Martin Hanczyc: The line between life and not-life

148,205 views ・ 2011-11-07

TED


請雙擊下方英文字幕播放視頻。

譯者: Kevin Hung 審譯者: Ana Choi
00:15
So historically there has
0
15260
2000
在過去,
00:17
been a huge divide between what people
1
17260
3000
有一個很大的鴻溝界於人,
00:20
consider to be non-living systems on one
2
20260
3000
認為非生命系統的這一邊
00:23
side, and living systems on the other side.
3
23260
2000
和生命系統的另外一邊。
00:25
So we go from, say, this beautiful and
4
25260
2000
我們從這個美麗
00:27
complex crystal as non-life, and this rather
5
27260
3000
且複雜的非生命晶體,然後到
00:30
beautiful and complex cat on the other side.
6
30260
3000
另一邊美麗且複雜的貓。
00:33
Over the last hundred and fifty years or so,
7
33260
3000
過去的一百五十年左右,
00:36
science has kind of blurred this distinction
8
36260
2000
科學家模糊了這樣
00:38
between non-living and living systems, and
9
38260
2000
在於非生命與生命系統之間的界限,
00:40
now we consider that there may be a kind
10
40260
2000
現在我們認為有一種
00:42
of continuum that exists between the two.
11
42260
3000
在於這二者之間的連續變化。
00:45
We'll just take one example here:
12
45260
2000
我們先來看看這個例子:
00:47
a virus is a natural system, right?
13
47260
2000
一個病毒是一個自然系統,對嗎?
00:49
But it's very simple. It's very simplistic.
14
49260
2000
但是它非常簡單,它太過簡單了。
00:51
It doesn't really satisfy all the requirements,
15
51260
2000
它無法完全滿足所有的需求。
00:53
it doesn't have all the characteristics
16
53260
2000
它沒有生命系統的
00:55
of living systems and is in fact a parasite
17
55260
2000
所有特質,而事實上它是寄生
00:57
on other living systems in order to, say,
18
57260
3000
在其他生命系統上來
01:00
reproduce and evolve.
19
60260
2000
繁殖和演化。
01:02
But what we're going to be talking about here
20
62260
2000
但是我們今晚將要在這裡
01:04
tonight are experiments done on this sort of
21
64260
2000
討論的是在非生命這部份
01:06
non-living end of this spectrum -- so actually
22
66260
2000
所作的實驗,實際上
01:08
doing chemical experiments in the laboratory,
23
68260
3000
在實驗室裡所做的化學實驗
01:11
mixing together nonliving ingredients
24
71260
2000
混合了非生命的成分
01:13
to make new structures, and that these
25
73260
2000
產生了新的結構,而且這些
01:15
new structures might have some of the
26
75260
2000
新的結構也許有些
01:17
characteristics of living systems.
27
77260
2000
生命系統的特性。
01:19
Really what I'm talking about here is
28
79260
2000
我在這裡所要說的是
01:21
trying to create a kind of artificial life.
29
81260
2000
試著創造一種新的人造生命。
01:23
So what are these characteristics that I'm
30
83260
2000
那麼在我剛剛所談到的
01:25
talking about? These are them.
31
85260
2000
有什麼特性呢?它們是如下:
01:27
We consider first that life has a body.
32
87260
2000
我們首先認為生命是有一個身體。
01:29
Now this is necessary to distinguish the self
33
89260
2000
現在有必要把個體從環境中
01:31
from the environment.
34
91260
2000
區分出來。
01:33
Life also has a metabolism. Now this is a
35
93260
2000
生命會新陳代謝,現在這是一個
01:35
process by which life can convert resources
36
95260
3000
生命轉換的過程,從環境中
01:38
from the environment into building blocks
37
98260
2000
的元素到構成要素,
01:40
so it can maintain and build itself.
38
100260
3000
它可以維護並建造本身。
01:43
Life also has a kind of inheritable information.
39
103260
2000
生命有繼承的資訊。
01:45
Now we, as humans, we store our information
40
105260
2000
我們人類現在,在基因裡的DNA
01:47
as DNA in our genomes and we pass this
41
107260
3000
儲存資訊,然後傳遞
01:50
information on to our offspring.
