1 00:00:00,160 --> 00:00:14,470 [Music] 2 00:00:19,189 --> 00:00:17,029 okay thank you everybody yeah it's an 3 00:00:20,779 --> 00:00:19,199 amazing room I promise you that at 25 4 00:00:24,500 --> 00:00:20,789 minutes I will turn yellow and then at 5 00:00:26,509 --> 00:00:24,510 30 minutes I will turn red since the 6 00:00:28,160 --> 00:00:26,519 topic of the symposium was expanding 7 00:00:31,030 --> 00:00:28,170 views on the emergence of the biosphere 8 00:00:33,530 --> 00:00:31,040 I thought I would talk about plurality 9 00:00:35,690 --> 00:00:33,540 for the origin of life we have many 10 00:00:37,700 --> 00:00:35,700 bodies of evidence all complicated that 11 00:00:39,590 --> 00:00:37,710 are relevant to understand and it's 12 00:00:41,270 --> 00:00:39,600 possible to put together many possible 13 00:00:42,860 --> 00:00:41,280 scenarios for emergence that either 14 00:00:45,260 --> 00:00:42,870 emphasize different bodies of evidence 15 00:00:47,569 --> 00:00:45,270 or that interpret the same evidence in 16 00:00:51,139 --> 00:00:47,579 different ways so then the question is 17 00:00:53,479 --> 00:00:51,149 how do we want to get beyond the 18 00:00:55,400 --> 00:00:53,489 spinning of scenarios to a notion of 19 00:00:59,000 --> 00:00:55,410 cause and how can we learn to think 20 00:01:00,560 --> 00:00:59,010 systematically about these problems so a 21 00:01:02,479 --> 00:01:00,570 lot of times when people want to 22 00:01:04,700 --> 00:01:02,489 organize a diverse body of evidence of 23 00:01:05,990 --> 00:01:04,710 starting point is defination so I 24 00:01:07,940 --> 00:01:06,000 thought I would open with a good strong 25 00:01:09,980 --> 00:01:07,950 statement by Jack szostak about how well 26 00:01:12,050 --> 00:01:09,990 that seems to be working in his opinion 27 00:01:14,359 --> 00:01:12,060 for the origin of life Jack says 28 00:01:16,880 --> 00:01:14,369 attempts to define life do not help to 29 00:01:19,780 --> 00:01:16,890 understand the origin of life no on him 30 00:01:22,520 --> 00:01:19,790 no ambiguity there so his argument is 31 00:01:25,249 --> 00:01:22,530 you know as with all things from Shostak 32 00:01:28,910 --> 00:01:25,259 deeply empirical and very concerned with 33 00:01:30,710 --> 00:01:28,920 getting the details right he says that 34 00:01:32,179 --> 00:01:30,720 there's a huge number of transitions 35 00:01:34,370 --> 00:01:32,189 that are qualitatively of different 36 00:01:36,920 --> 00:01:34,380 kinds that make up the emergence of a 37 00:01:38,990 --> 00:01:36,930 biosphere and for people to artificially 38 00:01:41,719 --> 00:01:39,000 put a dichotomy in that and say that is 39 00:01:45,590 --> 00:01:41,729 not life this is that was before life 40 00:01:47,450 --> 00:01:45,600 this is is actually not faithful to the 41 00:01:49,310 --> 00:01:47,460 nature of the evidence and what we 42 00:01:50,840 --> 00:01:49,320 should do instead is just do careful 43 00:01:52,940 --> 00:01:50,850 science about the collection of diverse 44 00:01:56,060 --> 00:01:52,950 problems that we have to deal with as 45 00:01:58,490 --> 00:01:56,070 far as that goes absolutely and it's an 46 00:02:00,289 --> 00:01:58,500 important voice of discipline in what 47 00:02:02,480 --> 00:02:00,299 can sometimes be an undisciplined field 48 00:02:04,819 --> 00:02:02,490 and yet on the other hand the notion 49 00:02:07,130 --> 00:02:04,829 since antiquity that there is a unity of 50 00:02:09,199 --> 00:02:07,140 living things in the world is still 51 00:02:11,839 --> 00:02:09,209 correct and it is still scientifically 52 00:02:13,730 --> 00:02:11,849 relevant and the forest of life is more 53 00:02:16,030 --> 00:02:13,740 than the arbitrary sequence of tree 54 00:02:18,470 --> 00:02:16,040 that we happen to have chosen to study 55 00:02:19,730 --> 00:02:18,480 and that's an it's particularly 56 00:02:22,430 --> 00:02:19,740 important if we want to learn how to 57 00:02:24,650 --> 00:02:22,440 reason in the absence of evidence which 58 00:02:26,660 --> 00:02:24,660 is important because what we don't know 59 00:02:29,150 --> 00:02:26,670 that's necessary is more important or is 60 00:02:30,620 --> 00:02:29,160 larger than what we do so the question 61 00:02:32,930 --> 00:02:30,630 is how do we understand both the 62 00:02:35,390 --> 00:02:32,940 multiplicity and the unity that's sort 63 00:02:38,060 --> 00:02:35,400 of this notion of a pluribus unum out of 64 00:02:40,460 --> 00:02:38,070 many things that remain many when do 65 00:02:45,860 --> 00:02:40,470 they become an interdependent one while 66 00:02:47,930 --> 00:02:45,870 not losing their men enos so here are 67 00:02:49,640 --> 00:02:47,940 two examples of trying to create 68 00:02:50,960 --> 00:02:49,650 definitions of life that come from 69 00:02:54,200 --> 00:02:50,970 different perspectives and emphasize 70 00:02:55,630 --> 00:02:54,210 different things one is often cited as 71 00:02:58,040 --> 00:02:55,640 the working definition of NASA 72 00:03:00,880 --> 00:02:58,050 attributed to a working group that Gerry 73 00:03:02,660 --> 00:03:00,890 Joyce was in or chair of a 74 00:03:05,330 --> 00:03:02,670 self-maintaining chemical system capable 75 00:03:07,040 --> 00:03:05,340 of Darwinian evolution good features of 76 00:03:08,900 --> 00:03:07,050 this definition are it acknowledges the 77 00:03:11,090 --> 00:03:08,910 central role of chemistry though without 78 00:03:13,850 --> 00:03:11,100 necessarily explaining why it should be 79 00:03:16,190 --> 00:03:13,860 central the negative part is that it 80 00:03:18,740 --> 00:03:16,200 entails a lot of very complex concepts 81 00:03:20,750 --> 00:03:18,750 in that word Darwinian evolution and in 82 00:03:22,280 --> 00:03:20,760 my opinion others could disagree it 83 00:03:24,740 --> 00:03:22,290 under emphasizes how hard it is to 84 00:03:26,750 --> 00:03:24,750 explain why those concept concepts 85 00:03:29,750 --> 00:03:26,760 should be necessary to explain the 86 00:03:32,120 --> 00:03:29,760 structure of real matter Pete hood one 87 00:03:34,010 --> 00:03:32,130 of the founding PI's of LC takes a 88 00:03:35,600 --> 00:03:34,020 completely different approach on this he 89 00:03:37,250 --> 00:03:35,610 wants to say that the origin of life is 90 00:03:39,320 --> 00:03:37,260 the emergence the spontaneous of 91 00:03:41,900 --> 00:03:39,330 emergent emergence of autonomous agents 92 00:03:44,750 --> 00:03:41,910 in a complex system the plus side of 93 00:03:46,520 --> 00:03:44,760 that is that it gives specific names to 94 00:03:48,260 --> 00:03:46,530 a lot of aspects of architecture that 95 00:03:50,810 --> 00:03:48,270 are fundamental to the biosphere and 96 00:03:52,490 --> 00:03:50,820 that precede evolution so you need them 97 00:03:55,030 --> 00:03:52,500 to talk about where the Darwinian world 98 00:03:57,320 --> 00:03:55,040 enters and some of them are importantly 99 00:03:59,450 --> 00:03:57,330 independently of it and yet still 100 00:04:01,250 --> 00:03:59,460 fundamental to the nature of life the 101 00:04:03,440 --> 00:04:01,260 negative side is that it's about 102 00:04:05,330 --> 00:04:03,450 high-level structure and it doesn't 103 00:04:07,010 --> 00:04:05,340 actually give a place to the conceptual 104 00:04:09,110 --> 00:04:07,020 role of chemistry so you could argue 105 00:04:11,350 --> 00:04:09,120 that these are two complementary views 106 00:04:14,510 --> 00:04:11,360 of the element elephant that cover 107 00:04:17,449 --> 00:04:14,520 different things now when you put up a 108 00:04:18,349 --> 00:04:17,459 definition like this you can ask we try 109 00:04:19,910 --> 00:04:18,359 to find things 110 00:04:21,950 --> 00:04:19,920 according to attributes that other 111 00:04:24,260 --> 00:04:21,960 things don't share but if we want a 112 00:04:26,050 --> 00:04:24,270 notion of cause we need to get beyond 113 00:04:28,240 --> 00:04:26,060 just attributes to essence 114 00:04:31,030 --> 00:04:28,250 things from which other things follow 115 00:04:32,860 --> 00:04:31,040 and so we asked in either of these 116 00:04:34,629 --> 00:04:32,870 definitions are we just looking at 117 00:04:36,700 --> 00:04:34,639 attributes that are useful to 118 00:04:38,710 --> 00:04:36,710 distinguish life or are we looking at 119 00:04:41,530 --> 00:04:38,720 essences that are good starting points 120 00:04:43,300 --> 00:04:41,540 in a theory of cause so one way people 121 00:04:45,340 --> 00:04:43,310 try to get at what is a starting point 122 00:04:47,500 --> 00:04:45,350 in a complicated world is to make 123 00:04:49,659 --> 00:04:47,510 dichotomies to take things that they 124 00:04:51,400 --> 00:04:49,669 think are alternatives and say can we 125 00:04:52,990 --> 00:04:51,410 cut one of them out and say that the 126 00:04:54,940 --> 00:04:53,000 essence of life were of the origin of 127 00:04:57,930 --> 00:04:54,950 life is found in the other so I'll give 128 00:05:00,250 --> 00:04:57,940 you three dichotomies and I'll give you 129 00:05:02,260 --> 00:05:00,260 what was in the abstract to this talk 130 00:05:03,760 --> 00:05:02,270 the argument that both sides seem to be 131 00:05:07,150 --> 00:05:03,770 fundamental and the dichotomy is not a 132 00:05:09,700 --> 00:05:07,160 cut at all so geochemical continuity or 133 00:05:11,320 --> 00:05:09,710 biochemical innovation is life 134 