ULTRAVIOLET DAMAGE. SO A 2160 01:40:16,200 --> 01:40:18,360 GREAT QUESTION IS WHETHER 2161 01:40:18,360 --> 01:40:21,000 ULTRAVIOLET WAS REALLY DAMAGING 2162 01:40:21,000 --> 01:40:25,480 OR COULD BE USED AS A SOURCE OF 2163 01:40:25,480 --> 01:40:27,400 ENERGY FOR A PREBIOTIC 2164 01:40:27,400 --> 01:40:27,840 CHEMISTRY. 2165 01:40:27,840 --> 01:40:31,840 >> GREAT QUESTION. PEOPLE HAVE 2166 01:40:31,840 --> 01:40:33,840 USED VARIOUS TYPES OF RADIATION 2167 01:40:33,840 --> 01:40:36,840 AS SOURCES FOR ENERGY SOURCES 2168 01:40:36,840 --> 01:40:40,080 FOR CHEMISTRY. SO IN THAT REGARD 2169 01:40:40,080 --> 01:40:42,720 I THINK ULTRAVIOLET MAY WELL 2170 01:40:42,720 --> 01:40:46,440 HAVE BEEN PART OF THE MIXTURE OF 2171 01:40:46,440 --> 01:40:49,080 ENERGY SOURCES FOR DRIVING 2172 01:40:49,080 --> 01:40:49,880 PREBIOTIC REACTIONS. THE OTHER 2173 01:40:49,880 --> 01:40:53,120 THING OF COURSE IS THAT WHEN I 2174 01:40:53,120 --> 01:40:56,440 WAS A STUDENT PEOPLE WERE VERY 2175 01:40:56,440 --> 01:40:58,160 WORRIED THAT SINCE THERE WAS NO 2176 01:40:58,160 --> 01:41:01,000 OXYGEN ON THE EARLY EARTH THERE 2177 01:41:01,000 --> 01:41:02,320 WOULDN'T HAVE BEEN AN OZONE 2178 01:41:02,320 --> 01:41:05,080 SHIELD THE WAY THERE IS TODAY. 2179 01:41:05,080 --> 01:41:07,040 SO THEREFORE HOW COULD LIFE GET 2180 01:41:07,040 --> 01:41:10,760 GOING. THEN PEOPLE FOUND OUTUP 2181 01:41:10,760 --> 01:41:12,280 ABOUT A MILLIMETER OF SAND 2182 01:41:12,280 --> 01:41:15,280 GRAINS IS A PRETTY EFFECTIVE 2183 01:41:15,280 --> 01:41:18,600 SHIELD AGAINST TYPES OF UV THAT 2184 01:41:18,600 --> 01:41:22,360 DESTROY MOLECULES. COUPLE OF 2185 01:41:22,360 --> 01:41:26,480 METERS OF WATER WILL DO IT. AS 2186 01:41:26,480 --> 01:41:29,800 SOME PEOPLE LISTENING MAY WELL 2187 01:41:29,800 --> 01:41:31,480 KNOW, A LOT OF MICROBES ARE VERY 2188 01:41:31,480 --> 01:41:34,160 VERY GOOD ABOUT DNA REPAIR. 2189 01:41:34,160 --> 01:41:38,160 THERE IS A BACTERIA CALLED 2190 01:41:38,160 --> 01:41:39,840 DINACOCCUS FOUND INSIDE WALLS OF 2191 01:41:39,840 --> 01:41:43,640 NUCLEAR REACTORS SO EVEN IF YOU 2192 01:41:43,640 --> 01:41:46,920 HAVE DESTRUCTIVE UV, BACTERIA 2193 01:41:46,920 --> 01:41:51,200 AND ARCHEA HAVE RATHER MARKEDLY 2194 01:41:51,200 --> 01:41:53,840 SOPHISTICATED WAYS OF MAKING 2195 01:41:53,840 --> 01:41:58,520 REPAIRS. SO YES, I THINK -- I 2196 01:41:58,520 --> 01:42:01,800 THINK TO BE ACTUALLY IN TERMS OF 2197 01:42:01,800 --> 01:42:03,080 HISTORY, IT WAS ONLY IN THE 2198 01:42:03,080 --> 01:42:05,520 1970s THE PEOPLE STARTED 2199 01:42:05,520 --> 01:42:08,200 LOOKING AT MID OCEAN RIDGES AND 2200 01:42:08,200 --> 01:42:09,840 FINDING THAT THEY WERE PLACES OF 2201 01:42:09,840 --> 01:42:11,080 HIGH BIOLOGICAL DIVERSITY IN THE 2202 01:42:11,080 --> 01:42:13,040 MIDDLE OF THE OCEAN OF THE THAT 2203 01:42:13,040 --> 01:42:16,000 WAS ACTUALLY TRANSFORMATIVE. I 2204 01:42:16,000 --> 01:42:19,800 THINK THAT IN SOME WAYS ALSO 2205 01:42:19,800 --> 01:42:22,120 FUELED THE IDEA THAT NOT ONLY 2206 01:42:22,120 --> 01:42:25,360 WERE MID OCEAN RIDGES 2207 01:42:25,360 --> 01:42:26,680 BIOLOGICALLY IMPORTANT BUT COULD 2208 01:42:26,680 --> 01:42:29,560 BE PRE-BIOLOGICALLY IMPORTANT. I 2209 01:42:29,560 --> 01:42:32,960 DON'T DISPUTE THAT INFERENCE AT 2210 01:42:32,960 --> 01:42:36,200 ALL. I JUST THINK ONE CAN ONLY 2211 01:42:36,200 --> 01:42:41,840 PLAY THE UV CARD SO STRONGLY AND 2212 01:42:41,840 --> 01:42:48,080 AS THE QUESTION IMPLIED, ON THE 2213 01:42:48,080 --> 01:42:51,400 PREBIOTIC EARTH YOU CAN UV MAY 2214 01:42:51,400 --> 01:42:52,440 HAVE BEEN YOUR FRIEND IN TERMS 2215 01:42:52,440 --> 01:42:57,520 OF DRIVING PREBIOTIC REACTIONS. 