42
110260
2000
這些訊息給我們的子孫。
01:52
If we couple the first two -- the body and the metabolism --
43
112260
2000
假如我們連結這二個--身體及代謝--
01:54
we can come up with a system that could
44
114260
2000
我們可以得到一個可以移動
01:56
perhaps move and replicate, and if we
45
116260
2000
且複製的系統,假如我們
01:58
coupled these now to inheritable information,
46
118260
3000
連結這些來繼承資訊,
02:01
we can come up with a system that would be
47
121260
2000
我們可以得到一個系統,那是
02:03
more lifelike, and would perhaps evolve.
48
123260
2000
更像是生命的,也許可以進化。
02:05
And so these are the things we will try to do
49
125260
2000
這是我們將要試著
02:07
in the lab, make some experiments that have
50
127260
2000
在實驗室裡做的,做出一些實驗可
02:09
one or more of these characteristics of life.
51
129260
3000
有一個或多個特性的生命。
02:12
So how do we do this? Well, we use
52
132260
2000
我們如何辦到呢?我們使用
02:14
a model system that we term a protocell.
53
134260
2000
一個模型系統,我們稱之為原生細胞。
02:16
You might think of this as kind of like a
54
136260
2000
你可以想像這個東西像是一個
02:18
primitive cell. It is a simple chemical
55
138260
2000
原始的細胞,他是一個活細胞的
02:20
model of a living cell, and if you consider
56
140260
3000
簡單化學模型,你可以把他看成
02:23
for example a cell in your body may have
57
143260
2000
一個細胞,在你的身體裡也許有
02:25
on the order of millions of different types
58
145260
2000
不同類型的百萬個
02:27
of molecules that need to come together,
59
147260
2000
分子需要組成在一塊,
02:29
play together in a complex network
60
149260
2000
組成一個複雜的網絡
02:31
to produce something that we call alive.
61
151260
3000
來產生我們賴以維生的東西。
02:34
In the laboratory what we want to do
62
154260
2000
在實驗室裡,我們要做的
02:36
is much the same, but with on the order of
63
156260
2000
就是像這樣,但是十種
02:38
tens of different types of molecules --
64
158260
2000
不同分子的順序--
02:40
so a drastic reduction in complexity, but still
65
160260
2000
在複雜度上是大幅減少,但仍
02:42
trying to produce something that looks lifelike.
66
162260
3000
要產生像是真的生命型態。
02:45
And so what we do is, we start simple
67
165260
2000
所以我們這樣做,我們開始
02:47
and we work our way up to living systems.
68
167260
3000
用自己的方式產生生命系統。
02:50
Consider for a moment this quote by
69
170260
2000
考慮一下這句在
02:52
Leduc, a hundred years ago, considering a
70
172260
2000
一百多年前的話,勒度克認為
02:54
kind of synthetic biology:
71
174260
2000
合成生物學:
02:56
"The synthesis of life, should it ever occur,
72
176260
2000
「生命的組成,應該是不斷發生,
02:58
will not be the sensational discovery which we
73
178260
2000
不會有令人興奮的事情被發現,
03:00
usually associate with the idea."
74
180260
2000
因我們已認為是這樣 。」
03:02
That's his first statement. So if we actually
75
182260
2000
這是他第一個聲明,如果我們真的
03:04
create life in the laboratories, it's
76
184260
2000
在實驗室裡創造了生命,
03:06
probably not going to impact our lives at all.
77
186260
2000
也許也不會對我們的生命造成衝擊。
03:08
"If we accept the theory of evolution, then
78
188260
2000
「假如我們接受進化論,
03:10
the first dawn of synthesis of life must consist
79
190260
2000
合成生命的曙光一定
03:12
in the production of forms intermediate
80
192260
2000
在生產過程中,
03:14
between the inorganic and the organic
81
194260
2000
從無機到有機體
03:16
world, or between the non-living
82
196260
2000
的世界,或是從非生命
03:18
and living world, forms which possess
83
198260
2000
到生命世界,產生
03:20
only some of the rudimentary attributes of life"
84
200260
2000
只有生命的一些基本特性」
03:22
-- so, the ones I just discussed --
85
202260
2000
所以,這個是我剛提到的
03:24
"to which other attributes will be slowly added
86
204260
2000
「會慢慢的增加其他特性
03:26
in the course of development by the
87
206260
2000
在這個發展過程
03:28
evolutionary actions of the environment."
88
208260
2000
與環境互動的演化」。
03:30
So we start simple, we make some structures
89
210260
2000
所以我們開始製做一些簡單的結構,
03:32
that may have some of these characteristics
90
212260
2000
一些有生命的特性,
03:34
of life, and then we try to develop that
91
214260
2000
而且我們試著發展
03:36
to become more lifelike.
