1
00:00:14,629 --> 00:00:11,830
cool well thank you all for coming

2
00:00:17,109 --> 00:00:14,639
what i want to talk about is the section

3
00:00:19,269 --> 00:00:17,119
uh of our brainstorming around

4
00:00:21,429 --> 00:00:19,279
what are the common attributes of

5
00:00:23,830 --> 00:00:21,439
excellent living systems

6
00:00:25,509 --> 00:00:23,840
and what can they tell us about all

7
00:00:30,710 --> 00:00:25,519
living systems

8
00:00:33,990 --> 00:00:31,910
there we go

9
00:00:35,990 --> 00:00:34,000
our explanation

10
00:00:38,150 --> 00:00:36,000
living systems from cells and

11
00:00:39,910 --> 00:00:38,160
populations of cells to higher order

12
00:00:42,069 --> 00:00:39,920
structures including multicellular

13
00:00:44,150 --> 00:00:42,079
organisms share a set of common

14
00:00:46,069 --> 00:00:44,160
attributes that distinguish them from

15
00:00:48,150 --> 00:00:46,079
non-living systems

16
00:00:49,990 --> 00:00:48,160
an important goal of astrobiology should

17
00:00:52,389 --> 00:00:50,000
be to identify the attributes or

18
00:00:54,389 --> 00:00:52,399
principles of system composition that

19
00:00:56,869 --> 00:00:54,399
collectively would enable us after

20
00:00:58,869 --> 00:00:56,879
taking correct account of the chemistry

21
00:01:00,869 --> 00:00:58,879
upon which a living system might be

22
00:01:03,430 --> 00:01:00,879
based to recognize systems of being

23
00:01:05,189 --> 00:01:03,440
alive a consensus as to the nature of

24
00:01:07,270 --> 00:01:05,199
these attributes and an understanding of

25
00:01:09,190 --> 00:01:07,280
the roles that chance contingency and

26
00:01:11,190 --> 00:01:09,200
necessity play in their origin and

27
00:01:14,149 --> 00:01:11,200
elaboration are essential to being able

28
00:01:17,030 --> 00:01:14,159
to recognize and describe life on other

29
00:01:32,630 --> 00:01:19,190
so

30
00:01:35,830 --> 00:01:34,149
uh yes

31
00:01:37,830 --> 00:01:35,840
interesting question by bob i think

32
00:01:40,550 --> 00:01:37,840
we'll come back to that in the comments

33
00:01:42,950 --> 00:01:40,560
i wanted to say a word about probability

34
00:01:44,789 --> 00:01:42,960
chance and necessity this is not in the

35
00:01:46,710 --> 00:01:44,799
paper itself but

36
00:01:48,550 --> 00:01:46,720
just for some context

37
00:01:51,429 --> 00:01:48,560
chance we're looking at questions of

38
00:01:53,270 --> 00:01:51,439
properties of earth life which

39
00:01:55,350 --> 00:01:53,280
we will which we suspect will have

40
00:01:57,590 --> 00:01:55,360
arisen due to stochastic events in

41
00:01:59,429 --> 00:01:57,600
earth's history for example right-handed

42
00:02:01,429 --> 00:01:59,439
sugars may have been more common in the

43
00:02:03,109 --> 00:02:01,439
original environment so when we're

44
00:02:05,190 --> 00:02:03,119
talking about chants we're talking about

45
00:02:07,510 --> 00:02:05,200
these kinds of things that might have

46
00:02:08,949 --> 00:02:07,520
arisen not because they had to but just

47
00:02:12,390 --> 00:02:08,959
because they happen to in the

48
00:02:14,070 --> 00:02:12,400
environment life found itself

49
00:02:16,550 --> 00:02:14,080
second we have this category of

50
00:02:18,390 --> 00:02:16,560
contingency some properties of earth

51
00:02:20,470 --> 00:02:18,400
life we suspect will have arisen due to

52
00:02:22,869 --> 00:02:20,480
contingent events in earth's history for

53
00:02:25,030 --> 00:02:22,879
example the chick shalom impact which

54
00:02:28,470 --> 00:02:25,040
eliminated larger animals and made way

55
00:02:30,869 --> 00:02:28,480
for the rise of large mammals now both

56
00:02:32,550 --> 00:02:30,879
of these hypotheses have certain aspects

57
00:02:34,150 --> 00:02:32,560
to them which you may or may not agree

58
00:02:35,910 --> 00:02:34,160
with that's not really important here

59
00:02:38,470 --> 00:02:35,920
the question is the types of

60
00:02:42,150 --> 00:02:38,480
explanations we want to invoke and what

61
00:02:45,270 --> 00:02:42,160
they say about our understanding of life

62
00:02:47,190 --> 00:02:45,280
third we have a category of necessity

63
00:02:48,869 --> 00:02:47,200
some properties of earth life we suspect

64
00:02:50,550 --> 00:02:48,879
will have arisen due to necessary

65
00:02:52,790 --> 00:02:50,560
features of the earth necessary

66
00:02:54,710 --> 00:02:52,800
responses to features of the earth's

67
00:02:56,869 --> 00:02:54,720
environment for example terrestrial

68
00:02:58,470 --> 00:02:56,879
organisms need protection terrestrial

69
00:03:00,869 --> 00:02:58,480
that is living on

70
00:03:02,830 --> 00:03:00,879
land organisms need protection from

71
00:03:05,910 --> 00:03:02,840
oxidation and uv

72
00:03:09,750 --> 00:03:05,920
radiation so those are our categories of

73
00:03:11,990 --> 00:03:09,760
chance contingency and necessity

74
00:03:14,710 --> 00:03:12,000
coming back to the language of the white

75
00:03:16,470 --> 00:03:14,720
paper living systems here on earth share

76
00:03:19,750 --> 00:03:16,480
common features that broadly fall into

77
00:03:22,869 --> 00:03:19,760
categories related to their energetics

78
00:03:24,869 --> 00:03:22,879
composition structure function

79
00:03:27,350 --> 00:03:24,879
information in terms of content

80
00:03:28,869 --> 00:03:27,360
retrieval and transmission

81
00:03:31,509 --> 00:03:28,879
living systems self-organize

82
00:03:34,550 --> 00:03:31,519
self-perpetuate and adapt as individuals

83
00:03:36,309 --> 00:03:34,560
but also as populations to spatial and

84
00:03:37,750 --> 00:03:36,319
temporal variability in resource

85
00:03:41,430 --> 00:03:37,760
availability

86
00:03:43,509 --> 00:03:41,440
and physical conditions

87
00:03:45,589 --> 00:03:43,519
adaptations can result from events that

88
00:03:47,589 --> 00:03:45,599
may or may not be repeated if repeated

89
00:03:49,830 --> 00:03:47,599
they will produce

90
00:03:52,470 --> 00:03:49,840
we wonder if repeated will they always

91
00:03:54,390 --> 00:03:52,480
produce the same evolutionary result

92
00:03:56,390 --> 00:03:54,400
examples of this include ubiquitous

93
00:03:57,910 --> 00:03:56,400
traits that arise relatively easily in

94
00:03:59,670 --> 00:03:57,920
independent lineages and then are

95
00:04:02,550 --> 00:03:59,680
conserved as in the case of

96
00:04:04,630 --> 00:04:02,560
multicellularity

97
00:04:06,949 --> 00:04:04,640
also traits that are ubiquitous among

98
00:04:08,949 --> 00:04:06,959
unrelated taxa because they solve common

99
00:04:09,910 --> 00:04:08,959
problems in a similar

100
00:04:11,750 --> 00:04:09,920
way

101
00:04:13,589 --> 00:04:11,760