00:05:13,210 --> 00:05:11,330 fundamentally a chemical system or 135 00:05:16,180 --> 00:05:13,220 fundamentally an informational system 136 00:05:18,130 --> 00:05:16,190 and what should we think of as the unit 137 00:05:21,370 --> 00:05:18,140 of memory and persistence in the system 138 00:05:23,680 --> 00:05:21,380 organism ecosystem something else so 139 00:05:25,719 --> 00:05:23,690 first question is it an extension of 140 00:05:28,390 --> 00:05:25,729 geochemistry or an innovative departure 141 00:05:30,670 --> 00:05:28,400 this is a from a paper by George Cooper 142 00:05:32,409 --> 00:05:30,680 looking at the volatile content of 143 00:05:34,690 --> 00:05:32,419 organics and carbonaceous meteorites 144 00:05:37,480 --> 00:05:34,700 Cooper estimates that from the sample 145 00:05:39,159 --> 00:05:37,490 there are at least 50,000 probably 146 00:05:41,890 --> 00:05:39,169 correcting four sample blind spots 147 00:05:44,380 --> 00:05:41,900 closer to a half a million just volatile 148 00:05:46,810 --> 00:05:44,390 compounds in characteristic carbonaceous 149 00:05:49,600 --> 00:05:46,820 meteorite samples now if you look at the 150 00:05:51,100 --> 00:05:49,610 GC spectra of these you notice first of 151 00:05:53,020 --> 00:05:51,110 all that they are not uniform they're 152 00:05:54,940 --> 00:05:53,030 not mud and second that they have a 153 00:05:57,550 --> 00:05:54,950 significant overlap with compounds that 154 00:05:59,770 --> 00:05:57,560 are very central to actual biochemistry 155 00:06:01,750 --> 00:05:59,780 on the other hand a half a million 156 00:06:03,159 --> 00:06:01,760 compounds is considerably larger and 157 00:06:05,740 --> 00:06:03,169 considerably less discipline than 158 00:06:07,570 --> 00:06:05,750 biochemistry now Cooper I apologize for 159 00:06:09,279 --> 00:06:07,580 the rendering of this slide puts 160 00:06:10,930 --> 00:06:09,289 together a system in which he would say 161 00:06:13,060 --> 00:06:10,940 that pyruvate is the crucial non 162 00:06:16,570 --> 00:06:13,070 equilibrium compound that can actually 163 00:06:18,130 --> 00:06:16,580 be driving all of this so I should have 164 00:06:20,200 --> 00:06:18,140 mentioned at the beginning the question 165 00:06:22,510 --> 00:06:20,210 of extending geochemistry or innovating 166 00:06:24,370 --> 00:06:22,520 away from it is sort of the main point 167 00:06:26,740 --> 00:06:24,380 that distinguishes people who want early 168 00:06:28,420 --> 00:06:26,750 metabolism to be a foundation versus 169 00:06:31,690 --> 00:06:28,430 people who want some sort of RNA 170 00:06:34,149 --> 00:06:31,700 mediated central dogma type control to 171 00:06:35,710 --> 00:06:34,159 be the start so this is meteoritic 172 00:06:38,589 --> 00:06:35,720 carbon not so different from 173 00:06:39,380 --> 00:06:38,599 biochemistry contrast that with this 174 00:06:41,210 --> 00:06:39,390 this is a paper 175 00:06:43,460 --> 00:06:41,220 by Vijay Srinivasan and Harold Moore 176 00:06:45,580 --> 00:06:43,470 wits from a few years ago starting from 177 00:06:47,420 --> 00:06:45,590 the sequence genomes of aquifer Kaylee's 178 00:06:50,030 --> 00:06:47,430 reductive citric acid cycle 179 00:06:52,550 --> 00:06:50,040 autotrophs and saying can we distill 180 00:06:54,830 --> 00:06:52,560 from these complete genomes and then 181 00:06:57,260 --> 00:06:54,840 comparative analysis of alternatives in 182 00:06:59,390 --> 00:06:57,270 enzyme databases a kind of minimal 183 00:07:02,300 --> 00:06:59,400 metabolism that is both universal across 184 00:07:04,670 --> 00:07:02,310 the biosphere and also sufficient to 185 00:07:07,400 --> 00:07:04,680 create any living system and they say 186 00:07:10,130 --> 00:07:07,410 you can cut this down to about 125 187 00:07:11,810 --> 00:07:10,140 monomers and small metabolites and out 188 00:07:13,790 --> 00:07:11,820 of this you build everything in the 189 00:07:17,480 --> 00:07:13,800 world so we're down from a half a 190 00:07:19,130 --> 00:07:17,490 million to 125 so this says that the 191 00:07:22,010 --> 00:07:19,140 distinction in biochemistry that is 192 00:07:24,320 --> 00:07:22,020 conservative of geochemistry consists 193 00:07:26,000 --> 00:07:24,330 mostly of pruning but that accounts from 194 00:07:28,250 --> 00:07:26,010 maybe a third of the compounds in this 195 00:07:32,210 --> 00:07:28,260 diagram and the other two-thirds are 196 00:07:33,860 --> 00:07:32,220 innovation so so far both and of course 197 00:07:35,630 --> 00:07:33,870 the attempt to make a dichotomy gets 198 00:07:38,630 --> 00:07:35,640 worse when you realize that the 199 00:07:40,580 --> 00:07:38,640 trajectory of geology once a biosphere 200 00:07:42,860 --> 00:07:40,590 has emerged it can no longer be 201 00:07:45,140 --> 00:07:42,870 understood without the biosphere so for 202 00:07:48,350 --> 00:07:45,150 instance we have Bob Hazen's analysis 203 00:07:50,120 --> 00:07:48,360 both in the empirical record and then by 204 00:07:52,100 --> 00:07:50,130 looking at mineral formation conditions 205 00:07:54,020 --> 00:07:52,110 of the fact that the mineral inventory 206 00:07:56,690 --> 00:07:54,030 on earth has changed cattle 207 00:07:58,580 --> 00:07:56,700 categorically between the earliest 208 00:08:00,800 --> 00:07:58,590 record in the Archaean into the 209 00:08:03,230 --> 00:08:00,810 Proterozoic this is an index of the 210 00:08:05,510 --> 00:08:03,240 diversity of boron minerals versus time 211 00:08:06,680 --> 00:08:05,520 but bob has similar tables for barium 212 00:08:09,650 --> 00:08:06,690 minerals in a variety of other things 213 00:08:12,020 --> 00:08:09,660 and a lot of this is due to feedbacks 214 00:08:13,610 --> 00:08:12,030 from seeding the environment with oxygen 215 00:08:16,280 --> 00:08:13,620 some of it is due to microbial 216 00:08:19,940 --> 00:08:16,290 precipitation so geology is no longer an 217 00:08:22,340 --> 00:08:19,950 abiotic concept once life exists one can 218 00:08:25,010 --> 00:08:22,350 go even further there's a fascinating 219 00:08:26,990 --> 00:08:25,020 argument I don't know how strong it is 220 00:08:28,700 --> 00:08:27,000 Minik rosen and then two of our guests 221 00:08:31,820 --> 00:08:28,710 last year norm sleep and fluency 222 00:08:34,070 --> 00:08:31,830 elbaradei our authors on this they argue 223 00:08:36,310 --> 00:08:34,080 that something as remarkable as the 224 00:08:39,219 --> 00:08:36,320 innovation of photosynthesis by driving 225 00:08:41,510 --> 00:08:39,229 geochemical cycles through the biosphere 226 00:08:43,610 --> 00:08:41,520 actually change the rate of granite 227 00:08:45,650 --> 00:08:43,620 formation and hence the accretion of 228 00:08:48,410 --> 00:08:45,660 continents and the formation of tectonic 229 00:08:49,790 --> 00:08:48,420 cycles that of course affects the rate 230 00:08:51,860 --> 00:08:49,800 of cooling through the upper mantle 231 00:08:53,780 --> 00:08:51,870 which then has implications for the 232 00:08:55,250 --> 00:08:53,790 maintenance of the geodynamo 233 00:08:58,220 --> 00:08:55,260 and the magnetic field and the 234 00:09:00,710 --> 00:08:58,230 conditions of the atmosphere so the 235 00:09:02,930 --> 00:09:00,720 whole notion of making a dichotomy 236 00:09:04,910 --> 00:09:02,940 between the abiotic earth and the 237 00:09:07,820 --> 00:09:04,920 biosphere looks like it's becoming a 238 00:09:09,860 --> 00:09:07,830 real mess okay how about the second one 239 00:09:12,290 --> 00:09:09,870 is life fundamentally chemical or is it 240 00:09:13,820 --> 00:09:12,300 fundamentally informational a lot of 241 00:09:15,950 --> 00:09:13,830 times when people say informational 242 00:09:18,650 --> 00:09:15,960 they're asking about the combinatorics 243 00:09:20,600 --> 00:09:18,660 of sequences there are a lot of places I 244 00:09:22,190 --> 00:09:20,610 could approach this but let me do one in 245 00:09:24,050 --> 00:09:22,200 particular from the genetic code that 246 00:09:26,540 --> 00:09:24,060 allows me to illustrate the contrast 247 00:09:28,220 --> 00:09:26,550 when we think about the combinatorial 248 00:09:30,530 --> 00:09:28,230 information in the genetic code that 249 00:09:33,050 --> 00:09:30,540 might reflect the action of selection we 250 00:09:34,490 --> 00:09:33,060 think of taking the amino acids as given 251 00:09:36,500 --> 00:09:34,500 that's somebody else's problem and 252 00:09:38,900 --> 00:09:36,510 taking the number of times each one 253 00:09:40,520 --> 00:09:38,910 appears just how many different shuffles 254 00:09:42,860 --> 00:09:40,530 could there be through the adapter 255 00:09:44,870 --> 00:09:42,870 apparatus of the genetic code that would 256 00:09:46,820 --> 00:09:44,880 still function and you can do the 257 00:09:49,910 --> 00:09:46,830 combinatorics and you say okay there's 258 00:09:51,650 --> 00:09:49,920 about 230 bits of information that look 259 00:09:53,540 --> 00:09:51,660 like they were selected to produce this 260 00:09:55,790 --> 00:09:53,550 code out of anything with the same 261 00:09:57,980 --> 00:09:55,800 number of amino acids but what if you 262 00:10:00,560 --> 00:09:57,990 said let's not take the amino acid 263 00:10:02,630 --> 00:10:00,570 inventory as given let's ask out of the 264 00:10:05,120 --> 00:10:02,640 carbonaceous inventory how did that 265 00:10:06,740 --> 00:10:05,130 