92
216260
2000
令到可以更像是生命。
03:38
This is how we can start to make a protocell.
93
218260
2000
這是我們開始製做一個原生細胞的方法。
03:40
We use this idea called self-assembly.
94
220260
2000
我們用一個叫做自我組合的觀點。
03:42
What that means is, I can mix some
95
222260
2000
意思是說,我可以在我的實驗室
03:44
chemicals together in a test tube in my lab,
96
224260
2000
結合一些化學物質,
03:46
and these chemicals will start to self-associate
97
226260
2000
這些化學物質會開始自我聯合
03:48
to form larger and larger structures.
98
228260
2000
變成大一點的結構。
03:50
So say on the order of tens of thousands,
99
230260
2000
依此順序,從幾萬到
03:52
hundreds of thousands of molecules will
100
232260
2000
幾十萬的分子會
03:54
come together to form a large structure
101
234260
2000
組合在一起形成一個從未
03:56
that didn't exist before.
102
236260
2000
存在過的大型結構。
03:58
And in this particular example,
103
238260
2000
在這個例子中,
04:00
what I took is some membrane molecules,
104
240260
2000
我將一些膜分子
04:02
mixed those together in the right environment,
105
242260
2000
混合在這個環境中,
04:04
and within seconds it forms these rather
106
244260
2000
在短時間內,它就形成了
04:06
complex and beautiful structures here.
107
246260
2000
複雜且漂亮的結構。
04:08
These membranes are also quite similar,
108
248260
2000
在形態和功能上
04:10
morphologically and functionally,
109
250260
2000
這些膜相當類似
04:12
to the membranes in your body,
110
252260
2000
你身體裡的膜,
04:14
and we can use these, as they say,
111
254260
2000
我們可以使用這些
04:16
to form the body of our protocell.
112
256260
2000
來形成原生細胞的主體。
04:18
Likewise,
113
258260
1000
就像
04:19
we can work with oil and water systems.
114
259260
2000
我們可以在油和水的系統中作業。
04:21
As you know, when you put oil and water together,
115
261260
2000
你知道,當你把油和水放在一起,
04:23
they don't mix, but through self-assembly
116
263260
2000
他們不會混合,但經過組裝
04:25
we can get a nice oil droplet to form,
117
265260
2000
我們可以得到一個油滴液,
04:27
and we can actually use this as a body for
118
267260
2000
我們可以用這個當一個主體
04:29
our artificial organism or for our protocell,
119
269260
2000
做為人工有機體或是原生細胞,
04:31
as you will see later.
120
271260
2000
你等一下會看到。
04:33
So that's just forming some body stuff, right?
121
273260
2000
這是剛成型的身體,對嗎?
04:35
Some architectures.
122
275260
2000
一些架構。
04:37
What about the other aspects of living systems?
123
277260
2000
在生命系統的其他方面會是如何?
04:39
So we came up with this protocell model here
124
279260
2000
所以我們想出了原生細胞的模型,
04:41
that I'm showing.
125
281260
2000
我現在顯示出來。
04:43
We started with a natural occurring clay
126
283260
2000
我們開始用天然的粘土
04:45
called montmorillonite.
127
285260
2000
叫做蒙脫石。
04:47
This is natural from the environment, this clay.
128
287260
2000
存在於天然的環境中,這種粘土
04:49
It forms a surface that is, say, chemically active.
129
289260
2000
會形成一個表面,這是化學活性。
04:51
It could run a metabolism on it.
130
291260
2000
它會執行代謝程序。
04:53
Certain kind of molecules like to associate
131
293260
2000
這個粘土喜歡與某種
04:55
with the clay. For example, in this case, RNA, shown in red
132
295260
2000
分子相連,舉例來說,像紅色的 RNA--
04:57
-- this is a relative of DNA,
133
297260
2000
這是相對的 DNA,
04:59
it's an informational molecule --
134
299260
2000
這是帶有訊息的分子--
05:01
it can come along and it starts to associate
135
301260
2000
它開始是單獨的,然後與其他
05:03
with the surface of this clay.
136
303260
2000
粘土表面相連。
05:05
This structure, then, can organize the
137
305260
2000
這個結構,可以組成
05:07
formation of a membrane boundary around
138
307260
2000
一個膜邊來圍繞著
05:09
itself, so it can make a body of
139
309260
2000
自身,可以變為液態
05:11
liquid molecules around itself, and that's
140
311260
2000
分子的主體圍繞自己,這個
05:13
shown in green here on this micrograph.