so here we have

102
00:04:15,030 --> 00:04:13,599
another digression

103
00:04:18,229 --> 00:04:15,040
i'm just going to make distinguish

104
00:04:20,469 --> 00:04:18,239
between shared ancestral traits you can

105
00:04:23,749 --> 00:04:20,479
see on the chart here we have this green

106
00:04:25,270 --> 00:04:23,759
region which is the pisces or fish

107
00:04:27,510 --> 00:04:25,280
and they all

108
00:04:29,270 --> 00:04:27,520
have certain features because the first

109
00:04:31,510 --> 00:04:29,280
organism in the group had certain

110
00:04:33,909 --> 00:04:31,520
features that other groups have emerged

111
00:04:36,950 --> 00:04:33,919
from within our group of fish and you

112
00:04:42,150 --> 00:04:36,960
see here the rise of

113
00:04:46,950 --> 00:04:44,629
likewise we have shared derived traits

114
00:04:49,670 --> 00:04:46,960
synapomorphies um there isn't a

115
00:04:51,270 --> 00:04:49,680
synapomorphy marked on this chart but uh

116
00:04:53,590 --> 00:04:51,280
you can see the little node here that i

117
00:04:56,390 --> 00:04:53,600
have marked in red everything from then

118
00:04:58,629 --> 00:04:56,400
on out has a spine so that's the

119
00:05:01,990 --> 00:04:58,639
vertebral group all members of the group

120
00:05:06,310 --> 00:05:04,150
that is a shared derived trait and

121
00:05:09,029 --> 00:05:06,320
finally we have

122
00:05:10,790 --> 00:05:09,039
convergence

123
00:05:13,189 --> 00:05:10,800
you can look at two traits like the

124
00:05:14,150 --> 00:05:13,199
mammals and the birds both of them

125
00:05:15,909 --> 00:05:14,160
have

126
00:05:17,749 --> 00:05:15,919
um

127
00:05:19,510 --> 00:05:17,759
heat regulation

128
00:05:21,510 --> 00:05:19,520
so they're capable of maintaining their

129
00:05:24,150 --> 00:05:21,520
internal temperature separate from the

130
00:05:27,029 --> 00:05:24,160
external temperature but those we

131
00:05:29,029 --> 00:05:27,039
believe arose independently but we also

132
00:05:31,430 --> 00:05:29,039
think they arose as a response to the

133
00:05:33,110 --> 00:05:31,440
same problem so when we're looking at

134
00:05:35,749 --> 00:05:33,120
adaptations we want to know what kind of

135
00:05:37,670 --> 00:05:35,759
problem they're responding to and in

136
00:05:39,830 --> 00:05:37,680
another origin of life would they be

137
00:05:41,590 --> 00:05:39,840
responding to the same problems

138
00:05:44,070 --> 00:05:41,600
so coming back to the original language

139
00:05:46,230 --> 00:05:44,080
again adaptations likely to be repeated

140
00:05:48,469 --> 00:05:46,240
for these reasons are predictable given

141
00:05:49,749 --> 00:05:48,479
a defined set of conditions we would

142
00:05:57,350 --> 00:05:49,759
expect these attributes to be

143
00:06:01,029 --> 00:05:58,870
so once again we've got these shared

144
00:06:03,909 --> 00:06:01,039
ancestral traits we want to know whether

145
00:06:06,150 --> 00:06:03,919
they are adaptations that are necessary

146
00:06:10,230 --> 00:06:06,160
to life necessary to a particular early

147
00:06:12,309 --> 00:06:10,240
environment on earth or just contingent

148
00:06:14,550 --> 00:06:12,319
responses or responses to contingent

149
00:06:16,230 --> 00:06:14,560
events in the external environment like

150
00:06:18,230 --> 00:06:16,240
the chick-fil-a impact

151
00:06:21,029 --> 00:06:18,240
we also have these shared derived and

152
00:06:23,270 --> 00:06:21,039
convergent traits and we want to know to

153
00:06:25,270 --> 00:06:23,280
what they're adapting and is it likely

154
00:06:26,790 --> 00:06:25,280
that extraterrestrial life would also

155
00:06:27,749 --> 00:06:26,800
have to adapt to

156
00:06:31,189 --> 00:06:27,759
such

157
00:06:35,590 --> 00:06:33,270
justification a better understanding of

158
00:06:37,110 --> 00:06:35,600
the common attributes of living systems

159
00:06:39,029 --> 00:06:37,120
and the degree to which they were formed

160
00:06:40,550 --> 00:06:39,039
during contingent or inevitable events

161
00:06:42,629 --> 00:06:40,560
will help us predict the attributes of

162
00:06:44,390 --> 00:06:42,639
life on other planets knowledge of

163
00:06:48,950 --> 00:06:44,400
present consistency can help us

164
00:06:50,950 --> 00:06:48,960
reconstruct historical dates

165
00:06:53,110 --> 00:06:50,960
that brings us to our sub questions the

166
00:06:54,390 --> 00:06:53,120
ones that we have identified are certain

167
00:06:55,270 --> 00:06:54,400
there are more

168
00:06:57,510 --> 00:06:55,280
are

169
00:06:59,510 --> 00:06:57,520
one what would be recognizable on other

170
00:07:01,430 --> 00:06:59,520
worlds in the context of the chemistry

171
00:07:03,830 --> 00:07:01,440
of those worlds that would enable us to

172
00:07:06,550 --> 00:07:03,840
infer the presence of life's attributes

173
00:07:09,749 --> 00:07:06,560
so what are those necessary

174
00:07:11,909 --> 00:07:09,759
adaptations we believe for all life on

175
00:07:13,189 --> 00:07:11,919
any given environment

176
00:07:15,270 --> 00:07:13,199
are there features of life that are

177
00:07:17,189 --> 00:07:15,280
universal and if so how might these be

178
00:07:21,029 --> 00:07:17,199
detected that is are there things that

179
00:07:23,909 --> 00:07:21,039
life necessarily must do wherever it is

180
00:07:26,230 --> 00:07:23,919
this connects with the question of bio

181
00:07:28,070 --> 00:07:26,240
signatures

182
00:07:29,909 --> 00:07:28,080
sub question two

183
00:07:32,230 --> 00:07:29,919
why is the emergence of individuality

184
00:07:33,909 --> 00:07:32,240
such a large factor in driven

185
00:07:35,430 --> 00:07:33,919
non-equilibrium

186
00:07:37,510 --> 00:07:35,440
processes

187
00:07:39,589 --> 00:07:37,520
so again and again in our discussions we

188
00:07:42,469 --> 00:07:39,599
came back to this idea of

189
00:07:47,029 --> 00:07:42,479
uh hierarchical levels of organization

190
00:07:48,870 --> 00:07:47,039
and how they reflect adaptations to the

191
00:07:51,029 --> 00:07:48,880
environment to what extent is

192
00:07:53,350 --> 00:07:51,039
organization into individual units of

193
00:07:55,990 --> 00:07:53,360
ontogeny and selection inevitable in or

194
00:07:58,230 --> 00:07:56,000
entailed by the emergence of persistent

195
00:08:00,950 --> 00:07:58,240
order in driven systems where it often

196
00:08:02,790 --> 00:08:00,960
is not in equilibrium ordered systems

197
00:08:05,110 --> 00:08:02,800
what kinds of major organizational

198
00:08:06,550 --> 00:08:05,120
transitions bring individuality into

199
00:08:09,270 --> 00:08:06,560
existence or change the levels of

200
00:08:11,510 --> 00:08:09,280
hierarchical organization and nesting of