amino acid inventory get selected now 266 00:10:08,930 --> 00:10:06,750 you might argue that that's a separate 267 00:10:09,440 --> 00:10:08,940 problem of pruning that doesn't belong 268 00:10:11,810 --> 00:10:09,450 here 269 00:10:16,160 --> 00:10:11,820 except that and that's the content of 270 00:10:18,590 --> 00:10:16,170 this paper here the particular way the 271 00:10:22,220 --> 00:10:18,600 amino acid assignments are made in the 272 00:10:24,950 --> 00:10:22,230 genetic code is threw out based on the 273 00:10:27,230 --> 00:10:24,960 biosynthetic sequence of the amino acids 274 00:10:30,230 --> 00:10:27,240 not just their terminal properties but 275 00:10:32,060 --> 00:10:30,240 how they're made so that argues that the 276 00:10:34,280 --> 00:10:32,070 identification of the amino acid 277 00:10:36,680 --> 00:10:34,290 inventory all the way from coming off of 278 00:10:38,960 --> 00:10:36,690 the citric acid cycle compounds to the 279 00:10:41,030 --> 00:10:38,970 first position on the codons and many 280 00:10:42,980 --> 00:10:41,040 other regularities through here was 281 00:10:44,690 --> 00:10:42,990 actually being done at the same time as 282 00:10:47,570 --> 00:10:44,700 at least the later stage of these 283 00:10:49,670 --> 00:10:47,580 assignments were being made so I want to 284 00:10:52,220 --> 00:10:49,680 introduce the concept of embodied 285 00:10:54,680 --> 00:10:52,230 information not merely combinatorial 286 00:10:56,680 --> 00:10:54,690 shuffling information but the idea that 287 00:10:59,360 --> 00:10:56,690 inherent in the chemistry and the 288 00:11:01,520 --> 00:10:59,370 limitations in chemical pathways to get 289 00:11:04,280 --> 00:11:01,530 somewhere is much of the information 290 00:11:07,460 --> 00:11:04,290 that we think of as essential to the 291 00:11:10,310 --> 00:11:07,470 nature of the only life we know 292 00:11:12,680 --> 00:11:10,320 and we can go beyond just the code we 293 00:11:14,060 --> 00:11:12,690 can think of RNA and DNA they are often 294 00:11:16,460 --> 00:11:14,070 thought of as the ultimate things 295 00:11:19,210 --> 00:11:16,470 selected to be carriers of any sequence 296 00:11:21,680 --> 00:11:19,220 but if you think about the biochemical 297 00:11:24,680 --> 00:11:21,690 synthetic networks of for instance 298 00:11:27,230 --> 00:11:24,690 purine RNA the embodied information in 299 00:11:30,020 --> 00:11:27,240 that is all information about crucial 300 00:11:32,150 --> 00:11:30,030 cofactors whether you consider histidine 301 00:11:34,130 --> 00:11:32,160 a cofactor or not we can talk about that 302 00:11:36,140 --> 00:11:34,140 but these things are essential in 303 00:11:37,970 --> 00:11:36,150 catalysis they aren't essential in one 304 00:11:39,800 --> 00:11:37,980 carbon transport and they're crucial 305 00:11:42,110 --> 00:11:39,810 cofactors in oxidation-reduction 306 00:11:44,630 --> 00:11:42,120 chemistry which are central to all of 307 00:11:47,870 --> 00:11:44,640 biochemistry and so I don't think you 308 00:11:49,900 --> 00:11:47,880 understand the biotic position and maybe 309 00:11:52,430 --> 00:11:49,910 not the abiotic position of RNA and DNA 310 00:11:55,130 --> 00:11:52,440 until you have understood the embodied 311 00:11:57,560 --> 00:11:55,140 information in this chemical Network 312 00:12:00,770 --> 00:11:57,570 that's preserved today in the cofactor 313 00:12:03,890 --> 00:12:00,780 world organism or eco system our third 314 00:12:05,120 --> 00:12:03,900 dichotomy Steve Gould in the structure 315 00:12:07,640 --> 00:12:05,130 of evolutionary theory makes the 316 00:12:10,250 --> 00:12:07,650 argument that Darwin was very focused on 317 00:12:12,530 --> 00:12:10,260 the organism as the unit of memory even 318 00:12:15,740 --> 00:12:12,540 though he was a consummate ecologist and 319 00:12:17,450 --> 00:12:15,750 from 1859 with the origin through the 320 00:12:19,160 --> 00:12:17,460 modern synthesis in the 30s with its 321 00:12:21,170 --> 00:12:19,170 emphasis on what we can say about the 322 00:12:23,330 --> 00:12:21,180 statistics of genomes to then the 323 00:12:25,310 --> 00:12:23,340 Williams Dawkins emphasis in the 60s on 324 00:12:29,030 --> 00:12:25,320 the gene is the building block of memory 325 00:12:31,670 --> 00:12:29,040 we have become progressively I would say 326 00:12:34,640 --> 00:12:31,680 narrower and harder in what we allow to 327 00:12:36,620 --> 00:12:34,650 be an evolutionary entity but I think 328 00:12:38,780 --> 00:12:36,630 this is an intellectual mistake because 329 00:12:42,080 --> 00:12:38,790 it increasingly takes the entities for 330 00:12:43,900 --> 00:12:42,090 granted and not explains why they exist 331 00:12:46,310 --> 00:12:43,910 and its ruling out the role of 332 00:12:48,530 --> 00:12:46,320 informational or relational variables as 333 00:12:50,330 --> 00:12:48,540 carriers of information now I won't talk 334 00:12:52,010 --> 00:12:50,340 about it today it's not like everyone 335 00:12:54,260 --> 00:12:52,020 has forgotten relations there is good 336 00:12:56,720 --> 00:12:54,270 pushback within science on what the 337 00:12:58,520 --> 00:12:56,730 relational variables carry but the 338 00:13:00,770 --> 00:12:58,530 important point is that in our formal 339 00:13:03,320 --> 00:13:00,780 theory of evolutionary memory population 340 00:13:06,050 --> 00:13:03,330 genetics the non entities become bean 341 00:13:10,910 --> 00:13:06,060 bags or communities the genome or the 342 00:13:12,620 --> 00:13:10,920 ecosystem and so they leave out the role 343 00:13:14,270 --> 00:13:12,630 of the relational variables what I want 344 00:13:16,520 --> 00:13:14,280 to show you in the next couple slides is 345 00:13:19,220 --> 00:13:16,530 that that narrow evolutionary view of 346 00:13:21,049 --> 00:13:19,230 entities does not actually say anything 347 00:13:23,059 --> 00:13:21,059 about the particularity of the bio 348 00:13:25,039 --> 00:13:23,069 chemistry I just showed you meaning that 349 00:13:26,629 --> 00:13:25,049 had the biochemistry been different we 350 00:13:29,029 --> 00:13:26,639 would tell exactly the same story about 351 00:13:31,309 --> 00:13:29,039 genes genomes and Darwinism which means 352 00:13:32,389 --> 00:13:31,319 that by being correct for everything 353 00:13:37,009 --> 00:13:32,399 they explained nothing 354 00:13:40,069 --> 00:13:37,019 so the embodied information I would say 355 00:13:42,919 --> 00:13:40,079 we have in these population level things 356 00:13:44,899 --> 00:13:42,929 takes the form of topologies how is it 357 00:13:47,989 --> 00:13:44,909 possible and how is it not possible to 358 00:13:50,719 --> 00:13:47,999 form a cell or an organism evolutionary 359 00:13:53,179 --> 00:13:50,729 change happens within the typology of 360 00:13:55,369 --> 00:13:53,189 the possible now for organisms the two 361 00:13:57,559 --> 00:13:55,379 most basic I would argue typological 362 00:13:59,899 --> 00:13:57,569 questions are is it autotrophic or 363 00:14:01,429 --> 00:13:59,909 heterotrophic so is it metabolically 364 00:14:03,619 --> 00:14:01,439 self-sufficient or can you not 365 00:14:05,359 --> 00:14:03,629 understand its metabolism except in the 366 00:14:08,239 --> 00:14:05,369 context of the ecosystem it depends on 367 00:14:10,609 --> 00:14:08,249 and is it an anaerobic or an aerobic 368 00:14:12,559 --> 00:14:10,619 metabolism fundamentally so are its 369 00:14:15,319 --> 00:14:12,569 energy sources more reduced or more 370 00:14:17,119 --> 00:14:15,329 oxidized than the net biological carbon 371 00:14:19,579 --> 00:14:17,129 now the interesting thing is that the 372 00:14:22,249 --> 00:14:19,589 anaerobic aerobic variable is also a 373 00:14:24,469 --> 00:14:22,259 type variable for ecosystems the auto 374 00:14:27,199 --> 00:14:24,479 hetero distinction requires the 375 00:14:29,749 --> 00:14:27,209 emergence of organisms to even become a 376 00:14:31,759 --> 00:14:29,759 meaningful thing to say whereas the 377 00:14:33,499 --> 00:14:31,769 arrow of anaerobe distinction does not 378 00:14:35,869 --> 00:14:33,509 and I'm going to argue that that's more 379 00:14:37,729 --> 00:14:35,879 fundamental and in particular that it is 380 00:14:39,619 --> 00:14:37,739 more closely connected to what I will 381 00:14:42,849 --> 00:14:39,629 say is the most universal feature in the 382 00:14:46,099 --> 00:14:42,859 biosphere and that's the following 383 00:14:48,019 --> 00:14:46,109 everything that you synthesize to make a 384 00:14:49,609 --> 00:14:48,029 living organism has its original 385 00:14:50,839 --> 00:14:49,619 starting point in one of four or five 386 00:14:52,269 --> 00:14:50,849 compounds that happen to be 387 00:14:54,409 --> 00:14:52,279 intermediates in the citric acid cycle 388 00:14:56,269 --> 00:14:54,419 there can be a lot of twists and turns 389 00:14:59,149 --> 00:14:56,279 building up and breaking down and 390 00:15:01,519 --> 00:14:59,159 shearing in ecosystems but this is true 391 00:15:03,709 --> 00:15:01,529 across everything that is preserved that 392 00:15:05,119 --> 00:15:03,719 we know of in the biosphere and as far 393 00:15:10,219 --> 00:15:05,129 as we know throughout the history of 394 00:15:13,249 --> 00:15:10,229 life now in order for that to be true 395 00:15:15,679 --> 00:15:13,259 that it's a biosynthetic Universal this 396 