2216 01:42:57,520 --> 01:43:06,800 >> I THINK THAT YOGI BERRA, IT'S 2217 01:43:06,800 --> 01:43:07,960 GREAT CREDIT FOR A STATEMENT 2218 01:43:07,960 --> 01:43:12,800 THAT I BELIEVE WAS REALLY MADE 2219 01:43:12,800 --> 01:43:14,600 BY NEIL SPORE. THAT IS, IT IS 2220 01:43:14,600 --> 01:43:16,280 DIFFICULT TO PREDICT THINGS 2221 01:43:16,280 --> 01:43:21,480 PARTICULARLY ABOUT THE FUTURE. 2222 01:43:21,480 --> 01:43:23,720 BUT BUNCH OF QUESTIONS THAT ASKS 2223 01:43:23,720 --> 01:43:26,640 YOUR OPINION ABOUT THE FUTURE. 2224 01:43:26,640 --> 01:43:28,000 IF YOU DON'T MIND WE CAN 2225 01:43:28,000 --> 01:43:31,320 CONSIDER SOME OF THOSE. 2226 01:43:31,320 --> 01:43:36,560 >> SURE. 2227 01:43:36,560 --> 01:43:38,240 >> DO YOU THINK THAT (INAUDIBLE) 2228 01:43:38,240 --> 01:43:39,600 LIFE IS FREQUENT OR RARE IN THE 2229 01:43:39,600 --> 01:43:40,760 UNIVERSE? 2230 01:43:40,760 --> 01:43:44,520 >> IT IS INTERESTING. I ALWAYS 2231 01:43:44,520 --> 01:43:46,680 THINK -- IT IS A QUESTION THAT 2232 01:43:46,680 --> 01:43:49,600 WE CAN ALL ASK AND I THINK OF 2233 01:43:49,600 --> 01:43:51,160 TWO BOOKS THAT WERE PUBLISHED 2234 01:43:51,160 --> 01:43:56,760 COUPLE OF DECADES AGO. ONE WAS 2235 01:43:56,760 --> 01:43:58,560 BY WARREN BROWNLY CALLED RARE 2236 01:43:58,560 --> 01:44:02,880 EARTH. THEY CONCLUDED THAT LIFE 2237 01:44:02,880 --> 01:44:05,720 WAS PROBABLY REPLETE IN THE 2238 01:44:05,720 --> 01:44:07,200 UNIVERSE BUT IT WAS ALMOST 2239 01:44:07,200 --> 01:44:10,000 ALWAYS MICROBIAL AND THAT 2240 01:44:10,000 --> 01:44:11,760 COMPLEX TECHNOLOGICAL LIFE WAS 2241 01:44:11,760 --> 01:44:16,240 RARE. SOME YEARS LATER SIMON CON 2242 01:44:16,240 --> 01:44:19,240 WAY MORRIS, A PALEONTOLOGIST IN 2243 01:44:19,240 --> 01:44:20,600 CAMBRIDGE WHO WROTE A BOOK IN 2244 01:44:20,600 --> 01:44:22,040 WHICH HE SAID WELL, VERY, VERY 2245 01:44:22,040 --> 01:44:24,760 HARD TO MAKE LIFE, THEREFORE 2246 01:44:24,760 --> 01:44:26,160 LIFE MUST BE RARE IN THE 2247 01:44:26,160 --> 01:44:30,960 UNIVERSE. BUT ONCE YOU GET LIFE 2248 01:44:30,960 --> 01:44:34,320 INTELLIGENCE IS ALMOST 2249 01:44:34,320 --> 01:44:35,680 INEVITABLE. WHAT IS INTERESTING 2250 01:44:35,680 --> 01:44:39,280 ABOUT THIS IS THEY BOTH HAD 2251 01:44:39,280 --> 01:44:42,040 RECOURSE TO EXACTLY THE SAME 2252 01:44:42,040 --> 01:44:42,880 FACTUAL INFORMATION WHICH IS 2253 01:44:42,880 --> 01:44:46,080 THAT LIFE EXISTS ON EARTH. THAT 2254 01:44:46,080 --> 01:44:49,720 IS -- IN A FACTUAL SENSE ALL WE 2255 01:44:49,720 --> 01:44:54,400 KNOW ABOUT LIFE. MOST PEOPLE 2256 01:44:54,400 --> 01:44:59,320 THAT I KNOW AND WORK WITH, THINK 2257 01:44:59,320 --> 01:45:03,760 THAT IT IS LIKELY THAT LIFE 2258 01:45:03,760 --> 01:45:05,400 EXISTS ELSEWHERE IN THE 2259 01:45:05,400 --> 01:45:08,320 UNIVERSE, THAT IN SOME WAYS IF 2260 01:45:08,320 --> 01:45:12,000 EARTH WERE A SINGULARITY, THAT 2261 01:45:12,000 --> 01:45:14,760 WOULD BE ALMOST HARDER TO 2262 01:45:14,760 --> 01:45:15,960 CONTEMPLATE THAN THE IDEA THAT 2263 01:45:15,960 --> 01:45:23,200 LIFE IS OUT THERE. HAVING SAID 2264 01:45:23,200 --> 01:45:28,320 THAT, IT IS COMPLETE SPECULATION 2265 01:45:28,320 --> 01:45:32,400 WHAT KIND OF LIFE MAY EXIST IN 2266 01:45:32,400 --> 01:45:33,240 WHAT QUANTITIES DIMENSIONS IN 2267 01:45:33,240 --> 01:45:37,280 OTHER PLACES. PARTS OF THE 2268 01:45:37,280 --> 01:45:39,120 PROBLEM IS THE WAY WE LOOK FOR 2269 01:45:39,120 --> 01:45:42,360 LIFE BEYOND THE EARTH. OUR OWN 2270 01:45:42,360 --> 01:45:44,520 SOLAR SYSTEM WE CAN GO THERE. WE 2271 01:45:44,520 --> 01:45:46,240 HAVE BEEN TO MARS. WE ARE 2272 01:45:46,240 --> 01:45:49,880 PROBABLY GOING TO SEND 2273 01:45:49,880 --> 01:45:51,560 INTERESTING MISSIONS TO PLACES 2274 01:45:51,560 --> 01:45:55,320 MOONS OF OUTER PLANETS LIKE IN 2275 01:45:55,320 --> 01:45:58,080 TITAN WHICH ARE POSSIBILITIES 2276 01:45:58,080 --> 01:46:00,600 FOR LIFE AS WE. THERE E AT 2277 01:46:00,600 --> 01:46:02,000 LEAST WE CAN GO AND WE CAN DO 2278 01:46:02,000 --> 01:46:03,680 EXPERIMENTS AN COLLECT SAMPLES. 