201
00:08:13,189 --> 00:08:11,520
individual forms

202
00:08:17,189 --> 00:08:13,199
you can see there's a little bit of a

203
00:08:18,869 --> 00:08:17,199
definition of life creeping in here

204
00:08:21,350 --> 00:08:18,879
i don't think that's necessary to

205
00:08:24,790 --> 00:08:21,360
subscribe to to understand the general

206
00:08:26,550 --> 00:08:24,800
idea of necessity and contingency in the

207
00:08:28,070 --> 00:08:26,560
history of life

208
00:08:30,070 --> 00:08:28,080
but it shows you somewhat what we were

209
00:08:31,270 --> 00:08:30,080
thinking when we were talking about the

210
00:08:36,149 --> 00:08:31,280
question

211
00:08:39,990 --> 00:08:36,159
and contingency play in the origin and

212
00:08:40,790 --> 00:08:40,000
elaboration of cellular nano machines

213
00:08:42,630 --> 00:08:40,800
um

214
00:08:44,630 --> 00:08:42,640
what is the limited set of modular nano

215
00:08:46,630 --> 00:08:44,640
machines absolutely required to explain

216
00:08:48,470 --> 00:08:46,640
the common attributes of all life but

217
00:08:50,070 --> 00:08:48,480
larger set of nano machines explains the

218
00:08:52,150 --> 00:08:50,080
distinctive attributes of all forms of

219
00:08:53,990 --> 00:08:52,160
life on earth

220
00:08:56,070 --> 00:08:54,000
such machines are recognized more by

221
00:08:57,990 --> 00:08:56,080
their function than by their structure

222
00:08:59,590 --> 00:08:58,000
for example while energy harvesting may

223
00:09:01,190 --> 00:08:59,600
be a characteristic attribute of all

224
00:09:02,870 --> 00:09:01,200
life forms diverse structures realize

225
00:09:04,550 --> 00:09:02,880
this attribute contingent on a

226
00:09:06,550 --> 00:09:04,560
particular lineage's evolutionary

227
00:09:09,030 --> 00:09:06,560
history in the context of environmental

228
00:09:10,710 --> 00:09:09,040
redox and available minerals

229
00:09:13,030 --> 00:09:10,720
there's an interesting use of the word

230
00:09:16,310 --> 00:09:13,040
nano machines that i had not encountered

231
00:09:18,389 --> 00:09:16,320
prior to the meeting

232
00:09:20,550 --> 00:09:18,399
but basically i think here we're trying

233
00:09:23,509 --> 00:09:20,560
to capture the idea that there are

234
00:09:25,509 --> 00:09:23,519
processes running within the cell and we

235
00:09:28,310 --> 00:09:25,519
are looking at how those processes

236
00:09:31,269 --> 00:09:28,320
evolved uh what they're adapting to what

237
00:09:33,269 --> 00:09:31,279
purposes they're serving

238
00:09:35,190 --> 00:09:33,279
question four what roles did chance and

239
00:09:37,509 --> 00:09:35,200
contingency play in determining major

240
00:09:39,990 --> 00:09:37,519
evolutionary transitions in history of

241
00:09:41,430 --> 00:09:40,000
life on earth

242
00:09:42,949 --> 00:09:41,440
a suite of major evolutionary

243
00:09:44,630 --> 00:09:42,959
transitions have been identified

244
00:09:46,550 --> 00:09:44,640
beginning with the origin of life and

245
00:09:48,230 --> 00:09:46,560
metabolism and extending through the

246
00:09:49,829 --> 00:09:48,240
origin of multicellularity to the

247
00:09:52,710 --> 00:09:49,839
evolution of social organisms and

248
00:09:55,509 --> 00:09:52,720
language this approach to mets focuses

249
00:09:57,750 --> 00:09:55,519
on changes in packaging information but

250
00:09:59,350 --> 00:09:57,760
there are alternative approaches to mets

251
00:10:01,190 --> 00:09:59,360
identifying environmental and

252
00:10:03,350 --> 00:10:01,200
developmental factors

253
00:10:04,710 --> 00:10:03,360
there is a great need for identifying

254
00:10:06,470 --> 00:10:04,720
excuse me there's a great need for

255
00:10:07,990 --> 00:10:06,480
connecting these different approaches

256
00:10:10,710 --> 00:10:08,000
and understanding the environmental

257
00:10:12,630 --> 00:10:10,720
context for meps the relative importance

258
00:10:14,389 --> 00:10:12,640
of contingency chance and necessity in

259
00:10:17,269 --> 00:10:14,399
the major mets of interest through

260
00:10:19,350 --> 00:10:17,279
astrobiology remains unresolved progress

261
00:10:21,030 --> 00:10:19,360
has been made in some areas such as

262
00:10:23,509 --> 00:10:21,040
whether the genetic code is a frozen

263
00:10:26,230 --> 00:10:23,519
accident or suggested by crick

264
00:10:27,670 --> 00:10:26,240
or as suggested

265
00:10:29,190 --> 00:10:27,680
excuse me

266
00:10:31,110 --> 00:10:29,200
weather genetic code is a frozen

267
00:10:33,190 --> 00:10:31,120
accident as suggested by crick and in

268
00:10:34,949 --> 00:10:33,200
aspects of cellularity

269
00:10:37,030 --> 00:10:34,959
yet the issue has hardly been addressed

270
00:10:38,630 --> 00:10:37,040
for other nats resolving this issue is

271
00:10:40,870 --> 00:10:38,640
critical for understanding the extent to

272
00:10:42,790 --> 00:10:40,880
which we can generalize from mets on

273
00:10:47,030 --> 00:10:42,800
earth to complex life

274
00:10:50,069 --> 00:10:48,710
uh similar to what i was talking about

275
00:10:52,630 --> 00:10:50,079
for the nano machines but here we're

276
00:10:55,350 --> 00:10:52,640
asking questions of how necessary is it

277
00:10:58,230 --> 00:10:55,360
to make transitions perhaps to higher

278
00:11:01,910 --> 00:10:58,240
levels of organization or

279
00:11:06,389 --> 00:11:03,990
five what is the correct understanding

280
00:11:07,509 --> 00:11:06,399
of earth life in context that would lead

281
00:11:09,829 --> 00:11:07,519
us to look for the correct

282
00:11:12,389 --> 00:11:09,839
characteristics of life in non-earth

283
00:11:14,949 --> 00:11:12,399
context so this is trying to separate

284
00:11:17,269 --> 00:11:14,959
out the differential differences between

285
00:11:20,870 --> 00:11:17,279
contingent life properties on earth and

286
00:11:21,750 --> 00:11:20,880
necessary life properties everywhere

287
00:11:23,910 --> 00:11:21,760
six

288
00:11:25,990 --> 00:11:23,920
if earth organisms exist that represent

289
00:11:28,550 --> 00:11:26,000
a second origin of life how would we

290
00:11:30,550 --> 00:11:28,560
recognize and differentiate them

291
00:11:32,470 --> 00:11:30,560
certainly this question of shadow life

292
00:11:35,750 --> 00:11:32,480
on earth begs the question

293
00:11:37,269 --> 00:11:35,760
of is there in fact some other

294
00:11:39,590 --> 00:11:37,279
type of earth

295
00:11:43,110 --> 00:11:39,600
some other type of life on earth other

296
00:11:44,870 --> 00:11:43,120
than the type we see in humans and c

297
00:11:47,350 --> 00:11:44,880
elegans and all the other things we

298
00:11:49,350 --> 00:11:47,360
normally associate with the tree of life