141
313260
2000
綠色的是顯微照片。
05:15
So just through self-assembly, mixing things
142
315260
2000
剛剛透過自行組裝,在實驗室裡
05:17
together in the lab, we can come up with, say,
143
317260
3000
混合在一起,我們可以說
05:20
a metabolic surface with some
144
320260
2000
一個代謝的表面與一些
05:22
informational molecules attached
145
322260
2000
訊息分子在這個
05:24
inside of this membrane body, right?
146
324260
2000
膜的主體裡面,對嗎?
05:26
So we're on a road towards living systems.
147
326260
4000
所以我們已走向生命系統的路上。
05:30
But if you saw this protocell, you would not
148
330260
2000
但假如你看到這個原生細胞,你不會
05:32
confuse this with something that was actually alive.
149
332260
2000
和其他的真實生命混淆。
05:34
It's actually quite lifeless. Once it forms,
150
334260
2000
它真的是沒有生命,它一旦成形,
05:36
it doesn't really do anything.
151
336260
2000
便沒有辦法做任何事。
05:38
So, something is missing.
152
338260
2000
所以,一定是有東西漏掉了。
05:40
Some things are missing.
153
340260
2000
有一些東西是漏掉了。
05:42
So some things that are missing is,
154
342260
2000
一些漏掉的東西是,
05:44
for example, if you had a flow of energy
155
344260
2000
舉例來說,如果你有一道能量
05:46
through a system, what we'd want
156
346260
2000
貫穿一個系統,我們想要
05:48
is a protocell that can harvest
157
348260
2000
一個原生細胞可以獲得
05:50
some of that energy in order to maintain itself,
158
350260
2000
一些能量來維持自身,
05:52
much like living systems do.
159
352260
2000
就像生命系統所做的一樣。
05:54
So we came up with a different protocell
160
354260
2000
我們想出了一個不一樣的原生細胞
05:56
model, and this is actually simpler than the previous one.
161
356260
2000
模型,這個比先前一個更簡單。
05:58
In this protocell model, it's just an oil droplet,
162
358260
2000
在這個原生細胞模型中,這只是一個油滴,
06:00
but a chemical metabolism inside
163
360260
2000
但有個化學代謝在裡頭,
06:02
that allows this protocell to use energy
164
362260
2000
可以讓原生細胞可以使用能源
06:04
to do something, to actually become dynamic,
165
364260
3000
來做一些事情,變成動態的,
06:07
as we'll see here.
166
367260
2000
像我們看到。
06:09
You add the droplet to the system.
167
369260
2000
你在這個系統加入這個油滴。
06:11
It's a pool of water, and the protocell
168
371260
2000
這是個水池,這個原生細胞
06:13
starts moving itself around in the system.
169
373260
2000
在這個系統開始自己移動起來。
06:15
Okay? Oil droplet forms
170
375260
2000
OK ? 油滴形成
06:17
through self-assembly, has a chemical
171
377260
2000
透過自我組合,有一個化學
06:19
metabolism inside so it can use energy,
172
379260
2000
代謝在這裡頭,它可以使用能量,
06:21
and it uses that energy to move itself
173
381260
2000
它用這些能量讓自己
06:23
around in its environment.
174
383260
2000
在這個環境裡移動。
06:25
As we heard earlier, movement is very
175
385260
2000
先前我們聽過,動作在這類
06:27
important in these kinds of living systems.
176
387260
2000
的生命系統中是非常重要的。
06:29
It is moving around, exploring its environment,
177
389260
2000
它到處移動,探索這個環境,
06:31
and remodeling its environment, as you see,
178
391260
2000
且重新塑造它的環境,如你所看到的,
06:33
by these chemical waves that are forming by the protocell.
179
393260
2000
原生細胞所產生的這些化學波。
06:35
So it's acting, in a sense, like a living system
180
395260
2000
它在動,某種意義,像是一個生命系統
06:37
trying to preserve itself.
181
397260
3000
試著維護本身。
06:40
We take this same moving protocell here,
182
400260
3000
我們帶了一樣會動的原生細胞,
06:43
and we put it in another experiment,
183
403260
2000
放在另一個實驗裡,
06:45
get it moving. Then I'm going
184
405260
2000
讓它動。然後我
06:47
to add some food to the system,
185
407260
2000
加入一些食物在系統裡面,
06:49
and you'll see that in blue here, right?