2279 01:46:03,680 --> 01:46:05,880 AND ANSWER MORE DEFINITIVELY 2280 01:46:05,880 --> 01:46:10,080 WHETHER LIFE IS PRESENT IN THE 2281 01:46:10,080 --> 01:46:10,680 CASE OF MARSES WHETHER IT MIGHT 2282 01:46:10,680 --> 01:46:12,040 HAVE BEEN PRESENT IN THE PAST. 2283 01:46:12,040 --> 01:46:13,480 THAT BECOMES HARD ONCE YOU GET 2284 01:46:13,480 --> 01:46:18,760 BEYOND OUR OWN SOLAR SYSTEM. SO 2285 01:46:18,760 --> 01:46:22,240 IN OUR OWN GALACTIC 2286 01:46:22,240 --> 01:46:23,800 NEIGHBORHOOD, COUPLE OF TENS OF 2287 01:46:23,800 --> 01:46:28,960 LIGHT YEARS, WE DEVELOPED THE 2288 01:46:28,960 --> 01:46:31,360 CAPACITY TO LOOK AT COMPOSITION 2289 01:46:31,360 --> 01:46:35,440 OF ATMOSPHERES. AND THERE IS A 2290 01:46:35,440 --> 01:46:37,920 DEBATE TO WHETHER ANY 2291 01:46:37,920 --> 01:46:40,760 ATMOSPHERIC COMPOSITION IS 2292 01:46:40,760 --> 01:46:43,760 ACTUALLY DIAGNOSTIC FOR LIFE BUT 2293 01:46:43,760 --> 01:46:45,280 IF WE ARE GOING TO FIND EVIDENCE 2294 01:46:45,280 --> 01:46:49,640 OF LIFE IN THOSE PLANETS THE 2295 01:46:49,640 --> 01:46:51,160 MOST LIKELY WAY TO LOOK FOR IT 2296 01:46:51,160 --> 01:46:52,480 IS ON THE BASIS OF WHAT IT DOES 2297 01:46:52,480 --> 01:46:55,480 TO THE ENVIRONMENT. THEN FOR 2298 01:46:55,480 --> 01:46:56,880 MOST OF THE UNIVERSE WE ARE ONLY 2299 01:46:56,880 --> 01:46:59,200 GOING TO KNOW IF SOMEBODY TELLS 2300 01:46:59,200 --> 01:47:01,920 US BECAUSE WE JUST DON'T HAVE 2301 01:47:01,920 --> 01:47:06,080 THE CAPACITY TO DO THINGS LIKE 2302 01:47:06,080 --> 01:47:12,040 EITHER GO THERE OR LOOK AT THAT 2303 01:47:12,040 --> 01:47:14,920 ENVIRONMENT. SO IT IS A GREAT 2304 01:47:14,920 --> 01:47:16,880 QUESTION. I THINK A LOT OF THE 2305 01:47:16,880 --> 01:47:18,160 BEST WRITING ON THE 2306 01:47:18,160 --> 01:47:19,880 POSSIBILITIES OF LIFE AND I SAY 2307 01:47:19,880 --> 01:47:21,480 THIS IN ALL SERIOUSNESS IS 2308 01:47:21,480 --> 01:47:22,720 SCIENCE FICTION AND NOT 2309 01:47:22,720 --> 01:47:32,560 SCIENTIFIC LITERATURE. I THINK 2310 01:47:32,560 --> 01:47:33,560 WHAT (INAUDIBLE) THINKS ABOUT 2311 01:47:33,560 --> 01:47:35,680 WHEN HE THINKS ABOUT ET IS ABOUT 2312 01:47:35,680 --> 01:47:37,240 AS VALID AS WHAT I THINK ABOUT 2313 01:47:37,240 --> 01:47:38,440 WHEN I THINK ABOUT LOOKING FOR 2314 01:47:38,440 --> 01:47:42,040 LIFE ON MARS. STEVEN STEELBURG. 2315 01:47:42,040 --> 01:47:44,440 >> IT IS INTERESTING, SEEMS TO 2316 01:47:44,440 --> 01:47:47,640 ME IT WASN'T SO VERY LONG AGO 2317 01:47:47,640 --> 01:47:48,280 THESE QUESTIONS LIKE THE KINDS 2318 01:47:48,280 --> 01:47:51,320 WE ARE TALKING ABOUT, WE ARE 2319 01:47:51,320 --> 01:47:54,360 LIMBED TO SCIENCE FICTION 2320 01:47:54,360 --> 01:48:01,440 WRITERS AND TO CARTOON STRIPS, 2321 01:48:01,440 --> 01:48:04,360 (INAUDIBLE) WHICH BRINGS UP AN 2322 01:48:04,360 --> 01:48:05,760 INTERESTING QUESTION ABOUT IN 2323 01:48:05,760 --> 01:48:08,320 THE PAST HALF CENTURY, WHAT IS 2324 01:48:08,320 --> 01:48:12,720 YOUR TAKE ON HOW SORT OF PUBLIC 2325 01:48:12,720 --> 01:48:16,440 AND THE SCIENCE ATTITUDES VIEW 2326 01:48:16,440 --> 01:48:17,880 OFS ABOUT THE ORIGIN OF LIFE 2327 01:48:17,880 --> 01:48:20,880 HAVE CHANGED? 