00:15:18,619 --> 00:15:15,689 is a picture of where it lies within a 397 00:15:20,689 --> 00:15:18,629 small network of 37 compounds which is 398 00:15:23,869 --> 00:15:20,699 the core of the core we can cut down the 399 00:15:26,479 --> 00:15:23,879 stree nevis on marwitz set of 125 small 400 00:15:29,479 --> 00:15:26,489 meta metabolites that are necessary and 401 00:15:32,179 --> 00:15:29,489 sufficient to this core which actually 402 00:15:34,070 --> 00:15:32,189 organizes them all in order for these to 403 00:15:36,470 --> 00:15:34,080 be the universal starting points in bio 404 00:15:38,270 --> 00:15:36,480 synthesis they must also have been the 405 00:15:40,940 --> 00:15:38,280 reference points for all subsequent 406 00:15:42,800 --> 00:15:40,950 evolutionary innovation so these are all 407 00:15:45,320 --> 00:15:42,810 of the other auto kettle auto catalytic 408 00:15:47,330 --> 00:15:45,330 loop feedback pathways drawn as a kind 409 00:15:49,130 --> 00:15:47,340 of a metro map with different pathways 410 00:15:50,930 --> 00:15:49,140 in different colors and the thing that 411 00:15:52,910 --> 00:15:50,940 you can see and it's a different talk to 412 00:15:55,820 --> 00:15:52,920 give you all the details on this is that 413 00:15:59,060 --> 00:15:55,830 they either reuse or re-enter or simply 414 00:16:01,430 --> 00:15:59,070 duplicate with some context change the 415 00:16:03,800 --> 00:16:01,440 arcs that are there in this core 416 00:16:06,620 --> 00:16:03,810 metabolism and all of this comes from 417 00:16:09,350 --> 00:16:06,630 the anaerobic world that is the core in 418 00:16:12,260 --> 00:16:09,360 both ecosystems or organisms so it's not 419 00:16:15,100 --> 00:16:12,270 a cellular property so the argument that 420 00:16:17,540 --> 00:16:15,110 I'll make is that the eco system is more 421 00:16:19,520 --> 00:16:17,550 fundamentally the explanatory unit for 422 00:16:22,700 --> 00:16:19,530 this Universal biochemistry than the 423 00:16:24,830 --> 00:16:22,710 organism is the reason being that the 424 00:16:26,990 --> 00:16:24,840 anchor status of the citric acid cycle 425 00:16:30,590 --> 00:16:27,000 or it's reductive version intermediate 426 00:16:32,300 --> 00:16:30,600 metabolites that can always be seen at 427 00:16:33,740 --> 00:16:32,310 the level of self-sufficient eco systems 428 00:16:35,060 --> 00:16:33,750 because they have to make everything we 429 00:16:37,100 --> 00:16:35,070 don't depend on carbon from space 430 00:16:39,950 --> 00:16:37,110 anymore if there was a time when we once 431 00:16:42,230 --> 00:16:39,960 did it happens that in the case for of 432 00:16:44,090 --> 00:16:42,240 autotrophic organisms you can see it at 433 00:16:45,710 --> 00:16:44,100 the level of the single organism but 434 00:16:48,260 --> 00:16:45,720 that's a question of how biochemistry 435 00:16:49,880 --> 00:16:48,270 comes under genomic control which is a 436 00:16:51,650 --> 00:16:49,890 higher-order organizational question 437 00:16:56,960 --> 00:16:51,660 it's not about the nature of what 438 00:16:59,180 --> 00:16:56,970 biochemistry must be so in evolutionary 439 00:17:01,160 --> 00:16:59,190 dynamics the embodied information about 440 00:17:04,130 --> 00:17:01,170 the precursors is carried not by 441 00:17:05,570 --> 00:17:04,140 individual descent lineages but by Co 442 00:17:08,030 --> 00:17:05,580 evolutionary dynamics where the 443 00:17:09,770 --> 00:17:08,040 ecosystem members affect each other 444 00:17:12,380 --> 00:17:09,780 now some of it can just reflect the 445 00:17:14,570 --> 00:17:12,390 environment passing through but the rest 446 00:17:16,640 --> 00:17:14,580 of it is frequency dependent fitness 447 00:17:18,110 --> 00:17:16,650 where completeness or compatibility is 448 00:17:20,420 --> 00:17:18,120 propagated through things like 449 00:17:21,980 --> 00:17:20,430 ecological stoichiometry to make sure 450 00:17:24,020 --> 00:17:21,990 that the members of the ecosystem do 451 00:17:26,180 --> 00:17:24,030 everything that needs to get done so 452 00:17:28,310 --> 00:17:26,190 coming back to Shostak subjection this 453 00:17:30,050 --> 00:17:28,320 looks very strong looking for life 454 00:17:31,520 --> 00:17:30,060 non-life categories in terms of these 455 00:17:35,690 --> 00:17:31,530 dichotomies doesn't seem to be working 456 00:17:37,880 --> 00:17:35,700 for us okay so why is that and what can 457 00:17:39,530 --> 00:17:37,890 we do is an alternative approach I would 458 00:17:42,020 --> 00:17:39,540 argue that the problem with this domain 459 00:17:43,670 --> 00:17:42,030 approach to starting is that every 460 00:17:45,680 --> 00:17:43,680 domain is carrying some features that 461 00:17:47,870 --> 00:17:45,690 are essential to life but for none of 462 00:17:51,020 --> 00:17:47,880 these do the features that that domain 463 00:17:52,880 --> 00:17:51,030 has seemed to pratima to account for all 464 00:17:56,150 --> 00:17:52,890 of the others that are also fundamental 465 00:17:58,790 --> 00:17:56,160 so instead of starting with domains can 466 00:18:01,310 --> 00:17:58,800 we make a kind of directed graph of the 467 00:18:04,010 --> 00:18:01,320 way information or constraint propagates 468 00:18:05,750 --> 00:18:04,020 from one domain to another and at the 469 00:18:08,510 --> 00:18:05,760 kind of beginning of that directed graph 470 00:18:10,130 --> 00:18:08,520 can we look for a starting point this is 471 00:18:12,230 --> 00:18:10,140 where the physicists have something to 472 00:18:13,460 --> 00:18:12,240 do that's not completely empty because 473 00:18:14,990 --> 00:18:13,470 this is a problem it's thoroughly 474 00:18:17,180 --> 00:18:15,000 understood for the hierarchy of matter 475 00:18:18,560 --> 00:18:17,190 this is the entire 20th century in 476 00:18:20,240 --> 00:18:18,570 physics and it's probably the best thing 477 00:18:23,060 --> 00:18:20,250 that's understood within the physical 478 00:18:24,860 --> 00:18:23,070 sciences it introduces a set of concepts 479 00:18:26,390 --> 00:18:24,870 that are readily applicable to life but 480 00:18:29,030 --> 00:18:26,400 that are not commonly used in biology 481 00:18:31,160 --> 00:18:29,040 and it's all about embodied information 482 00:18:32,930 --> 00:18:31,170 so let me give you some of this argument 483 00:18:38,600 --> 00:18:32,940 in a level of detail that I don't 484 00:18:40,670 --> 00:18:38,610 usually pursue in the simple physics of 485 00:18:43,160 --> 00:18:40,680 phase transitions the idea of embodiment 486 00:18:45,530 --> 00:18:43,170 means the structure of the state space 487 00:18:47,060 --> 00:18:45,540 this determines what information is 488 00:18:49,460 --> 00:18:47,070 available to be found when a phase 489 00:18:51,530 --> 00:18:49,470 transition happens Seth Lloyd in his 490 00:18:52,820 --> 00:18:51,540 book computing the universe likes to 491 00:18:55,160 --> 00:18:52,830 talk about hierarchies of phase 492 00:18:56,660 --> 00:18:55,170 transitions as creating information I'd 493 00:18:58,610 --> 00:18:56,670 rather say that the information is 494 00:19:00,560 --> 00:18:58,620 already there in the structure of the 495 00:19:03,080 --> 00:19:00,570 state space but when systems are 496 00:19:05,000 --> 00:19:03,090 amorphous they don't express it and when 497 00:19:08,030 --> 00:19:05,010 they freeze and become ordered that 498 00:19:09,650 --> 00:19:08,040 becomes expressed so the example is for 499 00:19:12,020 --> 00:19:09,660 instance a collection of spins that make 500 00:19:14,150 --> 00:19:12,030 up a magnet each of them might be up or 501 00:19:16,070 --> 00:19:14,160 down the state space is some hypercube 502 00:19:18,590 --> 00:19:16,080 whose dimension is how many spins there 503 00:19:20,030 --> 00:19:18,600 are there are lots of configurations 504 00:19:22,160 --> 00:19:20,040 where the number of up and down spins 505 00:19:24,470 --> 00:19:22,170 are about the same and if the magnet is 506 00:19:26,840 --> 00:19:24,480 hot you live in this domain of large 507 00:19:28,700 --> 00:19:26,850 numbers and you can't see that the up 508 00:19:30,920 --> 00:19:28,710 and the down are squeezed into little 509 00:19:34,250 --> 00:19:30,930 corners of the state space but as you 510 00:19:36,320 --> 00:19:34,260 freeze your actual system state gets 511 00:19:38,450 --> 00:19:36,330 stuck in one of these little corners and 512 00:19:39,860 --> 00:19:38,460 then the properties of the magnet start 513 00:19:41,780 --> 00:19:39,870 to display the properties of the 514 00:19:43,970 --> 00:19:41,790 squeezed corners of the state space and 515 00:19:46,280 --> 00:19:43,980 that formerly hidden information becomes 516 00:19:47,840 --> 00:19:46,290 available so I'm going to add a couple 517 00:19:50,020 --> 00:19:47,850 of other concepts to this and then argue 518 00:19:52,130 --> 00:19:50,030 that we can do this for life as well 519 00:19:54,470 --> 00:19:52,140 second concept that's brought into 520 00:19:55,970 --> 00:19:54,480 existence by phase transitions is what 521 00:19:57,080 --> 00:19:55,980 we'll call long-range order and this is 522 00:20:00,260 --> 00:19:57,090 where we're going to get directionality 523 00:20:01,560 --> 00:20:00,270 from the idea is the following when 524 00:20:03,510 --> 00:20:01,570 something freezes you 525 00:20:05,930 --> 00:20:03,520 a bunch of local