299
00:11:54,230 --> 00:11:49,360
if there is a type of life other than

300
00:11:58,310 --> 00:11:56,470
seven are there regimes or eras of

301
00:12:00,150 --> 00:11:58,320
evolutionary history that were

302
00:12:02,310 --> 00:12:00,160
constrained by different evolutionary

303
00:12:03,990 --> 00:12:02,320
rules or environmental processes

304
00:12:05,910 --> 00:12:04,000
for example following catastrophic

305
00:12:08,389 --> 00:12:05,920
extinctions were certain ecological

306
00:12:10,790 --> 00:12:08,399
rules suspended or altered are they

307
00:12:13,030 --> 00:12:10,800
capitulated at are they recapitulated at

308
00:12:14,550 --> 00:12:13,040
smaller spatial scales

309
00:12:16,310 --> 00:12:14,560
so here we're looking at this question

310
00:12:17,509 --> 00:12:16,320
of whether

311
00:12:19,430 --> 00:12:17,519
really we're looking at the question of

312
00:12:22,829 --> 00:12:19,440
how we want to characterize

313
00:12:25,350 --> 00:12:22,839
periods of time on earth when the

314
00:12:27,829 --> 00:12:25,360
adaptive constraints were

315
00:12:29,590 --> 00:12:27,839
different perhaps than they are now

316
00:12:32,069 --> 00:12:29,600
certainly the

317
00:12:33,509 --> 00:12:32,079
reducing atmosphere of early earth and

318
00:12:35,030 --> 00:12:33,519
the oxygenetic

319
00:12:37,430 --> 00:12:35,040
arm

320
00:12:40,150 --> 00:12:37,440
and the oxygenized atmosphere we

321
00:12:42,150 --> 00:12:40,160
currently have represent two different

322
00:12:44,389 --> 00:12:42,160
regimes so we're interested in the

323
00:12:46,389 --> 00:12:44,399
question of whether adaptations will be

324
00:12:48,870 --> 00:12:46,399
different at different times and whether

325
00:12:50,790 --> 00:12:48,880
we can expect similar adaptations for

326
00:12:52,710 --> 00:12:50,800
other planets one of the things that

327
00:12:55,350 --> 00:12:52,720
we're particularly looking at is this

328
00:12:56,470 --> 00:12:55,360
question of

329
00:12:58,629 --> 00:12:56,480
oxygen

330
00:13:03,670 --> 00:12:58,639
on other planets we usually consider an

331
00:13:05,430 --> 00:13:03,680
oxygen signature to be a good way of

332
00:13:07,750 --> 00:13:05,440
convincing ourselves that there might be

333
00:13:09,590 --> 00:13:07,760
life on another planet if that's the

334
00:13:11,110 --> 00:13:09,600
case then we can say an oxygenated

335
00:13:13,590 --> 00:13:11,120
atmosphere might be one of the

336
00:13:17,430 --> 00:13:13,600
conditions that life we're looking for

337
00:13:19,509 --> 00:13:17,440
elsewhere would have to adapt to

338
00:13:21,590 --> 00:13:19,519
eight what are the specific attributes

339
00:13:22,949 --> 00:13:21,600
of life at the base of the evolutionary

340
00:13:25,430 --> 00:13:22,959
tree so

341
00:13:26,550 --> 00:13:25,440
we're thinking if we can reconstruct the

342
00:13:28,710 --> 00:13:26,560
traits at the beginning of the

343
00:13:31,509 --> 00:13:28,720
evolutionary tree we can

344
00:13:33,670 --> 00:13:31,519
compare that to the environment on early

345
00:13:36,230 --> 00:13:33,680
earth when we expect the

346
00:13:39,430 --> 00:13:36,240
earliest organisms to have existed and

347
00:13:41,110 --> 00:13:39,440
use those to constrain the necessary and

348
00:13:43,590 --> 00:13:41,120
contingent

349
00:13:49,829 --> 00:13:47,829
and adaptations at that period of time

350
00:13:51,910 --> 00:13:49,839
what attributes of organisms species

351
00:13:53,910 --> 00:13:51,920
ecosystems etc have repeatedly

352
00:13:55,829 --> 00:13:53,920
originated by convergent evolution and

353
00:13:58,790 --> 00:13:55,839
under what circumstances would they be

354
00:14:01,990 --> 00:13:58,800
likely to appear or not on other planets

355
00:14:06,150 --> 00:14:04,470
been proposed for example that once you

356
00:14:07,269 --> 00:14:06,160
have a lot of life you will expect to

357
00:14:10,069 --> 00:14:07,279
find life

358
00:14:12,069 --> 00:14:10,079
somewhere in the atmosphere uh above the

359
00:14:14,790 --> 00:14:12,079
surface does that

360
00:14:17,269 --> 00:14:14,800
because there is space there does that

361
00:14:18,389 --> 00:14:17,279
mean that there is necessarily

362
00:14:19,829 --> 00:14:18,399
uh

363
00:14:21,910 --> 00:14:19,839
going to be some organism that has

364
00:14:23,829 --> 00:14:21,920
adapted to fill that space are there

365
00:14:26,069 --> 00:14:23,839
niches that we would expect to appear on

366
00:14:28,150 --> 00:14:26,079
any um

367
00:14:33,110 --> 00:14:28,160
on any planet uh that we expect

368
00:14:36,710 --> 00:14:34,710
10 is it inevitable that units of

369
00:14:40,310 --> 00:14:36,720
selection cluster into forms that act as

370
00:14:44,550 --> 00:14:40,320
higher level units of selection

371
00:14:46,470 --> 00:14:44,560
we can ask questions of whether the

372
00:14:48,069 --> 00:14:46,480
structure of cells

373
00:14:51,430 --> 00:14:48,079
is something that we think would be

374
00:14:52,870 --> 00:14:51,440
repeated whether the

375
00:14:58,710 --> 00:14:52,880
symbioses

376
00:15:01,990 --> 00:14:58,720
mitochondria and chloroplast

377
00:15:03,590 --> 00:15:02,000
might be such an advantageous adaptation

378
00:15:05,590 --> 00:15:03,600
to the environment we would expect it

379
00:15:07,350 --> 00:15:05,600
everywhere or whether we think that's

380
00:15:08,710 --> 00:15:07,360
just a rare event

381
00:15:10,710 --> 00:15:08,720
in that case

382
00:15:13,030 --> 00:15:10,720
we've actually seen endosymbiosis

383
00:15:15,990 --> 00:15:13,040
several times so maybe it is something

384
00:15:20,790 --> 00:15:19,110
11. how does modularity influence

385
00:15:22,870 --> 00:15:20,800
organization at multiple levels of

386
00:15:24,829 --> 00:15:22,880
biology and should we expect a similar

387
00:15:27,829 --> 00:15:24,839
modular structure in

388
00:15:32,389 --> 00:15:27,839
non-terrestrial life i think that's

389
00:15:38,069 --> 00:15:33,590
and that just brings us to our

390
00:15:40,870 --> 00:15:39,269
so you can

391
00:15:43,189 --> 00:15:40,880
plug into those

392
00:15:44,150 --> 00:15:43,199
discussions those webinars if you would

393
00:15:46,310 --> 00:15:44,160
like

394
00:15:54,710 --> 00:15:46,320
and that is my summary of what we came

395
00:16:00,069 --> 00:15:56,629
i just wanted to make sure my mic was

396
00:16:02,629 --> 00:16:00,079
open f uh thank you lucas um

397
00:16:05,110 --> 00:16:02,639
all right so uh looks do you want to

398
00:16:08,310 --> 00:16:05,120
come back to the question that bob

399
00:16:24,949 --> 00:16:08,320
raised just at the start only thoughts

400
00:16:29,590 --> 00:16:27,110
yes i think we definitely want to