2328 01:48:20,880 --> 01:48:22,280 >> BOY, THAT IS AN INTERESTING 2329 01:48:22,280 --> 01:48:29,880 QUESTION. MY GUESS IS THAT OVER 2330 01:48:29,880 --> 01:48:34,960 THE PAST 50 YEARS RATHER THAN 2331 01:48:34,960 --> 01:48:40,440 THERE BEING SOME STRONG 2332 01:48:40,440 --> 01:48:41,760 BACTERIAL SHIFT IN THE ORBIT AS 2333 01:48:41,760 --> 01:48:43,840 A WHOLE, I GUESS THE DIVISION 2334 01:48:43,840 --> 01:48:47,440 BETWEEN PEOPLE WHO ARE INTENT TO 2335 01:48:47,440 --> 01:48:49,280 THINK LIFE IN SOME WAY 2336 01:48:49,280 --> 01:48:53,160 ORIGINATED BY NATURAL CAUSES, BY 2337 01:48:53,160 --> 01:48:55,480 THOSE WHO THINKS IT WAS DIVINE 2338 01:48:55,480 --> 01:48:58,760 INSPIRATION. I DO GET THE 2339 01:48:58,760 --> 01:49:05,520 FEELING THAT -- THOSE WHO DOUBT 2340 01:49:05,520 --> 01:49:07,440 PHYSICAL PROCESSES FROM THE 2341 01:49:07,440 --> 01:49:08,560 ORIGINS OF LIFE TEND TO BE THE 2342 01:49:08,560 --> 01:49:09,720 SAME PEOPLE WHO ARE NOT 2343 01:49:09,720 --> 01:49:10,880 CONVINCED THAT THERE IS A THING 2344 01:49:10,880 --> 01:49:14,960 CALLED EVOLUTIO EVOLUTION COMESM 2345 01:49:14,960 --> 01:49:19,880 CONSERVATIVE ELEMENTS NOT JUST 2346 01:49:19,880 --> 01:49:23,000 IN ISLAM AND CHRISTIANITY AND 2347 01:49:23,000 --> 01:49:27,160 THINGS LIKE THIS, WHEREAS OTHER 2348 01:49:27,160 --> 01:49:30,680 PORTIONS OF THE POPULATION ARE 2349 01:49:30,680 --> 01:49:32,400 QUITE HAPPY TO THINK THAT 2350 01:49:32,400 --> 01:49:33,920 EVOLUTION IS A THING, IT HAPPENS 2351 01:49:33,920 --> 01:49:36,640 WE CAN OBSERVE IT WE CAN MODEL 2352 01:49:36,640 --> 01:49:39,400 IT WE CAN DO IT EXPERIMENTALLY 2353 01:49:39,400 --> 01:49:43,160 AND SO THEREFORE, EVEN IF WE 2354 01:49:43,160 --> 01:49:47,920 DON'T UNDERSTAND HOW LIFE 2355 01:49:47,920 --> 01:49:49,200 ORIGINATED, THAT THERE IS REASON 2356 01:49:49,200 --> 01:49:50,840 TO BELIEVE THAT THERE ARE 2357 01:49:50,840 --> 01:49:53,280 PHYSICAL CAUSES THAT LEAD TO 2358 01:49:53,280 --> 01:49:57,640 THAT. I GUESS WHAT HAS CHANGED 2359 01:49:57,640 --> 01:49:58,520 MORE THAN ANYTHING AND MAYBE 2360 01:49:58,520 --> 01:50:02,240 THIS WHERE THE QUESTION COMES 2361 01:50:02,240 --> 01:50:06,600 FROM, IS THAT 50 YEARS AGO, IF 2362 01:50:06,600 --> 01:50:11,840 WE THOUGHT DID LIFE BEGIN ON 2363 01:50:11,840 --> 01:50:16,080 MARS, ISAAC OR RAY BRAD BURY ARE 2364 01:50:16,080 --> 01:50:18,320 THE PEOPLE YOU WOULD LOOK TO. 2365 01:50:18,320 --> 01:50:22,720 NOW, WE HAVE BEEN THERE. WE 2366 01:50:22,720 --> 01:50:25,000 ACTUALLY CAN CONSTRAIN ISSUES 2367 01:50:25,000 --> 01:50:27,320 MUCH, MUCH MORE THAN WE COULD 2368 01:50:27,320 --> 01:50:30,680 THEN. THAT DOES GIVE RISE TO AT 2369 01:50:30,680 --> 01:50:35,280 LEAST THE FEELING THAT THROUGH 2370 01:50:35,280 --> 01:50:37,280 THE REMARKABLE PROGRESS WE HAVE 2371 01:50:37,280 --> 01:50:43,120 MADE IN OBSERVATION,S NOT JUST 2372 01:50:43,120 --> 01:50:47,720 SOLAR SYSTEM THE UNIVERSE, I 2373 01:50:47,720 --> 01:50:50,160 HAVE HUGE ADMONITION (INAUDIBLE) 2374 01:50:50,160 --> 01:50:54,360 POSSIBLE. THEN THAT I THINK DOES 2375 01:50:54,360 --> 01:50:58,040 GIVE RISE TO THE SORT OF THING 2376 01:50:58,040 --> 01:51:00,760 THAT PERSON IS A NATURAL SYSTEM 2377 01:51:00,760 --> 01:51:04,120 AND IT OPERATES UNDER NATURAL 2378 01:51:04,120 --> 01:51:06,160 LAWS. I THINK THAT IS ABOUT THE 2379 01:51:06,160 --> 01:51:09,480 BEST APPROACH TO AND ADVANCE 2380 01:51:09,480 --> 01:51:11,160 ANSWER I CAN GIVE. 2381 01:51:11,160 --> 01:51:15,400 >> IN YOUR POSITION AS A LEADING 2382 01:51:15,400 --> 01:51:18,520 ACADEMIC GEOLOGIST BIOLOGIST, 2383 01:51:18,520 --> 01:51:22,360 AND ALSO INVOLVED WITH NASA AND 2384 01:51:22,360 --> 01:51:24,560 OTHER ORGANIZATIONS AND GROUPS, 2385 01:51:24,560 --> 01:51:26,120 DO YOU HAVE A FEELING AS TO 2386 01:51:26,120 --> 01:51:27,600 WHETHER THE KINDS OF QUESTIONS 2387 01:51:27,600 --> 01:51:30,880 YOU ARE INTERESTED IN ARE MORE 2388 01:51:30,880 --> 01:51:34,560 LIKELY TO BE ANSWERED BY MANNED 2389 01:51:34,560 --> 01:51:36,920 EXPLORATION OR BY UNMANNED 2390 01:51:36,920 --> 01:51:43,920 EXPLORATION? ROBOTICS AND 2391 01:51:43,920 --> 01:51:44,680 TELESCOPES IN SPACE? 