186
409260
3000
你看到這個藍色的,對不對?
06:52
So I add some food source to the system.
187
412260
2000
我加入一些食物在這個系統裡。
06:54
The protocell moves. It encounters the food.
188
414260
2000
原生細胞移動了,它遇到了食物。
06:56
It reconfigures itself and actually then
189
416260
2000
它重新調整了自己,然後
06:58
is able to climb to the highest concentration
190
418260
2000
爬上系統中濃度最高
07:00
of food in that system and stop there.
191
420260
2000
的食物,然後停留在那裡。
07:02
Alright? So not only do we have this system
192
422260
2000
對嗎?我們不只有一個系統
07:04
that has a body, it has a metabolism,
193
424260
2000
像一個身體,它還有代謝,
07:06
it can use energy, it moves around.
194
426260
3000
它可以使用能量來移動。
07:09
It can sense its local environment
195
429260
2000
它會感測到周圍的環境
07:11
and actually find resources
196
431260
2000
並在其中找到
07:13
in the environment to sustain itself.
197
433260
2000
資源來維生。
07:15
Now, this doesn't have a brain, it doesn't have
198
435260
2000
現在,它還沒有大腦,它沒有
07:17
a neural system. This is just a sack of
199
437260
2000
神經系統,這只是一群
07:19
chemicals that is able to have this interesting
200
439260
2000
化學品的集合,有這些有趣
07:21
and complex lifelike behavior.
201
441260
2000
且像生命的複雜行為。
07:23
If we count the number of chemicals
202
443260
2000
假如我們算一下這系統內
07:25
in that system, actually, including the water
203
445260
2000
的化學物,包含了在盤子裡
07:27
that's in the dish, we have five chemicals
204
447260
2000
的水,我們有5 個化學物質
07:29
that can do this.
205
449260
2000
可以完成這個。
07:31
So then we put these protocells together in a
206
451260
2000
接著, 我們將這些原生細胞放在
07:33
single experiment to see what they would do,
207
453260
2000
一個獨立的實驗中,觀察它們所做的,
07:35
and depending on the conditions, we have
208
455260
2000
依照這些條件,我們有
07:37
some protocells on the left that are
209
457260
2000
一些原生細胞在左邊
07:39
moving around and it likes to touch the other
210
459260
2000
往來移動著,像是要去碰這個
07:41
structures in its environment.
211
461260
2000
環境下的其他結構。
07:43
On the other hand we have two moving
212
463260
2000
另一邊我們有二個移動的,
07:45
protocells that like to circle each other,
213
465260
2000
各自成圈圈的原生細胞,
07:47
and they form a kind of a dance, a complex dance with each other.
214
467260
2000
它們開始一種舞蹈,互相做複雜的舞蹈。
07:49
Right? So not only do individual protocells
215
469260
2000
對嗎?不只是單獨的原生細胞
07:51
have behavior, what we've interpreted as
216
471260
2000
有行為,我們的解釋是
07:53
behavior in this system, but we also have
217
473260
2000
這個系統中的行為,我們有
07:55
basically population-level behavior
218
475260
3000
一個基本的人口水平行為,
07:58
similar to what organisms have.
219
478260
3000
類似生物所擁有的。
08:01
So now that you're all experts on protocells,
220
481260
3000
現在你們已是原生細胞的專家,
08:04
we're going to play a game with these protocells.
221
484260
2000
我們要和這些原生細胞玩個遊戲。
08:06
We're going to make two different kinds.
222
486260
2000
我們要做兩種不一樣的類型。
08:08
Protocell A has a certain kind of chemistry
223
488260
3000
原生細胞 A 有一種化學成分在
08:11
inside that, when activated, the protocell
224
491260
2000
裡面,當活躍時,這個原生細胞
08:13
starts to vibrate around, just dancing.
225
493260
2000
會開始在周圍動來動去,像在跳舞。
08:15
So remember, these are primitive things,
226
495260
2000
所以請記住,這些是原始的舉動,
08:17
so dancing protocells, that's very
227
497260
2000
這些跳舞的原生細胞,它們對
08:19
interesting to us. (Laughter)
228
499260
2000
我們是非常的有趣。 ( 笑聲 )
08:21
The second protocell has a different
229
501260
2000
第二個原生細胞有一個不一樣的
08:23
chemistry inside, and when activated,
230
503260
2000
化學成份在裡頭,當活躍時
08:25
the protocells all come together and they fuse
231
505260
2000
原生細胞會融合在一起
08:27
into one big one. Right?