degrees of freedom or 526 00:20:08,880 --> 00:20:05,940 building blocks that might have some 527 00:20:10,500 --> 00:20:08,890 group of configurations they can occupy 528 00:20:11,910 --> 00:20:10,510 and when they're melted the groups are 529 00:20:14,430 --> 00:20:11,920 all independent so we write it as a 530 00:20:16,500 --> 00:20:14,440 product but any product could also be 531 00:20:18,750 --> 00:20:16,510 written as a collective effect where 532 00:20:21,660 --> 00:20:18,760 they all do the same thing which is then 533 00:20:23,460 --> 00:20:21,670 this h1 and then the first difference 534 00:20:25,590 --> 00:20:23,470 where they deviate from doing the same 535 00:20:27,360 --> 00:20:25,600 thing that's h2 and we can go and we can 536 00:20:29,970 --> 00:20:27,370 fill out the same state space the same 537 00:20:31,830 --> 00:20:29,980 way when something freezes one of these 538 00:20:33,540 --> 00:20:31,840 collective things gets frozen and they 539 00:20:35,490 --> 00:20:33,550 get stuck in a corner of the state space 540 00:20:37,380 --> 00:20:35,500 and they can't sample everything anymore 541 00:20:40,200 --> 00:20:37,390 and it's only the remaining degrees of 542 00:20:42,780 --> 00:20:40,210 freedom that wind up free to vary this 543 00:20:44,880 --> 00:20:42,790 story of phase transitions turns out to 544 00:20:46,830 --> 00:20:44,890 be the entire modern theory of the 545 00:20:48,750 --> 00:20:46,840 hierarchy of matter and if you look at 546 00:20:51,030 --> 00:20:48,760 these iconic graphs going from the Big 547 00:20:53,250 --> 00:20:51,040 Bang to the modern world every one of 548 00:20:55,590 --> 00:20:53,260 these transitions is one of these 549 00:20:57,750 --> 00:20:55,600 freezing's the interesting reason 550 00:20:59,430 --> 00:20:57,760 there's directionality in this is that 551 00:21:02,190 --> 00:20:59,440 the more local the degrees of freedom 552 00:21:04,980 --> 00:21:02,200 are the ones that are easier to find the 553 00:21:07,290 --> 00:21:04,990 order in they make smaller building 554 00:21:09,090 --> 00:21:07,300 blocks and they're more rigid those 555 00:21:11,430 --> 00:21:09,100 rigid building blocks that assemble 556 00:21:14,700 --> 00:21:11,440 first act as constraints on what can be 557 00:21:16,950 --> 00:21:14,710 assembled later and because a constraint 558 00:21:19,290 --> 00:21:16,960 is a restriction on the available state 559 00:21:21,420 --> 00:21:19,300 space that propagates upward in the 560 00:21:23,250 --> 00:21:21,430 hierarchy of form as a kind of 561 00:21:26,970 --> 00:21:23,260 information and this is where I'm gonna 562 00:21:28,800 --> 00:21:26,980 argue embodied information comes from so 563 00:21:30,540 --> 00:21:28,810 here's an example where that argument 564 00:21:31,110 --> 00:21:30,550 was has been invoked explicitly in 565 00:21:33,840 --> 00:21:31,120 biology 566 00:21:35,880 --> 00:21:33,850 remember the genetic code what kind of 567 00:21:38,280 --> 00:21:35,890 information could be selected for in the 568 00:21:40,710 --> 00:21:38,290 genetic code you would think the genetic 569 00:21:42,510 --> 00:21:40,720 code could should be a firewall because 570 00:21:44,490 --> 00:21:42,520 there's all this inescapable structure 571 00:21:46,110 --> 00:21:44,500 and metabolism and you don't want that 572 00:21:48,060 --> 00:21:46,120 propagating through to your sequence 573 00:21:49,500 --> 00:21:48,070 world you want any sequence to be 574 00:21:51,600 --> 00:21:49,510 available so that proteins can be 575 00:21:54,150 --> 00:21:51,610 selected based on the phenotype the 576 00:21:56,790 --> 00:21:54,160 reason you can't that code should not be 577 00:21:59,160 --> 00:21:56,800 completely agnostic about structure is 578 00:22:00,690 --> 00:21:59,170 that translation doesn't always work 579 00:22:03,780 --> 00:22:00,700 perfectly and some of this structure 580 00:22:05,400 --> 00:22:03,790 leaks through so if the codons are 581 00:22:07,950 --> 00:22:05,410 arranged in such a way that they can 582 00:22:10,620 --> 00:22:07,960 mask the errors as much as possible you 583 00:22:12,300 --> 00:22:10,630 can get a flatter state space here than 584 00:22:13,760 --> 00:22:12,310 the structured state space of the 585 00:22:16,970 --> 00:22:13,770 chemistry that's leaking through 586 00:22:18,680 --> 00:22:16,980 in selecting what your molecules are so 587 00:22:20,930 --> 00:22:18,690 nitrile golden Feld and Colleen vets 588 00:22:22,910 --> 00:22:20,940 Egon and Carl was following up on some 589 00:22:26,540 --> 00:22:22,920 of Carl's ideas about the Darwinian 590 00:22:28,330 --> 00:22:26,550 threshold a few years ago asked is it 591 00:22:30,919 --> 00:22:28,340 realistic to think that codon 592 00:22:33,230 --> 00:22:30,929 rearrangements can actually get a 593 00:22:35,390 --> 00:22:33,240 genetic code that is as good at 594 00:22:38,360 --> 00:22:35,400 buffering as the code we actually see 595 00:22:40,460 --> 00:22:38,370 and their argument was after the 596 00:22:42,169 --> 00:22:40,470 Darwinian threshold when organisms have 597 00:22:44,330 --> 00:22:42,179 barriers against horizontal gene 598 00:22:46,760 --> 00:22:44,340 transfer and the components of the 599 00:22:49,790 --> 00:22:46,770 ribosome in different organisms are not 600 00:22:51,860 --> 00:22:49,800 permitted to be exchanged because that's 601 00:22:54,260 --> 00:22:51,870 too damaging to the fidelity of 602 00:22:56,919 --> 00:22:54,270 translation in such a world there is 603 00:23:00,290 --> 00:22:56,929 long-range order and you can't actually 604 00:23:02,600 --> 00:23:00,300 rearrange the codons well enough to get 605 00:23:04,790 --> 00:23:02,610 the degree of buffering we see it is 606 00:23:07,130 --> 00:23:04,800 only in a world of extensive horizontal 607 00:23:09,560 --> 00:23:07,140 gene transfer where you make the fitness 608 00:23:12,049 --> 00:23:09,570 of a gene local you evaluate it in the 609 00:23:14,600 --> 00:23:12,059 context of all other genes where it 610 00:23:17,180 --> 00:23:14,610 could occupy an organism and then you 611 00:23:19,250 --> 00:23:17,190 make your your proteins statistical so 612 00:23:21,650 --> 00:23:19,260 that they are robust against all the 613 00:23:23,900 --> 00:23:21,660 errors in that ugly world and therefore 614 00:23:26,419 --> 00:23:23,910 they're tolerant of exchange of coding 615 00:23:29,060 --> 00:23:26,429 positions only in that kind of a world 616 00:23:30,860 --> 00:23:29,070 can you actually optimize to the point 617 00:23:33,049 --> 00:23:30,870 where you get a code that is as good as 618 00:23:35,510 --> 00:23:33,059 the code we see so the mess the 619 00:23:38,299 --> 00:23:35,520 substance of their message is that this 620 00:23:40,250 --> 00:23:38,309 thermalization which then locks in the 621 00:23:42,620 --> 00:23:40,260 optimal genetic code when the ribosome 622 00:23:45,830 --> 00:23:42,630 becomes accurate and the Darwinian world 623 00:23:47,419 --> 00:23:45,840 of persistent lineages emerges only that 624 00:23:49,549 --> 00:23:47,429 thermalization was a kind of Vic in 625 00:23:51,860 --> 00:23:49,559 Stein's letter on which the biosphere 626 00:23:55,970 --> 00:23:51,870 could have climbed up with a solution 627 00:23:57,260 --> 00:23:55,980 that it currently has so the reason we 628 00:23:59,720 --> 00:23:57,270 can make use of some of this 629 00:24:02,000 --> 00:23:59,730 quantitatively is that the story I just 630 00:24:04,760 --> 00:24:02,010 told you has mathematical structure the 631 00:24:06,919 --> 00:24:04,770 important way to understand the origin 632 00:24:10,010 --> 00:24:06,929 of directionality is to recognize that 633 00:24:13,190 --> 00:24:10,020 robustness in phase transitions comes in 634 00:24:14,930 --> 00:24:13,200 classes the master formula for 635 00:24:16,460 --> 00:24:14,940 everything in fact I don't know if you 636 00:24:18,530 --> 00:24:16,470 realize there was a master formula for 637 00:24:20,660 --> 00:24:18,540 everything this is called the formula 638 00:24:23,659 --> 00:24:20,670 for large deviations scaling and it is 639 00:24:25,310 --> 00:24:23,669 the reason a macro world exists it says 640 00:24:27,200 --> 00:24:25,320 that when you have probability 641 00:24:27,980 --> 00:24:27,210 distributions for systems with a lot of 642 00:24:30,620 --> 00:24:27,990 component 643 00:24:33,289 --> 00:24:30,630 the only times you get a macro world is 644 00:24:36,769 --> 00:24:33,299 when the probability turns out to split 645 00:24:38,480 --> 00:24:36,779 into a term where the scale can vary in 646 00:24:40,960 --> 00:24:38,490 a way that doesn't have to be precise 647 00:24:44,029 --> 00:24:40,970 but the structure of the macro world 648 00:24:46,370 --> 00:24:44,039 remains well-defined across a whole 649 00:24:48,230 --> 00:24:46,380 variety of scales this is what you don't 650 00:24:50,299 --> 00:24:48,240 have in the micro world where it matters 651 00:24:52,460 --> 00:24:50,309 whether you have one two or three 652 00:24:54,440 --> 00:24:52,470 molecules but you do have in the world 653 00:24:57,380 --> 00:24:54,450 of a cat where it doesn't matter whether 654 00:25:00,529 --> 00:24:57,390 the cat has inhaled or exhaled more or 655 00:25:02,450 --> 00:25:00,539 fewer molecules of o2 or co2 and the 656 00:25:04,820 --> 00:25:02,460 place where phase transitions