2392 01:51:44,680 --> 01:51:48,640 >> YEAH, WELL I THINK UNTIL WE 2393 01:51:48,640 --> 01:51:50,200 FIGURE OUT HOW TO BREAK THE LAWS 2394 01:51:50,200 --> 01:51:51,920 OF PHYSICS AND GETTING TO SEE 2395 01:51:51,920 --> 01:51:54,800 THE SPEED OF LIGHT, IN OUR SOLAR 2396 01:51:54,800 --> 01:51:56,400 SYSTEM, THAT IS THE ONLY PLACE 2397 01:51:56,400 --> 01:52:01,000 HUMANS ARE GOING TO SEND BUT ON 2398 01:52:01,000 --> 01:52:02,480 -- THIS DEBATE GOES ON ALL THE 2399 01:52:02,480 --> 01:52:05,520 TIME FOR MARS. I ACTUALLY HAVE 2400 01:52:05,520 --> 01:52:07,760 FRIENDS WHO WOULD VOLUNTEER IN 2401 01:52:07,760 --> 01:52:10,480 AN INSTANT TO BE PART OF THE 2402 01:52:10,480 --> 01:52:12,240 FIRST HUMAN EXPEDITION TO MARS 2403 01:52:12,240 --> 01:52:14,280 EVEN IF IT WERE CERTAIN THEY 2404 01:52:14,280 --> 01:52:16,600 WOULD NEVER COME BACK. AS ONE OF 2405 01:52:16,600 --> 01:52:19,280 MY FRIENDS SAID, IT'S MARS MAN. 2406 01:52:19,280 --> 01:52:21,080 NOW, I'M -- I THINK I WOULD 2407 01:52:21,080 --> 01:52:22,520 RATHER SIT IN MY OFFICE AND HAVE 2408 01:52:22,520 --> 01:52:25,200 A CUP OF COFFEE AND WATCH THAT 2409 01:52:25,200 --> 01:52:27,640 FROM A DISTANCE. BUT I THINK 2410 01:52:27,640 --> 01:52:31,080 THERE IS ACTUALLY A PRACTICAL 2411 01:52:31,080 --> 01:52:35,520 QUESTION IN THAT TO BE HONEST, I 2412 01:52:35,520 --> 01:52:39,080 THINK THE MAJOR REASON TO HAVE 2413 01:52:39,080 --> 01:52:44,600 HUMAN FOOTPRINTS ON MARS IS KIND 2414 01:52:44,600 --> 01:52:46,240 OF A SOLAR SYSTEM MANIFEST 2415 01:52:46,240 --> 01:52:47,640 DESTINY TO SAY WE HAVE DONE IT 2416 01:52:47,640 --> 01:52:50,880 AND CAN PUT THE FLAG IN THERE. 2417 01:52:50,880 --> 01:52:52,440 BECAUSE A, IF WE REALLY START 2418 01:52:52,440 --> 01:52:58,120 WORKING ON THIS, VERY HARD 2419 01:52:58,120 --> 01:53:00,400 TODAY, IT WOULD BE 20 YEARS 2420 01:53:00,400 --> 01:53:02,200 BEFORE A HUMAN WOULD SET FOOT ON 2421 01:53:02,200 --> 01:53:04,360 MARS AND THERE WOULDN'T BE MUCH 2422 01:53:04,360 --> 01:53:06,040 CHANGE FROM YOUR TRILLION DOLLAR 2423 01:53:06,040 --> 01:53:12,280 BILL. WITHIN THAT 20 YEARS THE 2424 01:53:12,280 --> 01:53:15,640 SOPHISTICATION OF ROBOTIC 2425 01:53:15,640 --> 01:53:18,680 INSTRUMENTS WILL BE SUCH THAT I 2426 01:53:18,680 --> 01:53:23,880 HI THE SCIENTIFIC REASONS TO PUT 2427 01:53:23,880 --> 01:53:25,960 A HUMAN ON MARS WILL BE MUCH 2428 01:53:25,960 --> 01:53:30,720 DIMINISHED AND IT HAS TO BE THIS 2429 01:53:30,720 --> 01:53:32,280 EXPLORATION FOR EXPLORATIONS 2430 01:53:32,280 --> 01:53:33,760 SAKE. HAVING SAID THAT, IT IS 2431 01:53:33,760 --> 01:53:35,920 WORTH RECOUNTING A STORY FROM 2432 01:53:35,920 --> 01:53:37,960 WHEN WE WERE FIRST DOING 2433 01:53:37,960 --> 01:53:43,120 PRACTICE MISSIONS FOR THE MARS 2434 01:53:43,120 --> 01:53:46,720 ROVER YEARS AGO AND WE HAD MOCK 2435 01:53:46,720 --> 01:53:50,080 ROVERS IN DEATH VALLEY AND STEVE 2436 01:53:50,080 --> 01:53:53,080 SQUIRE THE CHIEF SCIENTIST AND I 2437 01:53:53,080 --> 01:53:54,920 WERE ON WALK ONE DAY, I LOOKED 2438 01:53:54,920 --> 01:53:56,920 AT A ROCK PICKED IT UP AND 2439 01:53:56,920 --> 01:53:59,240 WHACKED IT WITH MY GEOLOGIC 2440 01:53:59,240 --> 01:54:00,600 HAMMER, TOOK LOOK AT IT THROUGH 2441 01:54:00,600 --> 01:54:03,560 IT AWAY. WHEN I CAME BACK STEVE 2442 01:54:03,560 --> 01:54:06,760 HAD HIS STOPWATCH OUT AND HE 2443 01:54:06,760 --> 01:54:08,960 SAID THAT TOOK YOU TWO MINUTES, 2444 01:54:08,960 --> 01:54:10,800 ON MARS THAT WOULD TAKE YOU A 2445 