401
00:16:30,389 --> 00:16:29,600
consider this question of

402
00:16:33,990 --> 00:16:30,399
um

403
00:16:36,550 --> 00:16:34,000
information storage of some kind and

404
00:16:39,509 --> 00:16:36,560
whether that information is necessarily

405
00:16:41,990 --> 00:16:39,519
going to be stored in dna or a similar

406
00:16:43,350 --> 00:16:42,000
molecule or contingently

407
00:16:45,030 --> 00:16:43,360
i know

408
00:16:47,430 --> 00:16:45,040
steve banner has

409
00:16:50,230 --> 00:16:47,440
published some things on

410
00:16:52,310 --> 00:16:50,240
the use of carbon whether we necessarily

411
00:16:55,030 --> 00:16:52,320
are looking for carbon molecules because

412
00:16:58,470 --> 00:16:55,040
they seem to be able to

413
00:16:59,590 --> 00:16:58,480
operate in more ways uh for more complex

414
00:17:01,269 --> 00:16:59,600
structures

415
00:17:03,509 --> 00:17:01,279
than other things

416
00:17:05,669 --> 00:17:03,519
uh bob is there anything else you'd like

417
00:17:07,990 --> 00:17:05,679
to anywhere else you'd like to run with

418
00:17:10,390 --> 00:17:08,000
that question

419
00:17:12,470 --> 00:17:10,400
yes can you hear me

420
00:17:13,350 --> 00:17:12,480
yes we can

421
00:17:15,270 --> 00:17:13,360
um

422
00:17:18,870 --> 00:17:15,280
basically uh

423
00:17:20,789 --> 00:17:18,880
my point is that if

424
00:17:23,829 --> 00:17:20,799
say mars life

425
00:17:27,270 --> 00:17:23,839
had gone into suspended animation

426
00:17:29,909 --> 00:17:27,280
because of the conditions deteriorating

427
00:17:30,870 --> 00:17:29,919
on the surface of the planet

428
00:17:33,669 --> 00:17:30,880
then

429
00:17:35,990 --> 00:17:33,679
there would be no activity other than

430
00:17:38,710 --> 00:17:36,000
the fact that these

431
00:17:39,669 --> 00:17:38,720
creatures have some kind of memory

432
00:17:44,830 --> 00:17:39,679
now

433
00:17:47,510 --> 00:17:44,840
mit and harvard are developing this dna

434
00:17:50,150 --> 00:17:47,520
detector that they hope will fly on a

435
00:17:52,950 --> 00:17:50,160
future mars mission

436
00:17:56,230 --> 00:17:52,960
but if these aliens

437
00:17:58,070 --> 00:17:56,240
have a different memory storage

438
00:18:01,029 --> 00:17:58,080
than dna

439
00:18:03,590 --> 00:18:01,039
then how would we detect

440
00:18:09,110 --> 00:18:03,600
these aliens that are in suspended

441
00:18:14,150 --> 00:18:11,750
i think that has to be uh

442
00:18:16,470 --> 00:18:14,160
necessary i think that has to be an

443
00:18:18,630 --> 00:18:16,480
important part of research

444
00:18:20,870 --> 00:18:18,640
for the future uh

445
00:18:23,350 --> 00:18:20,880
for me that's one of the big take-home

446
00:18:24,310 --> 00:18:23,360
messages uh from this question

447
00:18:26,150 --> 00:18:24,320
is

448
00:18:27,830 --> 00:18:26,160
what sorts of things are we looking for

449
00:18:29,430 --> 00:18:27,840
and why do we think that they will be

450
00:18:31,510 --> 00:18:29,440
necessary

451
00:18:33,909 --> 00:18:31,520
personally i find

452
00:18:35,990 --> 00:18:33,919
the quest the idea that dna is necessary

453
00:18:38,710 --> 00:18:36,000
for all life in the universe

454
00:18:40,549 --> 00:18:38,720
uh highly problematic i would expect

455
00:18:41,669 --> 00:18:40,559
some other kind of information storage

456
00:18:43,430 --> 00:18:41,679
molecule

457
00:18:44,950 --> 00:18:43,440
but i do think that the information

458
00:18:47,270 --> 00:18:44,960
storage molecule is going to have to

459
00:18:49,510 --> 00:18:47,280
have some

460
00:18:50,870 --> 00:18:49,520
property of organization

461
00:18:53,029 --> 00:18:50,880
uh some

462
00:18:56,710 --> 00:18:53,039
information content

463
00:18:59,110 --> 00:18:56,720
that might be discernible i'm still

464
00:19:02,789 --> 00:18:59,120
fuzzy on what that would be

465
00:19:04,310 --> 00:19:02,799
um if there's perhaps some an entropic

466
00:19:07,430 --> 00:19:04,320
there we go repeating sequence of

467
00:19:08,390 --> 00:19:07,440
certain molecules from kelly lane

468
00:19:11,750 --> 00:19:08,400
yes

469
00:19:14,310 --> 00:19:11,760
some level of repetition which is

470
00:19:15,669 --> 00:19:14,320
higher than we would expect from abiotic

471
00:19:18,549 --> 00:19:15,679
sources

472
00:19:22,230 --> 00:19:18,559
and yet not completely random

473
00:19:26,310 --> 00:19:23,990
presumably the ultimate answer will be

474
00:19:29,669 --> 00:19:26,320
graphene because the unfortunate

475
00:19:32,470 --> 00:19:29,679
everything is graphene at the moment um

476
00:19:35,270 --> 00:19:32,480
other other questions you're welcome to

477
00:19:37,830 --> 00:19:35,280
type them in uh the phone lines are

478
00:19:39,669 --> 00:19:37,840
actually open so if you just take

479
00:19:41,510 --> 00:19:39,679
yourself off mute

480
00:19:43,110 --> 00:19:41,520
we're only a small group so i'm not

481
00:19:44,789 --> 00:19:43,120
going to suggest that you have to raise

482
00:19:47,110 --> 00:19:44,799
your hands but

483
00:19:50,310 --> 00:19:47,120
other thoughts or questions particularly

484
00:19:52,070 --> 00:19:50,320
because anything that you add here

485
00:19:54,470 --> 00:19:52,080
and in the document afterwards can help

486
00:19:58,150 --> 00:19:54,480
the group uh improve their documents as

487
00:20:00,870 --> 00:19:58,160
we're moving them towards uh a more uh a

488
00:20:02,630 --> 00:20:00,880
broader publication on that so

489
00:20:22,150 --> 00:20:02,640
other thoughts or questions that people

490
00:20:25,669 --> 00:20:23,750
for a moment this takes me back to when

491
00:20:29,510 --> 00:20:25,679
i used to teach nba classes when you

492
00:20:33,590 --> 00:20:31,430
but i shan't

493
00:20:35,830 --> 00:20:33,600
i'm going to throw a question out there

494
00:20:38,630 --> 00:20:35,840
that's maybe a little bit more specific

495
00:20:40,870 --> 00:20:38,640
uh hopefully it will get things rolling

496
00:20:43,990 --> 00:20:40,880
what do you think are

497
00:20:45,430 --> 00:20:44,000
perhaps universal traits of life on

498
00:20:46,390 --> 00:20:45,440
earth

499
00:20:49,510 --> 00:20:46,400
that we

500
00:20:50,789 --> 00:20:49,520
might consider dna is certainly one

501
00:20:52,710 --> 00:20:50,799
that's been

502
00:20:54,230 --> 00:20:52,720
thrown out there already are there

503
00:21:15,590 --> 00:20:54,240
others

504
00:21:15,600 --> 00:21:18,390
hello

505
00:21:22,950 --> 00:21:20,789
yep go right ahead

506
00:21:25,190 --> 00:21:22,960
hi i i

507
00:21:26,789 --> 00:21:25,200
my hands got faster than my brain on

508
00:21:28,950 --> 00:21:26,799
what i typed

509
00:21:30,630 --> 00:21:28,960
basically

510