occur is 657 00:25:07,370 --> 00:25:04,830 when these structure factors factors 658 00:25:09,740 --> 00:25:07,380 change between one major domain and 659 00:25:11,659 --> 00:25:09,750 another the interesting thing is that 660 00:25:13,610 --> 00:25:11,669 the characteristics of structure are 661 00:25:16,340 --> 00:25:13,620 different in different classes of phase 662 00:25:18,889 --> 00:25:16,350 transitions so there are some for which 663 00:25:21,169 --> 00:25:18,899 there's only solution only one solution 664 00:25:23,269 --> 00:25:21,179 like an ideal gas this vial of chlorine 665 00:25:25,340 --> 00:25:23,279 you will always go to the same state 666 00:25:26,810 --> 00:25:25,350 there are others like the simple 667 00:25:30,409 --> 00:25:26,820 second-order phase transitions like 668 00:25:32,180 --> 00:25:30,419 Frost where the crystal magnitude will 669 00:25:34,580 --> 00:25:32,190 look the same but the direction is 670 00:25:36,649 --> 00:25:34,590 uncertain and these guys can drift over 671 00:25:38,149 --> 00:25:36,659 time but it's a closed-ended drift and I 672 00:25:39,980 --> 00:25:38,159 mean this in the sense of closed-ended 673 00:25:42,409 --> 00:25:39,990 evolution and then the furthest we've 674 00:25:44,419 --> 00:25:42,419 gotten in physics is to look at glasses 675 00:25:47,240 --> 00:25:44,429 where you now have a set of possible 676 00:25:49,279 --> 00:25:47,250 solutions that are indefinitely large as 677 00:25:51,950 --> 00:25:49,289 the system becomes big and they can 678 00:25:55,549 --> 00:25:51,960 drift in an open-ended way in finite 679 00:25:57,799 --> 00:25:55,559 systems so does the biosphere have such 680 00:26:00,320 --> 00:25:57,809 closed and open-ended I would argue yes 681 00:26:01,940 --> 00:26:00,330 the biosphere contains chance and 682 00:26:04,279 --> 00:26:01,950 necessity and they are all equally 683 00:26:06,590 --> 00:26:04,289 fundamental aspects of life the small 684 00:26:08,750 --> 00:26:06,600 molecule world looks more like the 685 00:26:10,370 --> 00:26:08,760 necessary geochemical world than it 686 00:26:12,289 --> 00:26:10,380 looks like the world of the accidents of 687 00:26:14,330 --> 00:26:12,299 species and then many aspects of 688 00:26:18,139 --> 00:26:14,340 cellular architecture live somewhere 689 00:26:19,399 --> 00:26:18,149 along the spectrum between I'm very 690 00:26:20,419 --> 00:26:19,409 nearly out of time their stuff it won't 691 00:26:22,909 --> 00:26:20,429 be able to show you but I'll show you a 692 00:26:25,820 --> 00:26:22,919 couple more things the fascinating thing 693 00:26:27,919 --> 00:26:25,830 is that in the biosphere there is an 694 00:26:29,659 --> 00:26:27,929 inverse hierarchy you know they say 695 00:26:31,370 --> 00:26:29,669 diamonds are forever diamonds are not 696 00:26:33,139 --> 00:26:31,380 forever on the surface of the earth but 697 00:26:35,600 --> 00:26:33,149 they will last longer than the person 698 00:26:39,049 --> 00:26:35,610 you give them to and that's enough but 699 00:26:41,660 --> 00:26:39,059 in the world in the world of equilibrium 700 00:26:43,610 --> 00:26:41,670 physics the unit cell of the diamond is 701 00:26:45,980 --> 00:26:43,620 persistent because the diamond is hard 702 00:26:48,350 --> 00:26:45,990 and durable in the biosphere it's 703 00:26:50,720 --> 00:26:48,360 exactly the opposite the most durable 704 00:26:52,640 --> 00:26:50,730 patterns the the metabolic chart that I 705 00:26:54,740 --> 00:26:52,650 showed you are carried by the small 706 00:26:56,360 --> 00:26:54,750 metabolites that turn over on time 707 00:26:59,750 --> 00:26:56,370 scales from milliseconds to tens of 708 00:27:02,480 --> 00:26:59,760 seconds individual organisms last longer 709 00:27:05,660 --> 00:27:02,490 they can be twenty minutes to perhaps a 710 00:27:07,460 --> 00:27:05,670 hundred years species may have a tenure 711 00:27:09,070 --> 00:27:07,470 going up to a million years as a 712 00:27:11,660 --> 00:27:09,080 characteristic figure of Merit 713 00:27:13,790 --> 00:27:11,670 ecosystems can switch on a time scale 714 00:27:16,220 --> 00:27:13,800 from a month to the durations of 715 00:27:19,070 --> 00:27:16,230 keystone species in them the interesting 716 00:27:20,630 --> 00:27:19,080 thing is that the more durable the 717 00:27:22,820 --> 00:27:20,640 pattern we're talking about were the 718 00:27:25,250 --> 00:27:22,830 entities of that pattern the more 719 00:27:27,800 --> 00:27:25,260 arbitrary and the less stable in 720 00:27:29,540 --> 00:27:27,810 geological time that pattern is so I 721 00:27:31,640 --> 00:27:29,550 want to argue in the previous story 722 00:27:34,070 --> 00:27:31,650 about local things being robust things 723 00:27:37,460 --> 00:27:34,080 that it is precisely this smallness in 724 00:27:39,440 --> 00:27:37,470 space and short turnover in time that 725 00:27:43,520 --> 00:27:39,450 identifies the starting point for cause 726 00:27:46,280 --> 00:27:43,530 in the biosphere now the reason this 727 00:27:48,800 --> 00:27:46,290 subject has teeth is that everything we 728 00:27:51,500 --> 00:27:48,810 can do in equilibrium phase transitions 729 00:27:53,180 --> 00:27:51,510 can be mapped to dynamics and the 730 00:27:55,280 --> 00:27:53,190 fascinating thing is that when you do 731 00:27:58,040 --> 00:27:55,290 map it to dynamics you are in the world 732 00:28:00,140 --> 00:27:58,050 of dynamical error correction so this is 733 00:28:02,000 --> 00:28:00,150 the mapping we can come back and I can 734 00:28:04,010 --> 00:28:02,010 talk offline about all these particular 735 00:28:05,210 --> 00:28:04,020 things they're laid out here but the 736 00:28:07,700 --> 00:28:05,220 important point is there are new 737 00:28:10,280 --> 00:28:07,710 concepts that are introduced in optimal 738 00:28:12,590 --> 00:28:10,290 error correction that enable us I think 739 00:28:17,030 --> 00:28:12,600 to get better clarity on what we see in 740 00:28:20,660 --> 00:28:17,040 the biological world around us I can't 741 00:28:22,070 --> 00:28:20,670 do this so I'm gonna skip to something 742 00:28:25,400 --> 00:28:22,080 because this is a point that can be made 743 00:28:26,780 --> 00:28:25,410 simply in any error correcting system 744 00:28:29,480 --> 00:28:26,790 where you have only finitely many 745 00:28:31,880 --> 00:28:29,490 degrees of freedom that are used to look 746 00:28:35,690 --> 00:28:31,890 for errors through redundancy and to 747 00:28:38,990 --> 00:28:35,700 correct them anything finite will always 748 00:28:41,780 --> 00:28:39,000 with certainty eventually decode to the 749 00:28:43,970 --> 00:28:41,790 wrong answer the only thing that never 750 00:28:45,860 --> 00:28:43,980 decodes to the wrong answer is something 751 00:28:48,100 --> 00:28:45,870 like the ideal-gas that only has one 752 00:28:51,200 --> 00:28:48,110 answer so the code is not doing anything 753 00:28:53,180 --> 00:28:51,210 in the biological world the only thing 754 00:28:54,669 --> 00:28:53,190 that there's exactly one of is the 755 00:28:57,009 --> 00:28:54,679 universal format at 756 00:28:58,629 --> 00:28:57,019 all the rest of these guys are error 757 00:29:01,779 --> 00:28:58,639 messages that are carried with finite 758 00:29:06,370 --> 00:29:01,789 probability of error so I will stop in 759 00:29:08,139 --> 00:29:06,380 honor of time do you have another minute 760 00:29:09,460 --> 00:29:08,149 to wrap up and leave you with the 761 00:29:13,149 --> 00:29:09,470 summary comments there's other stuff 762 00:29:15,129 --> 00:29:13,159 that I'm happy to cover the main things 763 00:29:18,159 --> 00:29:15,139 that I want to take I want to give you 764 00:29:20,499 --> 00:29:18,169 to take from this are that when we take 765 00:29:22,149 --> 00:29:20,509 the mathematically founded concepts of 766 00:29:24,129 --> 00:29:22,159 phases that are understood well in 767 00:29:26,110 --> 00:29:24,139 equilibrium into the dynamical world 768 00:29:27,999 --> 00:29:26,120 that we need to understand biology they 769 00:29:30,549 --> 00:29:28,009 do not look like the physics of 770 00:29:32,649 --> 00:29:30,559 equilibrium except mathematically they 771 00:29:35,080 --> 00:29:32,659 become the theory of optimal error 772 00:29:37,529 --> 00:29:35,090 correction about which we have our own 773 00:29:39,909 --> 00:29:37,539 base of knowledge important thing 774 00:29:42,100 --> 00:29:39,919 comprehensive asymptotically reliable 775 00:29:44,560 --> 00:29:42,110 error correction meaning the biosphere 776 00:29:46,570 --> 00:29:44,570 has been with a planet the entire time 777 00:29:48,700 --> 00:29:46,580 even though all of its subunits of 778 00:29:50,110 --> 00:29:48,710 organization turnover that's the 779 00:29:52,269 --> 00:29:50,120 elephant in the room not only of all 780 00:29:54,100 --> 00:29:52,279 biology but of all reductionist science 781 00:29:57,220 --> 00:29:54,110 we don't have a theory of where that 782 00:29:58,869 --> 00:29:57,230 comes from the fact that it has a sub 783 00:30:00,700 --> 00:29:58,879 structure allows us to interpret 784 00:30:03,100 --> 00:30:00,710 biological phenomena in terms of 785 00:30:06,100 --> 00:30:03,110 directionality an important three-way 786 00:30:09,190 --> 00:30:06,110 trade off between redundancy complexity 787 00:30:11,350 --> 00:30:09,200 and reliability is