01:54:10,800 --> 01:54:14,880 WEEK. AND THERE IS THAT SENSE OF 2446 01:54:14,880 --> 01:54:19,400 REAL TIME INTERPRETATION THAT 2447 01:54:19,400 --> 01:54:23,040 HUMANS COULD DO. BUT AGAIN, I 2448 01:54:23,040 --> 01:54:26,640 THINK THAT THE DIFFERENCE 2449 01:54:26,640 --> 01:54:30,280 BETWEEN HUMAN AND ROBOTIC 2450 01:54:30,280 --> 01:54:33,160 INVESTIGATIONS IN TERMS OF 2451 01:54:33,160 --> 01:54:35,680 ACTUAL TIME, IS DIMINISHED 2452 01:54:35,680 --> 01:54:37,440 THROUGH TIME, AND WITH THE 2453 01:54:37,440 --> 01:54:38,280 ROBOTS GETTING BETTER AND BETTER 2454 01:54:38,280 --> 01:54:42,200 AT DOING THE THINGS THAT WE DO. 2455 01:54:42,200 --> 01:54:43,360 AND SURE THAT THERE ARE 2456 01:54:43,360 --> 01:54:45,720 ENGINEERS WORKING HOW ARTIFICIAL 2457 01:54:45,720 --> 01:54:46,760 INTELLIGENCE CAN FURTHER ALLOW 2458 01:54:46,760 --> 01:54:50,280 DECISION MAKING BY ROBOTS. SO WE 2459 01:54:50,280 --> 01:54:51,760 WILL SEE. I DON'T KNOW WHAT THE 2460 01:54:51,760 --> 01:54:54,520 FUTURE BRINGS. I'M FINE WITH 2461 01:54:54,520 --> 01:54:57,840 YOGI BERRA, I THINK YOU ARE 2462 01:54:57,840 --> 01:55:00,960 RIGHT. IF BERRA EVER READ NEIL 2463 01:55:00,960 --> 01:55:01,160 SPORE. 2464 01:55:01,160 --> 01:55:03,000 >> WE ONLY HAVE TIME FOR TWO 2465 01:55:03,000 --> 01:55:04,960 QUESTIONS. I HAVE ONE LAST ONE 2466 01:55:04,960 --> 01:55:07,960 TO ASK YOU. SO I'M GOING TO SAVE 2467 01:55:07,960 --> 01:55:13,240 THAT BUT QUICK QUESTION. MOST 2468 01:55:13,240 --> 01:55:14,600 WRITING ABOUT LIFE ON EARTH 2469 01:55:14,600 --> 01:55:16,440 BEGIN BUSINESS TALKING ABOUT THE 2470 01:55:16,440 --> 01:55:18,560 FAMOUS MIRROR EXPERIMENT IN THE 2471 01:55:18,560 --> 01:55:23,200 1950s. IS THAT EXPERIMENT EVER 2472 01:55:23,200 --> 01:55:25,560 BEEN REPEATED, NOT IN TERMS OF 2473 01:55:25,560 --> 01:55:28,920 ITS VALIDITY BUT IN TERMS OF 2474 01:55:28,920 --> 01:55:31,760 EXPANDING IT, OF WHAT COMES 2475 01:55:31,760 --> 01:55:36,880 NEXT. HAS THAT OR IS THAT JUST 2476 01:55:36,880 --> 01:55:38,880 MAYBE THERE'S NO FUNDING FOR, I 2477 01:55:38,880 --> 01:55:40,040 DON'T KNOW, WHAT IS THE 2478 01:55:40,040 --> 01:55:42,040 SITUATION FOR THAT? 2479 01:55:42,040 --> 01:55:46,840 >> THERE IS ACTUALLY SMALL 2480 01:55:46,840 --> 01:55:52,360 VIBRANT COMMUNITY PEOPLE WHO DO 2481 01:55:52,360 --> 01:55:53,600 EXPERIMENTS VERSUS STANLEY 2482 01:55:53,600 --> 01:55:56,240 MILLER THEMSELVES, IN YEARS 2483 01:55:56,240 --> 01:55:59,600 FOLLOWING THE MILLER EXPERIMENT 2484 01:55:59,600 --> 01:56:04,400 DID ACTUALLY VARY THE RECIPE FOR 2485 01:56:04,400 --> 01:56:06,440 THE EXPERIMENT, SAW HOW YIELDS 2486 01:56:06,440 --> 01:56:07,880 AND THINGS LIKE THAT VARIED SO 2487 01:56:07,880 --> 01:56:09,880 STANLEY DID A LOT OF WORK BUT 2488 01:56:09,880 --> 01:56:13,080 MANY OTHER PEOPLE HAVE DONE 2489 01:56:13,080 --> 01:56:15,560 ENOUGH WORK THAT AT THIS POINTS 2490 01:56:15,560 --> 01:56:17,960 I THINK MOST PEOPLE ARE CONTENT 2491 01:56:17,960 --> 01:56:20,600 TO THINK BIOLOGICALLY IMPORTANT 2492 01:56:20,600 --> 01:56:22,920 MONOMERS CAN BE MADE BY PHYSICAL 2493 01:56:22,920 --> 01:56:25,880 PROCESSES. THERE IS ALSO A LOT 2494 01:56:25,880 --> 01:56:30,160 OF WORK ON TRYING TO CONDENSE 2495 01:56:30,160 --> 01:56:34,760 THOSE MONOMERS SO YOU CAN MAKE 2496 01:56:34,760 --> 01:56:37,760 FOLLOWERS AND THAT HAS CERTAIN 2497 01:56:37,760 --> 01:56:39,680 CONSTRAINTS BUT REASONABLY 2498 01:56:39,680 --> 01:56:42,560 SUCCESSFUL PEOPLE LIKE LESLIE 2499 01:56:42,560 --> 01:56:45,360 DID INTERESTING WORK ON 2500 01:56:45,360 --> 01:56:52,120 REPLICATING NUCLEIC ACID MON 2501 01:56:52,120 --> 01:56:53,320 MORES HOG GOMERICALLY. THERE IS 2502 01:56:53,320 --> 01:56:55,240 A -- OLIGOMERICALLY. THERE'S A 2503 01:56:55,240 --> 01:56:57,400 FAIR AMOUNT OF WORK ON THAT. AND 2504 01:56:57,400 --> 01:56:59,400 IT ALL LEADS IN THE DIRECTION OF 2505 01:56:59,400 --> 01:57:02,400 PLAUSIBILITY. 