00:21:33,029 --> 00:21:30,640
may be other mechanisms

511
00:21:34,870 --> 00:21:33,039
for uh memory storage or information

512
00:21:35,830 --> 00:21:34,880
storage out there that we don't know

513
00:21:36,789 --> 00:21:35,840
about

514
00:21:39,270 --> 00:21:36,799
uh

515
00:21:41,909 --> 00:21:39,280
but we do know about dna here on earth

516
00:21:43,990 --> 00:21:41,919
uh but what we don't know about mars is

517
00:21:46,549 --> 00:21:44,000
whether there's any organic material in

518
00:21:48,710 --> 00:21:46,559
the sediments at all

519
00:21:50,390 --> 00:21:48,720
that has not been established as yet

520
00:21:51,990 --> 00:21:50,400
and that would be a big discovery if it

521
00:21:53,270 --> 00:21:52,000
happens

522
00:21:55,430 --> 00:21:53,280
and

523
00:21:57,909 --> 00:21:55,440
to characterize the organics if they are

524
00:21:59,750 --> 00:21:57,919
found would be the next step and to see

525
00:22:02,630 --> 00:21:59,760
if there are any structures that are

526
00:22:04,149 --> 00:22:02,640
reminiscent of life such as in organic

527
00:22:08,270 --> 00:22:04,159
geochemistry

528
00:22:11,270 --> 00:22:08,280
and you know dna would be wonderful but

529
00:22:12,950 --> 00:22:11,280
i think it's reasonable that

530
00:22:14,710 --> 00:22:12,960
other other things might be out there

531
00:22:16,470 --> 00:22:14,720
but i have no clue as to

532
00:22:22,549 --> 00:22:16,480
what we should look for beyond dna at

533
00:22:22,559 --> 00:24:10,470
i will go mute thank you

534
00:24:12,230 --> 00:24:11,350
system

535
00:24:14,789 --> 00:24:12,240
um

536
00:24:16,950 --> 00:24:14,799
and i think both of those uh once again

537
00:24:18,710 --> 00:24:16,960
return us to this dna question

538
00:24:21,830 --> 00:24:18,720
uh it would be

539
00:24:23,830 --> 00:24:21,840
lovely to find dna because it is

540
00:24:25,190 --> 00:24:23,840
unambiguously

541
00:24:27,269 --> 00:24:25,200
uh

542
00:24:29,029 --> 00:24:27,279
informative

543
00:24:30,830 --> 00:24:29,039
but it's sort of unclear what else would

544
00:24:32,549 --> 00:24:30,840
be unambiguously

545
00:24:33,909 --> 00:24:32,559
informative

546
00:24:36,390 --> 00:24:33,919
and i think

547
00:24:39,029 --> 00:24:36,400
a real benefit of the line of research

548
00:24:41,909 --> 00:24:39,039
uh presented under this head is rather

549
00:24:44,070 --> 00:24:41,919
than ask the open-ended question what is

550
00:24:45,830 --> 00:24:44,080
there out there that we might find

551
00:24:47,990 --> 00:24:45,840
it's asking the question what's common

552
00:24:49,510 --> 00:24:48,000
to all life on earth and is there some

553
00:24:53,430 --> 00:24:49,520
reason we should expect it would be

554
00:24:58,310 --> 00:24:55,590
um

555
00:25:00,149 --> 00:24:58,320
so perhaps there is some aspect of

556
00:25:01,430 --> 00:25:00,159
metabolism that we expect to be

557
00:25:03,269 --> 00:25:01,440
universal

558
00:25:05,269 --> 00:25:03,279
information storage is there but hard to

559
00:25:08,789 --> 00:25:05,279
detect

560
00:25:12,070 --> 00:25:08,799
scavenging perhaps scavenging of

561
00:25:18,230 --> 00:25:15,510
radicals uh electrons protons

562
00:25:19,830 --> 00:25:18,240
can we think of some way we might

563
00:25:22,070 --> 00:25:19,840
characterize

564
00:25:43,269 --> 00:25:22,080
removing those from the environment that

565
00:25:47,350 --> 00:25:45,350
bob if it's easier for you to speak

566
00:25:49,190 --> 00:25:47,360
rather than type you're welcome to do

567
00:26:24,710 --> 00:25:49,200
that as applies to everyone else of

568
00:26:24,720 --> 00:26:29,510
it's ron again hi

569
00:26:33,590 --> 00:26:31,510
i'm getting a delay on i'm hearing back

570
00:26:36,230 --> 00:26:33,600
from you guys on my system

571
00:26:41,350 --> 00:26:39,830
detecting that macromolecules uh such as

572
00:26:43,430 --> 00:26:41,360
dna

573
00:26:45,990 --> 00:26:43,440
would be wonderful but

574
00:26:47,669 --> 00:26:46,000
that's an a priori assumption that

575
00:26:49,590 --> 00:26:47,679
whatever is out there is going to be our

576
00:26:52,390 --> 00:26:49,600
model system

577
00:26:54,630 --> 00:26:52,400
uh detection of metabolic activity would

578
00:26:56,950 --> 00:26:54,640
be wonderful

579
00:26:58,630 --> 00:26:56,960
but that's hard the viking experiments

580
00:27:01,190 --> 00:26:58,640
were

581
00:27:04,390 --> 00:27:01,200
not so easy to interpret and they all

582
00:27:06,390 --> 00:27:04,400
leaned in the negative area

583
00:27:07,909 --> 00:27:06,400
that you have to make an assumption that

584
00:27:09,990 --> 00:27:07,919
what you're giving them to eat will be

585
00:27:11,269 --> 00:27:10,000
metabolized that's hard enough to do

586
00:27:12,149 --> 00:27:11,279
here on earth

587
00:27:15,269 --> 00:27:12,159
uh

588
00:27:16,549 --> 00:27:15,279
let alone a system that we

589
00:27:19,510 --> 00:27:16,559
are dubious with if there is

590
00:27:21,110 --> 00:27:19,520
microorganisms in the soil

591
00:27:23,669 --> 00:27:21,120
one thing i don't think has been

592
00:27:26,310 --> 00:27:23,679
particularly well explored is the use of

593
00:27:27,190 --> 00:27:26,320
stable isotope fractionation

594
00:27:29,110 --> 00:27:27,200
uh

595
00:27:31,909 --> 00:27:29,120
to detect products

596
00:27:33,990 --> 00:27:31,919
that have been formed by reactants

597
00:27:35,669 --> 00:27:34,000
that already exist in the system we are

598
00:27:36,710 --> 00:27:35,679
going to study

599
00:27:41,190 --> 00:27:36,720
so

600
00:27:42,789 --> 00:27:41,200
is very well known on earth the best

601
00:27:47,110 --> 00:27:42,799
example being

602
00:27:52,870 --> 00:27:50,390
behind methane that's enriched to nc13

603
00:27:54,070 --> 00:27:52,880
and co2 that's well enriched in carbon

604
00:27:56,630 --> 00:27:54,080
12

605
00:27:58,149 --> 00:27:56,640
as very very clear signals for

606
00:28:00,070 --> 00:27:58,159
biological

607
00:28:03,029 --> 00:28:00,080
methane oxidation as well as methane

608
00:28:05,909 --> 00:28:03,039
production

609
00:28:07,669 --> 00:28:05,919
the advantage of something like that

610
00:28:09,990 --> 00:28:07,679
is

611
00:28:12,470 --> 00:28:10,000
in easily measure

612
00:28:13,350 --> 00:28:12,480
the stable isotopes that are that are

613
00:28:15,590 --> 00:28:13,360
given

614
00:28:17,110 --> 00:28:15,600
for say a hydrocarbon in the system once

615
00:28:18,549 --> 00:28:17,120
you know they are there

616
00:28:20,149 --> 00:28:18,559
and to look at

617
00:28:21,669 --> 00:28:20,159
potential products

618
00:28:23,029 --> 00:28:21,679
uh to see if they are enriched in the

619
00:28:25,990 --> 00:28:23,039
lighter isotope that would be a