what gives us the 788 00:30:13,180 --> 00:30:11,360 hierarchy where local things are rigid 789 00:30:16,629 --> 00:30:13,190 and the prior sources of constraint and 790 00:30:19,269 --> 00:30:16,639 the asymptotic unreliability of anything 791 00:30:21,669 --> 00:30:19,279 finite if it has any nonzero complexity 792 00:30:24,610 --> 00:30:21,679 is what gives us the need for unn codes 793 00:30:26,560 --> 00:30:24,620 that are the reference for everything 794 00:30:28,269 --> 00:30:26,570 else to come back to and I want to argue 795 00:30:30,610 --> 00:30:28,279 that universal core metabolism is the 796 00:30:32,769 --> 00:30:30,620 unco dand it's the classical state 797 00:30:35,710 --> 00:30:32,779 variable for the biosphere that defines 798 00:30:37,299 --> 00:30:35,720 the nature of life so all of the rest of 799 00:30:39,100 --> 00:30:37,309 the complexity is still there and it's 800 00:30:40,299 --> 00:30:39,110 as hard as it ever was this is only 801 00:30:41,649 --> 00:30:40,309 meant to be a way to try to 802 00:30:43,940 --> 00:30:41,659 systematically look at how we choose 803 00:30:49,640 --> 00:30:43,950 projects in it thank you Thanks 804 00:30:52,440 --> 00:30:49,650 [Applause] 805 00:30:58,470 --> 00:30:52,450 so now we have time for questions 806 00:31:05,400 --> 00:30:58,480 I saw marks hand go up first we have so 807 00:31:08,820 --> 00:31:05,410 you have some marked right here it's a 808 00:31:09,960 --> 00:31:08,830 one question about the directionality do 809 00:31:12,990 --> 00:31:09,970 you think that the direct channel is 810 00:31:13,320 --> 00:31:13,000 affected by hysteresis and it's in any 811 00:31:16,020 --> 00:31:13,330 way 812 00:31:18,750 --> 00:31:16,030 so is there memory of how life you is 813 00:31:20,690 --> 00:31:18,760 the process of going from one phase 814 00:31:23,760 --> 00:31:20,700 transition to the next if you will 815 00:31:25,470 --> 00:31:23,770 affecting the evolution so if you change 816 00:31:31,050 --> 00:31:25,480 is somehow is there a memory of that 817 00:31:33,660 --> 00:31:31,060 changing for some things almost surely 818 00:31:36,480 --> 00:31:33,670 for other things I think it's less 819 00:31:39,120 --> 00:31:36,490 likely so Kurt Vonnegut wrote a book 820 00:31:40,980 --> 00:31:39,130 called cat's cradle about somebody who 821 00:31:42,330 --> 00:31:40,990 discovers a new form of ice that in all 822 00:31:44,100 --> 00:31:42,340 the oceans and all the history of the 823 00:31:45,990 --> 00:31:44,110 world was never discovered even though 824 00:31:47,550 --> 00:31:46,000 it happens at room temperature and it 825 00:31:49,980 --> 00:31:47,560 brings an end to the world because it 826 00:31:51,870 --> 00:31:49,990 propagates and freezes everything that 827 00:31:54,210 --> 00:31:51,880 kind of thing I think we can say never 828 00:31:56,700 --> 00:31:54,220 happens because the problem of finding 829 00:31:58,320 --> 00:31:56,710 an orientation of ice requires only 830 00:32:00,690 --> 00:31:58,330 getting a couple molecules into the 831 00:32:03,000 --> 00:32:00,700 right orientation so nothing like that 832 00:32:04,890 --> 00:32:03,010 has an opportunity for hysteresis those 833 00:32:07,230 --> 00:32:04,900 are the sorts of things where unique 834 00:32:10,290 --> 00:32:07,240 solutions get found incredibly robustly 835 00:32:12,270 --> 00:32:10,300 and usually very fast it is not clear 836 00:32:14,430 --> 00:32:12,280 yet whether core metabolism has that 837 00:32:15,900 --> 00:32:14,440 status and on a slide I didn't show you 838 00:32:17,700 --> 00:32:15,910 about where the forefront of current 839 00:32:18,750 --> 00:32:17,710 work is the reason it's not clear is 840 00:32:20,100 --> 00:32:18,760 that we don't know enough about the 841 00:32:22,290 --> 00:32:20,110 chemical state space in the chemical 842 00:32:23,970 --> 00:32:22,300 process space that question is 843 00:32:26,070 --> 00:32:23,980 answerable with work within the 844 00:32:28,410 --> 00:32:26,080 reasonable time frame of decades if we 845 00:32:30,930 --> 00:32:28,420 can just get organized and do it if you 846 00:32:32,820 --> 00:32:30,940 look at other things as far out as the 847 00:32:35,310 --> 00:32:32,830 distinction between simple amino acids 848 00:32:36,990 --> 00:32:35,320 and more complex amino acids or some of 849 00:32:39,300 --> 00:32:37,000 the later stages and biosynthesis of the 850 00:32:42,270 --> 00:32:39,310 cofactors I think there you may have a 851 00:32:44,280 --> 00:32:42,280 strong argument that ex-post selection 852 00:32:46,320 --> 00:32:44,290 can lock in features that are partly 853 00:32:48,750 --> 00:32:46,330 arbitrary and that have very long 854 00:32:50,910 --> 00:32:48,760 downstream consequences so for instance 855 00:32:53,820 --> 00:32:50,920 look at arginine as an amino acid has a 856 00:32:55,620 --> 00:32:53,830 very very specific role as positively 857 00:32:57,810 --> 00:32:55,630 charged coordination groups in all 858 00:32:59,610 --> 00:32:57,820 protein structure but the biosynthesis 859 00:33:00,270 --> 00:32:59,620 of that does not look like something 860 00:33:01,890 --> 00:33:00,280 that's 861 00:33:03,780 --> 00:33:01,900 absolutely inevitable given core 862 00:33:05,400 --> 00:33:03,790 metabolism looks like a sort of thing 863 00:33:08,490 --> 00:33:05,410 that can be locked in at a later stage 864 00:33:10,980 --> 00:33:08,500 so I think we see a progression from 865 00:33:12,810 --> 00:33:10,990 less to more hysteresis and to quantify 866 00:33:17,760 --> 00:33:12,820 that is one of the important areas of 867 00:33:19,140 --> 00:33:17,770 work yes sir um 868 00:33:20,640 --> 00:33:19,150 you use the word Universal core 869 00:33:23,190 --> 00:33:20,650 metabolism and I and I assume you mean 870 00:33:24,390 --> 00:33:23,200 global core metabolism or do you really 871 00:33:26,340 --> 00:33:24,400 mean universal in the sense that we 872 00:33:28,290 --> 00:33:26,350 should look for it on Mars and other 873 00:33:30,000 --> 00:33:28,300 earth-like planets elsewhere in the 874 00:33:31,920 --> 00:33:30,010 universe but the question then becomes 875 00:33:33,980 --> 00:33:31,930 if we're gonna look for this core 876 00:33:37,020 --> 00:33:33,990 metabolism what is the biggest 877 00:33:39,030 --> 00:33:37,030 observational signature of it that we 878 00:33:41,160 --> 00:33:39,040 would look for on a place like Mars or 879 00:33:43,470 --> 00:33:41,170 eventually other planets the atmospheres 880 00:33:45,300 --> 00:33:43,480 of chemical disequilibrium and other 881 00:33:47,580 --> 00:33:45,310 planets yeah great 882 00:33:49,470 --> 00:33:47,590 when I say Universal I mean empirically 883 00:33:52,440 --> 00:33:49,480 Universal with respect to the way all 884 00:33:54,570 --> 00:33:52,450 the life forms we know use it I do I 885 00:33:56,490 --> 00:33:54,580 cannot yet make the claim that it is 886 00:33:58,680 --> 00:33:56,500 predicted from first principles of 887 00:34:00,600 --> 00:33:58,690 physics and a knowledge of the planetary 888 00:34:01,800 --> 00:34:00,610 boundary conditions for exactly the 889 00:34:03,030 --> 00:34:01,810 point we just discussed we don't know 890 00:34:05,400 --> 00:34:03,040 enough about the state space the 891 00:34:08,070 --> 00:34:05,410 question about how you map that into 892 00:34:10,980 --> 00:34:08,080 exoplanet signatures is actually really 893 00:34:13,350 --> 00:34:10,990 hard because the difference between a 894 00:34:17,250 --> 00:34:13,360 nonliving earth and alert and earth with 895 00:34:20,130 --> 00:34:17,260 only anaerobic life unless rosing and 896 00:34:22,950 --> 00:34:20,140 sleep and Alberta Day are right and this 897 00:34:24,990 --> 00:34:22,960 has an effect on continent formation 898 00:34:26,940 --> 00:34:25,000 that you can separate from a null model 899 00:34:28,770 --> 00:34:26,950 that you can control I don't even know 900 00:34:31,560 --> 00:34:28,780 what you look for in planetary surface 901 00:34:32,730 --> 00:34:31,570 conditions the sledgehammer on earth was 902 00:34:34,649 --> 00:34:32,740 the emergence of oxygen 'ok 903 00:34:37,320 --> 00:34:34,659 photosynthesis and the burial of the 904 00:34:39,690 --> 00:34:37,330 resulting organic carbon and even that 905 00:34:40,919 --> 00:34:39,700 the exoplanet people are still willing 906 00:34:43,440 --> 00:34:40,929 to argue about whether they could 907 00:34:45,720 --> 00:34:43,450 reliably distinguish and that's between 908 00:34:46,950 --> 00:34:45,730 you know the Archaean and the 909 00:34:49,409 --> 00:34:46,960 Proterozoic that's not part of the 910 00:34:50,970 --> 00:34:49,419 universal core but how that I don't 911 00:34:55,010 --> 00:34:50,980 think we can argue as part of the 912 00:35:03,120 --> 00:34:55,020 universal core from the things I can see 913 00:35:08,999 --> 00:35:05,809 I was going to ask a similar question 914 00:35:10,620 --> 00:35:09,009 basically the universal core would be 915 00:35:13,829 --> 00:35:10,630 the equivalent of a thermodynamic 916 00:35:15,089 --> 00:35:13,839 minimum is that correct exactly it would 917 00:35:17,069 --> 00:35:15,099 be a state variable that there's only 918 00:35:19,829 --> 00:35:17,079 one solution right so is there any way 919 00:35:21,599 --> 00:35:19,839 to actually do a delta on that and test 920 00:35:26,460 --> 00:35:21,609 