232
507260
2000
變成一大個,對嗎?
08:29
And we just put these two together
233
509260
2000
我們把這兩個放在
08:31
in the same system.
234
511260
2000
同一個系統裡。
08:33
So there's population A,
235
513260
2000
這是人口A,
08:35
there's population B, and then
236
515260
2000
這是人口B,
08:37
we activate the system,
237
517260
2000
我們啟動這個系統,
08:39
and protocell Bs, they're the blue ones,
238
519260
2000
原生細胞Bs , 它們是藍色的,
08:41
they all come together. They fuse together
239
521260
2000
全部組合成一塊。融合在一起
08:43
to form one big blob, and the other protocell
240
523260
2000
形成一個大的滴夜,而其他的原生細胞
08:45
just dances around. And this just happens
241
525260
2000
在周圍跳舞。這發生在
08:47
until all of the energy in the system is
242
527260
2000
這個系統中,直到這些能源
08:49
basically used up, and then, game over.
243
529260
3000
被用完為止,然後,遊戲結束。
08:52
So then I repeated this experiment
244
532260
2000
當我重覆這個實驗
08:54
a bunch of times, and one time
245
534260
2000
很多次後,有一次
08:56
something very interesting happened.
246
536260
2000
有趣的事發生了。
08:58
So, I added these protocells together
247
538260
2000
我將這些原生細胞放在
09:00
to the system, and protocell A and protocell B
248
540260
2000
這個系統裡,原生細胞 A 和 原生細胞 B
09:02
fused together to form a hybrid protocell AB.
249
542260
2000
融合成一個混合的原生細胞 AB。
09:04
That didn't happen before. There it goes.
250
544260
2000
這在以前從未發生,現在發生了。
09:06
There's a protocell AB now in this system.
251
546260
3000
現在有了原生細胞 AB 在這個系統內。
09:09
Protocell AB likes to dance around for a bit,
252
549260
3000
當原生細胞B 要做融合時,
09:12
while protocell B does the fusing, okay?
253
552260
3000
原生細胞 AB 喜歡到處跳舞,OK?
09:15
But then something even more interesting happens.
254
555260
3000
但是更有趣的事情發生了。
09:18
Watch when these two large protocells,
255
558260
2000
看一下這兩個大的原生細胞,
09:20
the hybrid ones, fuse together.
256
560260
2000
這個混合的,融合在一起。
09:22
Now we have a dancing protocell
257
562260
3000
現在我們有一個跳舞的原生細胞
09:25
and a self-replication event. Right. (Laughter)
258
565260
4000
和一個自我分裂的事件,對嗎。 ( 笑聲 )
09:29
Just with blobs of chemicals, again.
259
569260
2000
就是和化學點滴
09:31
So the way this works is, you have
260
571260
2000
這個方法可行,你有
09:33
a simple system of five chemicals here,
261
573260
2000
一個簡單的系統,內有5個化學物質,
09:35
a simple system here. When they hybridize,
262
575260
2000
一個簡單的系統,當它們混合時,
09:37
you then form something that's different than
263
577260
2000
你就創造出與原先不一樣的東西,
09:39
before, it's more complex than before,
264
579260
2000
較之前的複雜得多,
09:41
and you get the emergence of another kind of
265
581260
2000
你也得到另一種類似生命
09:43
lifelike behavior which
266
583260
2000
行為的東西,
09:45
in this case is replication.
267
585260
2000
在這個情況下複製。
09:47
So since we can make some interesting
268
587260
2000
既然我們可以製作我們感到
09:49
protocells that we like, interesting colors and
269
589260
2000
有趣的原生細胞,那麼有趣的顏色和
09:51
interesting behaviors, and they're very easy
270
591260
2000
有趣的行為,它們都可以很容易
09:53
to make, and they have interesting lifelike
271
593260
2000
的製造出,而且它們擁有像生命行為
09:55
properties, perhaps these protocells have
272
595260
3000
的有趣特性,也許這些原生細胞可以
09:58
something to tell us about the origin of life
273
598260
2000
告訴我們在有關地球上生命
10:00
on the Earth. Perhaps these represent an
274
600260
2000
的起源,也許這展示一個
10:02
easily accessible step, one of the first steps
275
602260
2000
較容易的一個步驟,第一步邁向
10:04
by which life got started on the early Earth.