2506 01:57:02,400 --> 01:57:05,280 >> PERMIT ME TO ASK THE LAST 2507 01:57:05,280 --> 01:57:07,480 QUESTIQUESTION. YOU COMMENTED AT 2508 01:57:07,480 --> 01:57:10,040 THE CHANGES IN ATTITUDE AND 2509 01:57:10,040 --> 01:57:13,640 UNDERSTANDING OF THE PAST 50 2510 01:57:13,640 --> 01:57:19,360 YEARS. NOW THE QUESTION IS, IN 2511 01:57:19,360 --> 01:57:24,360 THE NEXT 50 YEARS WHAT DO YOU 2512 01:57:24,360 --> 01:57:27,640 THINK OUR GRANDCHILDREN WILL 2513 01:57:27,640 --> 01:57:34,040 KNOW ABOUT THE ORIGIN OF LIFE? 2514 01:57:34,040 --> 01:57:36,400 >> AGAIN, ONE CAN ONLY 2515 01:57:36,400 --> 01:57:38,080 SPECULATE. I SHOULD SAY THAT 2516 01:57:38,080 --> 01:57:40,720 ALTHOUGH SOME WAYS MILLER YUI 2517 01:57:40,720 --> 01:57:43,720 AND THE AGE OF PLANETARY 2518 01:57:43,720 --> 01:57:46,240 EXPLORATION THINKING ABOUT 2519 01:57:46,240 --> 01:57:49,640 ORIGIN OF LIFE OR LIFE TO 2520 01:57:49,640 --> 01:57:51,560 UNIVERSE, THE LAST 70, 80ERS 2521 01:57:51,560 --> 01:57:55,040 YEW, IF YOU GO BACK TO PARADISE 2522 01:57:55,040 --> 01:57:59,320 LOST,S JOHN MILTEN HAS A 2523 01:57:59,320 --> 01:58:00,880 QUATRAINE ABOUT MOUNTAINS 2524 01:58:00,880 --> 01:58:02,720 VALLEYS RIVERS AN LIFE ON OTHER 2525 01:58:02,720 --> 01:58:07,680 PLANETS BECAUSE G A ALELEO 2526 01:58:07,680 --> 01:58:09,880 LANDED IN MILTON CORRESPONDED 2527 01:58:09,880 --> 01:58:13,000 WITH Q GALILEO. SO THE 2528 01:58:13,000 --> 01:58:14,640 EXPECTATION IN THOSE DAY, THERE 2529 01:58:14,640 --> 01:58:15,760 ARE OTHER PLANETS OUT THERE, 2530 01:58:15,760 --> 01:58:19,240 THEY ARE LIKE US, THEY PROBABLY 2531 01:58:19,240 --> 01:58:22,160 HAVE LIFE, WHAT IS THE BIG DEAL? 2532 01:58:22,160 --> 01:58:23,960 IT WAS ONLY IN THE 19TH CENTURY 2533 01:58:23,960 --> 01:58:27,400 LOOKING MORE CLOSELY AND SAW 2534 01:58:27,400 --> 01:58:31,200 THAT MARS WAS A PRETTY DECEMBER 2535 01:58:31,200 --> 01:58:34,160 LATE PLACE THAT ENTHUSIASM AT 2536 01:58:34,160 --> 01:58:37,360 LEAST FOR LIFE BEYOND THE EARTH 2537 01:58:37,360 --> 01:58:41,200 DECLINED, BUT NOW WITH THE 2538 01:58:41,200 --> 01:58:43,320 CURRENT AGE OF EXPLORATION, IT'S 2539 01:58:43,320 --> 01:58:44,800 COME BACK AGAIN SO I IMAGINE 2540 01:58:44,800 --> 01:58:47,960 THAT MANY OF THE QUESTIONS WHERE 2541 01:58:47,960 --> 01:58:50,320 I HAD TO TRUTHFULLY ANSWER AND 2542 01:58:50,320 --> 01:58:54,400 SAY WE DON'T KNOW, WILL BE 2543 01:58:54,400 --> 01:58:58,080 CLOSER TO CLOSER TO DEFINITIVE 2544 01:58:58,080 --> 01:58:59,120 EXPLANATION 50 YEARS FROM NOW, 2545 01:58:59,120 --> 01:59:01,720 WE WILL KNOW WHETHER OR NOT 2546 01:59:01,720 --> 01:59:04,440 THERE'S BEEN LIFE IN ANOTHER 2547 01:59:04,440 --> 01:59:06,480 SOLAR SYSTEM. WE MAY OR MAY NOT 2548 01:59:06,480 --> 01:59:07,520 KNOW WHETHER THERE'S INTELLIGENT 2549 01:59:07,520 --> 01:59:09,640 LIFE OUT THERE. BECAUSE IT MAY 2550 01:59:09,640 --> 01:59:11,560 OR MY NOT BE OUT THERE. I THINK 2551 01:59:11,560 --> 01:59:14,080 WE WILL KNOW A LOT MORE ABOUT 2552 01:59:14,080 --> 01:59:18,000 THE PROCESSES THAT NOT ONLY GIVE 2553 01:59:18,000 --> 01:59:20,440 RISE TO INFORMATION BUT ALSO 2554 01:59:20,440 --> 01:59:23,080 GIVE RISE TO PROTEINS AND 2555 01:59:23,080 --> 01:59:28,480 FUNCTION. AND I'M ACTUALLY 2556 01:59:28,480 --> 01:59:30,080 FAIRLY CONFIDENTNA WE WILL HAVE 2557 01:59:30,080 --> 01:59:33,280 A REASONABLE UNDERSTANDING OF 2558 01:59:33,280 --> 01:59:37,200 HOW THOSE TWO TYPES OF SYSTEMS 2559 01:59:37,200 --> 01:59:40,640 INTEGRATE. THERE'S ALREADY