620
00:28:28,149 --> 00:28:26,000
signature for the presence of life

621
00:28:31,029 --> 00:28:28,159
uh on an uh

622
00:28:33,269 --> 00:28:31,039
an extraterrestrial body

623
00:28:35,909 --> 00:28:33,279
i'm thinking specifically of perhaps

624
00:28:38,230 --> 00:28:35,919
titan or enceladus

625
00:28:40,789 --> 00:28:38,240
and maybe the metabolism of

626
00:28:43,909 --> 00:28:40,799
acetylene

627
00:28:45,190 --> 00:28:43,919
to acetate my biological systems could

628
00:28:47,750 --> 00:28:45,200
enrich

629
00:28:49,909 --> 00:28:47,760
uh acetate and carbon-12 relative to the

630
00:28:51,990 --> 00:28:49,919
starting acetylene

631
00:28:54,310 --> 00:28:52,000
and that would allow you to say yes

632
00:28:56,389 --> 00:28:54,320
there's life there based on what we know

633
00:28:59,750 --> 00:28:56,399
occurs in in terrestrial anaerobic

634
00:29:00,789 --> 00:28:59,760
systems for that metabolize acetylene

635
00:29:02,310 --> 00:29:00,799
and we wouldn't have to do any

636
00:29:03,750 --> 00:29:02,320
incubation experiments we can just

637
00:29:04,950 --> 00:29:03,760
collect the stuff

638
00:29:06,389 --> 00:29:04,960
anyway

639
00:29:08,310 --> 00:29:06,399
that's just an example i'm sure there

640
00:29:09,990 --> 00:29:08,320
are better ones than what i came up with

641
00:29:12,070 --> 00:29:10,000
but

642
00:29:13,110 --> 00:29:12,080
it eliminates

643
00:29:15,510 --> 00:29:13,120
the

644
00:29:17,430 --> 00:29:15,520
difficulty of conducting a metabolic

645
00:29:19,990 --> 00:29:17,440
experiment ella viking

646
00:29:22,230 --> 00:29:20,000
as well as a priori looking for

647
00:29:24,029 --> 00:29:22,240
something like dna

648
00:29:25,430 --> 00:29:24,039
and then having to rule out

649
00:29:27,750 --> 00:29:25,440
unequivocally that it's not

650
00:29:31,269 --> 00:29:27,760
contamination by one of the guys at jpl

651
00:29:33,909 --> 00:29:31,279
who sneezed into the collectivism anyway

652
00:29:38,789 --> 00:29:33,919
that's all i have to say

653
00:29:43,669 --> 00:29:41,029
lucas do you want to pick up bob's

654
00:29:51,590 --> 00:29:43,679
question as well that he's just typed

655
00:29:57,430 --> 00:29:54,070
so bob is asking this question of uh

656
00:29:59,510 --> 00:29:57,440
organic carbon deposition and whether

657
00:30:00,870 --> 00:29:59,520
carbon is going to survive in certain

658
00:30:03,350 --> 00:30:00,880
environments

659
00:30:05,350 --> 00:30:03,360
uh again i think one of the central

660
00:30:07,350 --> 00:30:05,360
questions we have to deal with i would

661
00:30:08,470 --> 00:30:07,360
perhaps take a step back and ask the

662
00:30:11,990 --> 00:30:08,480
people here

663
00:30:13,750 --> 00:30:12,000
do you think carbon is necessarily

664
00:30:16,149 --> 00:30:13,760
what we're looking for so when i say

665
00:30:17,430 --> 00:30:16,159
organic chemistry i mean carbon-based

666
00:30:20,870 --> 00:30:17,440
chemistry

667
00:30:22,389 --> 00:30:20,880
we always looking for carbon-based

668
00:30:23,750 --> 00:30:22,399
chemistry or

669
00:30:25,750 --> 00:30:23,760
um

670
00:30:27,269 --> 00:30:25,760
are we imagining something like silicon

671
00:30:29,269 --> 00:30:27,279
deep in the

672
00:30:31,029 --> 00:30:29,279
clouds of jupiter where the pressure is

673
00:30:33,669 --> 00:30:31,039
high enough perhaps to make a

674
00:30:35,350 --> 00:30:33,679
silicon-based uh information storage

675
00:30:52,389 --> 00:30:35,360
molecule possible

676
00:31:12,310 --> 00:30:54,310
and the sound of deep thinking could be

677
00:31:17,029 --> 00:31:14,789
mike how hard it would be to just uh

678
00:31:18,870 --> 00:31:17,039
pull up a quick survey

679
00:31:21,269 --> 00:31:18,880
uh that way we can

680
00:31:23,510 --> 00:31:21,279
poke people a little bit to commit to

681
00:31:24,950 --> 00:31:23,520
whether they think carbon is a good

682
00:31:29,029 --> 00:31:24,960
foundation

683
00:31:30,710 --> 00:31:29,039
not

684
00:31:35,029 --> 00:31:30,720
we could do that so just a yes no

685
00:31:40,310 --> 00:31:38,149
is the question is is carbon

686
00:31:42,549 --> 00:31:40,320
is carbon a necessary

687
00:31:46,549 --> 00:31:42,559
feature of life

688
00:31:53,350 --> 00:31:49,990
how about a yes uh no and uh

689
00:31:55,350 --> 00:31:53,360
you wanna possibly or not sure option

690
00:32:17,350 --> 00:31:55,360
uh no i wanna make people commit to yes

691
00:32:20,389 --> 00:32:18,630
okay and uh just so you know all you

692
00:32:31,990 --> 00:32:20,399
have to do is select an option to cast

693
00:32:32,000 --> 00:32:54,830
so andy and mike you guys

694
00:32:59,590 --> 00:32:57,909
six mike i saw your lips moving and i

695
00:33:00,789 --> 00:32:59,600
heard something but i didn't get words

696
00:33:20,549 --> 00:33:00,799
out of that

697
00:33:20,559 --> 00:33:31,190
okay

698
00:33:35,509 --> 00:33:34,310
i love it when we get uh 50 50 results

699
00:33:38,710 --> 00:33:35,519
here

700
00:33:41,350 --> 00:33:38,720
had

701
00:33:43,830 --> 00:33:41,360
perhaps someone who thinks that uh

702
00:33:46,950 --> 00:33:43,840
there is no non-carbon-based life would

703
00:34:13,430 --> 00:33:46,960
like to speak up on why they think

704
00:34:13,440 --> 00:34:58,150
uh

705
00:35:02,630 --> 00:35:00,069
i think paulie sums it up pretty nicely

706
00:35:05,910 --> 00:35:02,640
he says we know only one kind of life

707
00:35:08,150 --> 00:35:05,920
can we make conclusions uh certainly

708
00:35:09,270 --> 00:35:08,160
i would say from a philosophical

709
00:35:11,589 --> 00:35:09,280
standpoint

710
00:35:13,349 --> 00:35:11,599
uh going from n equals one your

711
00:35:15,430 --> 00:35:13,359
confidence in your conclusions is going

712
00:35:17,670 --> 00:35:15,440
to be fairly weak

713
00:35:19,510 --> 00:35:17,680
nonetheless we have a task that

714
00:35:21,670 --> 00:35:19,520
theoretically we wish to complete which

715
00:35:23,670 --> 00:35:21,680
is the search for life elsewhere

716
00:35:26,870 --> 00:35:23,680
uh well complete might not be the right

717
00:35:28,069 --> 00:35:26,880
word an endeavor we pursue

718
00:35:29,510 --> 00:35:28,079
uh

719
00:35:32,310 --> 00:35:29,520
so i would maintain that some

720
00:35:33,829 --> 00:35:32,320
operational definition of life for

721
00:35:35,750 --> 00:35:33,839
um

722
00:35:39,430 --> 00:35:35,760
trying to think of the exact words that

723
00:35:41,750 --> 00:35:39,440
uh cleland and shaiba use in the article

724
00:35:43,910 --> 00:35:41,760
in planets and life but we need a

725
00:36:29,990 --> 00:35:43,920
testable

726
00:36:34,630 --> 00:36:32,630
i agree with with ron's comment uh

727