276
604260
3000
地球的生命是如何開始的。
10:07
Certainly, there were molecules present on
277
607260
2000
肯定的是,這些是早期在地球上
10:09
the early Earth, but they wouldn't have been
278
609260
2000
存在的分子,但是它們沒有像
10:11
these pure compounds that we worked with
279
611260
2000
這些純化合物,這些我們在實驗室
10:13
in the lab and I showed in these experiments.
280
613260
2000
所做出來的,剛給各位看的實驗。
10:15
Rather, they'd be a real complex mixture of
281
615260
2000
而它們是真正複雜的
10:17
all kinds of stuff, because
282
617260
2000
各類混合物,因為
10:19
uncontrolled chemical reactions produce
283
619260
2000
無法控制的化學反應產生
10:21
a diverse mixture of organic compounds.
284
621260
2000
不同的有機化合物的混合物。
10:23
Think of it like a primordial ooze, okay?
285
623260
3000
想像它是一個原始軟泥,好嗎?
10:26
And it's a pool that's too difficult to fully
286
626260
2000
這是一個池塘,太難以充分表現,
10:28
characterize, even by modern methods, and
287
628260
2000
即使用現代的方法,
10:30
the product looks brown, like this tar here
288
630260
2000
這個看起來棕色,像是焦油
10:32
on the left. A pure compound
289
632260
2000
在左邊。一個純化合物
10:34
is shown on the right, for contrast.
290
634260
2000
在右邊,做個對比。
10:36
So this is similar to what happens when you
291
636260
2000
這個情形就好像當你
10:38
take pure sugar crystals in your kitchen,
292
638260
2000
在廚房使用純糖晶體,
10:40
you put them in a pan, and you apply energy.
293
640260
2000
你放在鍋子裡,然後給他們能量。
10:42
You turn up the heat, you start making
294
642260
2000
你把他們加熱,你開始製造
10:44
or breaking chemical bonds in the sugar,
295
644260
2000
或斷掉糖裡的化學鍵,
10:46
forming a brownish caramel, right?
296
646260
2000
形成了褐色的焦糖,對嗎?
10:48
If you let that go unregulated, you'll
297
648260
2000
假如你管制的放任它們,你會
10:50
continue to make and break chemical bonds,
298
650260
2000
繼續製造和斷掉化學鍵,
10:52
forming an even more diverse mixture of
299
652260
2000
形成多樣化的混合物
10:54
molecules that then forms this kind of black
300
654260
2000
分子,最後形成這種黑色的
10:56
tarry stuff in your pan, right, that's
301
656260
2000
柏油樣的東西在鍋底,對嗎?這是
10:58
difficult to wash out. So that's what
302
658260
2000
非常難以清洗的,這也許是
11:00
the origin of life would have looked like.
303
660260
2000
生命開始時所呈現的樣子。
11:02
You needed to get life out of this junk that
304
662260
2000
4億,4億5千萬年前,
11:04
is present on the early Earth,
305
664260
2000
在早期的地球, 你需要從
11:06
four, 4.5 billion years ago.
306
666260
2000
這樣的垃圾中淬取出生命。
11:08
So the challenge then is,
307
668260
2000
所以,這個挑戰是,
11:10
throw away all your pure chemicals in the lab,
308
670260
2000
要把你在實驗室裡的純化合物丟開,
11:12
and try to make some protocells with lifelike
309
672260
2000
試著從這種原始軟泥,製造出
11:14
properties from this kind of primordial ooze.
310
674260
3000
類似生命特性的原生細胞。
11:17
So we're able to then see the self-assembly
311
677260
2000
我們可以看到這些油滴
11:19
of these oil droplet bodies again
312
679260
2000
再次的自我組合,
11:21
that we've seen previously,
313
681260
2000
像先前所看到的,
11:23
and the black spots inside of there
314
683260
2000
其中這個黑色的
11:25
represent this kind of black tar -- this diverse,
315
685260
2000
代表這種黑色焦油,這個多元
11:27
very complex, organic black tar.
316
687260
2000
複雜的有機黑色焦油。
11:29
And we put them into one of these
317
689260
2000
我們將它放入其中的一個
11:31
experiments, as you've seen earlier, and then
318
691260
2000
實驗中,像之前看到的,然後
11:33
we watch lively movement that comes out.