SOME 2560 01:59:40,640 --> 01:59:41,480 INTERESTING WORK WHERE PEOPLE 2561 01:59:41,480 --> 01:59:45,400 ARE STARTING TO LOOK AT, NOT SO 2562 01:59:45,400 --> 01:59:46,800 MUCH AT THE PART OF ENZYME BUT 2563 01:59:46,800 --> 01:59:51,440 THE CO-FACTORS. AND THAT MAY 2564 01:59:51,440 --> 01:59:55,040 ACTUALLY OPEN UP A INTERESTING 2565 01:59:55,040 --> 01:59:55,920 BRIDGE BETWEEN THESE TWO 2566 01:59:55,920 --> 01:59:57,640 DIFFERENT WAYS OF THINKING ABOUT 2567 01:59:57,640 --> 01:59:59,920 THE ORIGIN OF LIFE. I WON'T BE 2568 01:59:59,920 --> 02:00:01,760 HERE SO WE WILL SE SEE. 2569 02:00:01,760 --> 02:00:03,600 >> WE SHOULD ALL BE AROUND THE 2570 02:00:03,600 --> 02:00:06,440 NEXT 50 YEARS TO FIND OUT. 2571 02:00:06,440 --> 02:00:09,200 THAT'S PROBABLY -- I 2572 02:00:09,200 --> 02:00:10,000 (OVERLAPPING SPEAKERS) 2573 02:00:10,000 --> 02:00:12,320 >> AT LEAST IN MY MIND TIES 2574 02:00:12,320 --> 02:00:15,360 WHICH YOU ARE TALKING ABOUT IN 2575 02:00:15,360 --> 02:00:17,000 WITH RESPECT TO MEDICINE AND 2576 02:00:17,000 --> 02:00:19,200 HEALTH AND ALL, THAT IS OF 2577 02:00:19,200 --> 02:00:23,560 COURSE, THIS HUMAN MICROBIOME 2578 02:00:23,560 --> 02:00:28,920 WHICH IS HOME TO BACTERIA 2579 02:00:28,920 --> 02:00:31,680 ARCHAEA VIRUSES FUN GUY, 2580 02:00:31,680 --> 02:00:34,040 PARASITES, I GUESS IT IS A BIG 2581 02:00:34,040 --> 02:00:37,280 STRETCH TO PUT THAT IN TO 2582 02:00:37,280 --> 02:00:39,560 GEOLOGIC TERMS BUT MAYBE THERE 2583 02:00:39,560 --> 02:00:42,720 ARE SOME RELATIONSHIPS IN TERMS 2584 02:00:42,720 --> 02:00:47,240 OF WHAT YOU LEARN ABOUT HOW 2585 02:00:47,240 --> 02:00:52,560 BACTERIA REACTING WITH GEOLOGIC 2586 02:00:52,560 --> 02:00:53,600 FEATURES CHANGE OR HAS SOMETHING 2587 02:00:53,600 --> 02:00:54,880 TO DO WITH THE ELUTION OF LIFE 2588 02:00:54,880 --> 02:01:01,360 AND CHANGE IN FORM. SO WE ARE 2589 02:01:01,360 --> 02:01:04,440 NOT ONLY OUT OF THAT REALM. 2590 02:01:04,440 --> 02:01:06,640 >> NOT AT ALL. 2591 02:01:06,640 --> 02:01:10,120 >> SO LISTEN, I'M SURE THERE ARE 2592 02:01:10,120 --> 02:01:11,640 HUNDREDS AND HUNDREDS, I DON'T 2593 02:01:11,640 --> 02:01:13,640 KNOW THOUSANDS OF PEOPLE WHO 2594 02:01:13,640 --> 02:01:17,160 HAVE WATCHED YOUR PRESENTATION 2595 02:01:17,160 --> 02:01:19,640 TODAY. HALF OF THEM AND ALL OF 2596 02:01:19,640 --> 02:01:21,240 ON BEHALF OF THEM AND ALL OF US, 2597 02:01:21,240 --> 02:01:23,360 WE REALLY THANK Y THANK YOU. THS 2598 02:01:23,360 --> 02:01:28,120 BEEN A VERY EXCITING AND 2599 02:01:28,120 --> 02:01:29,680 PROVOCATIVE, I THINK IT IS 2600 02:01:29,680 --> 02:01:34,040 ANOTHER EXAMPLE THAT BRIDGING 2601 02:01:34,040 --> 02:01:36,680 FROM CLASSICAL CLINICAL MEDICINE 2602 02:01:36,680 --> 02:01:38,840 IN TO DISCIPLINES SUCH AS YOURS, 2603 02:01:38,840 --> 02:01:41,880 IS NOT AS FARFETCHED AS ONE 2604 02:01:41,880 --> 02:01:44,240 MAKES BECAUSE WE ARE ALL 2605 02:01:44,240 --> 02:01:45,640 CONFRONTING THE SAME BIG 2606 02:01:45,640 --> 02:01:47,480 BIOLOGICAL QUESTIONS ABOUT LIFE, 2607 02:01:47,480 --> 02:01:50,400 ABOUT EVOLUTION, ABOUT 2608 02:01:50,400 --> 02:01:53,520 ADAPTATION. THESE ARE THINGS 2609 02:01:53,520 --> 02:01:55,560 IMPORTANT TO KNOW. SO THANK YOU, 2610 02:01:55,560 --> 02:01:58,160 THANK YOU VERY, VERY MUCH. WE 2611 02:01:58,160 --> 02:02:00,360 HOPE SOME DAY YOU WILL COME 2612 02:02:00,360 --> 02:02:03,400 VISIT THE NIH AND IT WOULD BE A 2613 02:02:03,400 --> 02:02:04,880 PLEASURE. 2614 02:02:04,880 --> 02:02:05,520 >> THANK YOU AGAIN FOR INVITING 2615 02:02:05,520 --> 02:02:06,000 ME AND FOR EVERYBODY THAT ASKED 2616 02:02:06,000 --> 02:02:06,440 QUESTIONS. THIS WAS ACTUALLY A 2617 02:02:06,440 --> 00:00:00,000 LOT OF FUN. I APPRECIATE IT.