00:36:36,310 --> 00:36:34,640
i'm having trouble imagining anything

728
00:36:38,630 --> 00:36:36,320
other than carbon working and since i

729
00:36:41,270 --> 00:36:38,640
know carbon works at least once

730
00:36:43,589 --> 00:36:41,280
that seems a strong case for it possibly

731
00:36:46,870 --> 00:36:43,599
working somewhere else uh it's hard to

732
00:36:49,910 --> 00:36:46,880
imagine a strong case for something else

733
00:36:52,310 --> 00:36:49,920
uh i flirt with nitrogen on occasion

734
00:37:09,270 --> 00:36:52,320
but uh

735
00:37:13,109 --> 00:37:11,349
yay we have a universal feature of life

736
00:37:14,310 --> 00:37:13,119
or at least one that no one's willing to

737
00:37:15,910 --> 00:37:14,320
uh

738
00:37:18,069 --> 00:37:15,920
argue against at the moment so we're

739
00:37:20,710 --> 00:37:18,079
looking for carbon

740
00:37:23,829 --> 00:37:20,720
uh what else

741
00:37:25,589 --> 00:37:23,839
how about liquid water

742
00:37:28,230 --> 00:37:25,599
let's uh

743
00:37:29,990 --> 00:37:28,240
mike let's go for another poll here

744
00:38:17,109 --> 00:37:30,000
about the liquid water unnecessary

745
00:38:19,990 --> 00:38:18,470
okay

746
00:38:22,470 --> 00:38:20,000
it looks like

747
00:38:24,550 --> 00:38:22,480
we have one person who's claiming

748
00:38:27,510 --> 00:38:24,560
that uh liquid water is a necessary

749
00:38:28,710 --> 00:38:27,520
condition of life i think that's the

750
00:38:32,390 --> 00:38:28,720
um

751
00:38:34,710 --> 00:38:32,400
carbon

752
00:38:38,310 --> 00:38:34,720
so who would like to defend

753
00:38:40,230 --> 00:38:38,320
another uh presumably another solvent

754
00:38:41,349 --> 00:38:40,240
for life

755
00:38:44,790 --> 00:38:41,359
yep

756
00:38:51,589 --> 00:38:46,550
who wants to propose an alternative

757
00:38:54,630 --> 00:38:52,790
uh

758
00:38:56,710 --> 00:38:54,640
can you hear me

759
00:38:59,589 --> 00:38:56,720
yes

760
00:39:01,349 --> 00:38:59,599
it's been proposed on titan that

761
00:39:03,750 --> 00:39:01,359
methane uh

762
00:39:05,829 --> 00:39:03,760
and ethane might serve as uh

763
00:39:06,790 --> 00:39:05,839
solvents for life

764
00:39:08,710 --> 00:39:06,800
but

765
00:39:12,069 --> 00:39:08,720
since there there's a hydrologic cycle

766
00:39:13,510 --> 00:39:12,079
on on titan based on those hydrocarbons

767
00:39:16,150 --> 00:39:13,520
and there's a lot of good things that

768
00:39:19,670 --> 00:39:16,160
could dissolve into it and uh

769
00:39:23,430 --> 00:39:19,680
sustain an analog of life as we know it

770
00:39:25,270 --> 00:39:23,440
albeit at extremely low temperatures

771
00:39:26,390 --> 00:39:25,280
whether it's true or not is is another

772
00:39:28,790 --> 00:39:26,400
story but

773
00:39:31,829 --> 00:39:28,800
uh hypothetically speaking yeah it could

774
00:39:37,910 --> 00:39:31,839
probably work chris mckay is uh

775
00:39:42,630 --> 00:39:40,710
do we know what range of temperature

776
00:39:43,670 --> 00:39:42,640
uh and pressure

777
00:39:45,589 --> 00:39:43,680
uh

778
00:39:49,589 --> 00:39:45,599
me saying methane and combinations

779
00:39:51,750 --> 00:39:49,599
thereof would be liquid under

780
00:39:54,310 --> 00:39:51,760
it's what about uh

781
00:39:56,550 --> 00:39:54,320
90 degrees kelvin and it's roughly about

782
00:40:00,470 --> 00:39:56,560
twice the atmosphere of

783
00:40:03,030 --> 00:40:00,480
the atmospheric pressure of uh earth

784
00:40:05,190 --> 00:40:03,040
very cold and and some high pressure but

785
00:40:06,310 --> 00:40:05,200
not not excessive

786
00:40:08,630 --> 00:40:06,320
right now i'm

787
00:40:12,150 --> 00:40:08,640
not just um

788
00:40:14,470 --> 00:40:12,160
tighten the question is um

789
00:40:17,430 --> 00:40:14,480
the question is how broad the range of

790
00:40:19,829 --> 00:40:17,440
temperatures it stays liquid under one

791
00:40:21,349 --> 00:40:19,839
of the benefits of water is we have this

792
00:40:24,630 --> 00:40:21,359
large range

793
00:40:26,630 --> 00:40:24,640
of 100 kelvin

794
00:40:29,030 --> 00:40:26,640
through which it stays liquid

795
00:40:30,950 --> 00:40:29,040
and the question is whether our

796
00:40:35,589 --> 00:40:30,960
methane ethane mix

797
00:40:35,599 --> 00:40:45,030
good point i don't know of hand

798
00:40:50,069 --> 00:40:47,030
that's definitely a great option anyone

799
00:41:24,870 --> 00:40:50,079
want to propose another option

800
00:41:28,150 --> 00:41:26,309
all right well we

801
00:41:29,990 --> 00:41:28,160
was there a comment there

802
00:41:33,109 --> 00:41:30,000
no actually lucas i was just i was just

803
00:41:34,470 --> 00:41:33,119
going to suggest that uh at this point

804
00:41:37,510 --> 00:41:34,480
unless there are

805
00:41:39,990 --> 00:41:37,520
any other questions or ideas that people

806
00:41:42,390 --> 00:41:40,000
want to chip in we might draw it to a

807
00:41:45,190 --> 00:41:42,400
close on the understanding but uh what

808
00:41:46,870 --> 00:41:45,200
the team really need is for you to dig

809
00:41:49,589 --> 00:41:46,880
into the document so if you just give us

810
00:41:52,069 --> 00:41:49,599
a few minutes just to flip the switch

811
00:41:53,910 --> 00:41:52,079
and start putting in your comments just

812
00:41:56,710 --> 00:41:53,920
in case anyone hasn't done this or

813
00:41:58,309 --> 00:41:56,720
anyone's watching uh this later and

814
00:42:01,190 --> 00:41:58,319
hasn't done it

815
00:42:04,069 --> 00:42:01,200
we're asking you to log into your google

816
00:42:06,230 --> 00:42:04,079
account just so we can see who is

817
00:42:08,069 --> 00:42:06,240
writing which comments in case the

818
00:42:09,190 --> 00:42:08,079
authors need to follow it up with you

819
00:42:11,109 --> 00:42:09,200
afterwards

820
00:42:13,190 --> 00:42:11,119
and the commenting process is terribly

821
00:42:15,670 --> 00:42:13,200
simple you highlight a block of text you

822
00:42:17,750 --> 00:42:15,680
right click and choose add comment and

823
00:42:19,109 --> 00:42:17,760
you get a little post-it note pop-up at

824
00:42:21,349 --> 00:42:19,119
the side

825
00:42:22,630 --> 00:42:21,359
and that's how we're collecting people's

826
00:42:23,430 --> 00:42:22,640
thoughts on that

827
00:42:25,430 --> 00:42:23,440
so

828
00:42:27,430 --> 00:42:25,440
having said that lucas thank you very

829
00:42:31,030 --> 00:42:27,440
much appreciate that we appreciate all

830
00:42:33,750 --> 00:42:31,040
the input from uh everyone out there and

831
00:42:35,750 --> 00:42:33,760
we will now go and change the status of

832
00:42:37,990 --> 00:42:35,760
the document and see you all in a

833
00:42:39,829 --> 00:42:38,000
different format um