to see whether or not it falls back into 921 00:35:28,950 --> 00:35:26,470 that minimum I don't know how you do 922 00:35:31,440 --> 00:35:28,960 that experimentally on the time scales 923 00:35:34,920 --> 00:35:31,450 we have but I do think that you can use 924 00:35:37,950 --> 00:35:34,930 comparative evolutionary analysis to 925 00:35:41,279 --> 00:35:37,960 make arguments that are not completely 926 00:35:44,700 --> 00:35:41,289 empty so evolution is full of dogs that 927 00:35:46,740 --> 00:35:44,710 didn't bark in the sense that once you 928 00:35:48,359 --> 00:35:46,750 have the sophistication of genomes and 929 00:35:51,319 --> 00:35:48,369 proteins you would think you could 930 00:35:53,700 --> 00:35:51,329 innovate an awful lot of stuff and yet 931 00:35:55,680 --> 00:35:53,710 innovation in things like carbon 932 00:35:57,839 --> 00:35:55,690 fixation pathways has been extremely 933 00:36:01,039 --> 00:35:57,849 limited and it has apparently existed 934 00:36:03,839 --> 00:36:01,049 within a restricted frame in time so of 935 00:36:05,789 --> 00:36:03,849 course the things that are not strong 936 00:36:08,099 --> 00:36:05,799 enough to be constraints in the sense 937 00:36:09,990 --> 00:36:08,109 that there's no possible variation can 938 00:36:12,329 --> 00:36:10,000 still show up as strong forces to 939 00:36:14,220 --> 00:36:12,339 evolutionary convergence or the 940 00:36:19,680 --> 00:36:14,230 inability for things to gain a fitness 941 00:36:22,109 --> 00:36:19,690 advantage from by deviating from so it's 942 00:36:25,079 --> 00:36:22,119 not as good as a controlled experiment 943 00:36:26,519 --> 00:36:25,089 but we can try to argue that the absence 944 00:36:28,980 --> 00:36:26,529 of innovations where you would think 945 00:36:31,349 --> 00:36:28,990 genomically we had the technology to do 946 00:36:33,870 --> 00:36:31,359 it points to paths of least resistance 947 00:36:37,099 --> 00:36:33,880 in the small molecule chemistry that 948 00:36:46,609 --> 00:36:37,109 there was no advantage to departing from 949 00:36:52,740 --> 00:36:49,560 so the universal core is a product of an 950 00:36:55,260 --> 00:36:52,750 information processing as well it has 951 00:36:57,090 --> 00:36:55,270 enzymes and and it was our product of 952 00:37:00,480 --> 00:36:57,100 the information so where would that 953 00:37:03,570 --> 00:37:00,490 leave them the universal core core being 954 00:37:05,430 --> 00:37:03,580 on a product of encode yeah uncoated 955 00:37:07,650 --> 00:37:05,440 I don't think I would say it's a product 956 00:37:09,750 --> 00:37:07,660 of them I would say that the only place 957 00:37:12,720 --> 00:37:09,760 we see it today is where it's supported 958 00:37:15,570 --> 00:37:12,730 by them it may be because it's a product 959 00:37:17,130 --> 00:37:15,580 of them but it could be that we have a 960 00:37:20,400 --> 00:37:17,140 new thing in science that we have to 961 00:37:22,560 --> 00:37:20,410 understand which is how can there be 962 00:37:24,690 --> 00:37:22,570 only one solution to something but the 963 00:37:26,940 --> 00:37:24,700 only context in which we see that one 964 00:37:28,620 --> 00:37:26,950 solution is when it's supported by 965 00:37:44,030 --> 00:37:28,630 feedback from things that have many 966 00:37:44,040 --> 00:37:51,300 Charlie that's one 967 00:37:54,750 --> 00:37:53,520 erican the beginning of you talk you you 968 00:37:56,400 --> 00:37:54,760 mentioned you had a nice diagram where 969 00:37:58,530 --> 00:37:56,410 you've talked about otto and hetero and 970 00:38:01,050 --> 00:37:58,540 then you've compared that to anaerobe 971 00:38:03,150 --> 00:38:01,060 purses arrow and you said that one of 972 00:38:04,770 --> 00:38:03,160 those dichotomies was more fundamental 973 00:38:06,690 --> 00:38:04,780 than the other one yeah for an argument 974 00:38:08,580 --> 00:38:06,700 I did I couldn't follow that could you 975 00:38:10,110 --> 00:38:08,590 okay clean a little bit sure in order 976 00:38:12,420 --> 00:38:10,120 for something to be an autotroph or a 977 00:38:14,010 --> 00:38:12,430 heterotroph it has to actually exist as 978 00:38:15,930 --> 00:38:14,020 an organism that's distinct from the 979 00:38:18,660 --> 00:38:15,940 ecosystem that it inhabits or that is 980 00:38:20,160 --> 00:38:18,670 coextensive with the ecosystem right so 981 00:38:22,230 --> 00:38:20,170 an autotroph is biochemically 982 00:38:24,030 --> 00:38:22,240 self-sufficient which means that you can 983 00:38:26,220 --> 00:38:24,040 put it in a mineral medium and it will 984 00:38:28,170 --> 00:38:26,230 survive a heterotroph is not 985 00:38:30,090 --> 00:38:28,180 biochemically self-sufficient which 986 00:38:32,460 --> 00:38:30,100 means without the detailed dependence on 987 00:38:33,720 --> 00:38:32,470 its ecosystem it doesn't persist but 988 00:38:36,090 --> 00:38:33,730 that's actually a question of the 989 00:38:38,570 --> 00:38:36,100 relation between biochemistry and the 990 00:38:43,110 --> 00:38:38,580 way genome control is partitioned among 991 00:38:45,030 --> 00:38:43,120 autonomous units and that's distinct 992 00:38:46,620 --> 00:38:45,040 from the question of whether or not your 993 00:38:48,090 --> 00:38:46,630 electron flow is downhill in the 994 00:38:51,540 --> 00:38:48,100 reducing direction or downhill in the 995 00:38:54,270 --> 00:38:51,550 oxidizing direction yes but you said one 996 00:38:56,910 --> 00:38:54,280 of those dichotomies was more Universal 997 00:38:58,920 --> 00:38:56,920 I can't I can't express Auto hetero 998 00:39:00,900 --> 00:38:58,930 dichotomy for an ecosystem because all 999 00:39:04,530 --> 00:39:00,910 ecosystems are self-sufficient there is 1000 00:39:07,320 --> 00:39:04,540 no distinction available so anaerobe and 1001 00:39:10,890 --> 00:39:07,330 air robe is the more fundamental thing 1002 00:39:12,600 --> 00:39:10,900 that came first and then came the yeah 1003 00:39:14,430 --> 00:39:12,610 it's more than I gave you reason to 1004 00:39:16,500 --> 00:39:14,440 believe in this talk but I would argue 1005 00:39:19,490 --> 00:39:16,510 that that is a prior constraint at the 1006 00:39:22,590 --> 00:39:19,500 ecosystem level and that then organism 1007 00:39:24,930 --> 00:39:22,600 organization distills out of that once 1008 00:39:26,760 --> 00:39:24,940 you solve a lot of other problems of how 1009 00:39:30,180 --> 00:39:26,770 you want to partition the control of 1010 00:39:33,030 --> 00:39:30,190 that biochemistry under the mechanism of 1011 00:39:33,930 --> 00:39:33,040 Darwinian selection acting on genomes so 1012 00:39:38,910 --> 00:39:33,940 another way to say that is that 1013 00:39:40,410 --> 00:39:38,920 ecosystems are Auto know that that's a 1014 00:39:42,330 --> 00:39:40,420 very popular way to say it but I think 1015 00:39:44,220 --> 00:39:42,340 that is one of these popular things in 1016 00:39:46,830 --> 00:39:44,230 science that makes it harder to think 1017 00:39:49,560 --> 00:39:46,840 clearly Auto trophy and hetero trophy 1018 00:39:52,230 --> 00:39:49,570 are ecological concepts and so to talk 1019 00:39:54,600 --> 00:39:52,240 about an ecosystem as being autotrophic 1020 00:39:56,400 --> 00:39:54,610 is to take the term out of the place 1021 00:39:57,960 --> 00:39:56,410 where it makes a helpful distinction and 1022 00:40:03,549 --> 00:39:57,970 put it into a place where it makes it 1023 00:40:11,870 --> 00:40:05,809 just to continue on this question how do 1024 00:40:13,819 --> 00:40:11,880 you define an ecosystem them an eco said 1025 00:40:18,229 --> 00:40:13,829 okay good there are two ways you can 1026 00:40:20,479 --> 00:40:18,239 look at it the way that is less than 1027 00:40:22,699 --> 00:40:20,489 complete is to define an ecosystem as an 1028 00:40:24,680 --> 00:40:22,709 assembled community of member species 1029 00:40:26,959 --> 00:40:24,690 that have some necessary relations to 1030 00:40:28,819 --> 00:40:26,969 each other biochemical or behavioral or 1031 00:40:31,130 --> 00:40:28,829 niche constructing or whatever 1032 00:40:33,650 --> 00:40:31,140 I think that's inadequate because it 1033 00:40:35,719 --> 00:40:33,660 denies the ecosystem the status of being 1034 00:40:37,699 --> 00:40:35,729 an elementary entity in its own right 1035 00:40:39,410 --> 00:40:37,709 and I think that's what gave us the 1036 00:40:41,779 --> 00:40:39,420 unfortunate departure into the Gaia 1037 00:40:43,999 --> 00:40:41,789 hypothesis because they were left with 1038 00:40:46,249 --> 00:40:44,009 no way to refer to the ecosystem as an 1039 00:40:48,529 --> 00:40:46,259 elementary entity they had to try to 1040 00:40:50,420 --> 00:40:48,539 call it a super organism but it's not 1041 00:40:53,509 --> 00:40:50,430 organized and it doesn't change the way 1042 00:40:55,999 --> 00:40:53,519 an organism does ecosystems may be more 1043 00:40:58,039 --> 00:40:56,009 or less self-sufficient so to do this 1044 00:41:00,349 --> 00:40:58,049 carefully what you want to say is with 1045 00:41:09,999 --> 00:41:00,359 respect to a certain criterion of 1046 00:41:14,989 --> 00:41:13,489 or coral reef is for other purposes a 1047 00:41:16,309 --> 00:41:14,999 lake or a coral reef are not 1048 00:41:24,549 --> 00:41:16,319 self-sufficient enough and you have to 1049 00:41:24,559 --> 00:41:32,060 okay so thank you Eric