319
693260
2000
我們看到它活潑的移動它
11:35
They look really good, very nice movement,
320
695260
2000
它們看起來很好,非常好的運動,
11:37
and also they appear to have some kind of
321
697260
2000
它們也呈現出某種行為,
11:39
behavior where they kind of circle
322
699260
2000
他們互相繞圈圈,
11:41
around each other and follow each other,
323
701260
3000
而且跟著其他的繞
11:44
similar to what we've seen before -- but again,
324
704260
2000
和我們前面看到的很像,但是
11:46
working with just primordial conditions,
325
706260
2000
這是在原始的條件下,
11:48
no pure chemicals.
326
708260
2000
不是純化合物。
11:50
These are also, these tar-fueled protocells,
327
710260
2000
這是焦油原生細胞,也是
11:52
are also able to locate resources
328
712260
2000
可以在它們的環境
11:54
in their environment.
329
714260
1000
中找到資源。
11:55
I'm going to add some resource from the left,
330
715260
2000
我想從左邊加入一些資源
11:57
here, that defuses into the system,
331
717260
2000
擴散到這個系統裡,
11:59
and you can see, they really like that.
332
719260
2000
你可以看到,它們非常喜歡。
12:01
They become very energetic, and able
333
721260
2000
它們變得有活力,而且
12:03
to find the resource in the environment,
334
723260
2000
能夠在這個環境中找到資源,
12:05
similar to what we saw before.
335
725260
2000
像我們之前所看到的那樣。
12:07
But again, these are done in these primordial
336
727260
2000
但是,它們是在原始的條件下,
12:09
conditions, really messy conditions,
337
729260
2000
真正很差的環境下,
12:11
not sort of sterile laboratory conditions.
338
731260
2000
不是在那種無菌的實驗室裡。
12:13
These are very dirty little protocells,
339
733260
2000
它們是事實上是骯髒的
12:15
as a matter of fact. (Laughter)
340
735260
2000
小原生細胞。 (笑聲)
12:17
But they have lifelike properties, is the point.
341
737260
3000
但重點是,它們有生命類的特性。
12:20
So, doing these artificial life experiments
342
740260
3000
所以,做這些人工生命的實驗
12:23
helps us define a potential path between
343
743260
3000
幫助我們定義介於生命與
12:26
non-living and living systems.
344
746260
3000
非生命的一條路,
12:29
And not only that, but it helps us
345
749260
2000
不只是這樣,它還幫助我們
12:31
broaden our view of what life is
346
751260
2000
開拓我們對生命的視野,
12:33
and what possible life there could be
347
753260
2000
還有外太空生命
12:35
out there -- life that could be very different
348
755260
2000
的可能性 -- 生命也許和我們在
12:37
from life that we find here on Earth.
349
757260
3000
地球上發現的生命很不一樣。
12:40
And that leads me to the next
350
760260
2000
這引發了我下一期
12:42
term, which is "weird life."
351
762260
2000
「奇特的生命」。
12:44
This is a term by Steve Benner.
352
764260
3000
這一期由史帝夫班納主導。
12:47
This is used in reference to a report
353
767260
2000
這是在 2007 年的報告,
12:49
in 2007 by the National Research Council
354
769260
2000
美國國家研究
12:51
in the United States, wherein
355
771260
2000
理事會被引用,
12:53
they tried to understand how we can
356
773260
2000
他們試著了解,為什麼我們
12:55
look for life elsewhere in the universe, okay,
357
775260
2000
可以在太空中尋找生命,
12:57
especially if that life is very different from life
358
777260
2000
尤其是對地球而言是非常不同的
12:59
on Earth. If we went to another planet and
359
779260
3000
生命型態。假如我們去我們認為在那裡
13:02
we thought there might be life there,
360
782260
2000
或許有生命的不同星球,
13:04
how could we even recognize it as life?
361
784260
2000
我們是如何判定它是有生命的呢?
13:06
Well, they came up with three very general
362
786260
2000
他們想出三種判定的標準,
13:08
criteria. First is -- and they're listed here.
363
788260
2000
這是他們列出來的。
13:10
The first is, the system has to be in
364
790260
2000
第一,這個系統必須是
13:12
non-equilibrium. That means the system
365
792260
2000
非平衡的。 意思是
13:14
cannot be dead, in a matter of fact.
366
794260
1000
事實上,不是已死掉。
13:15
Basically what that means is, you have
367
795260
2000
基本上,意思是它是有
13:17
an input of energy into the system that life
368
797260
2000
一個能量,輸入到這個系統,
13:19
can use and exploit to maintain itself.
369
799260
3000
這個生命可以使用且被利用來維持自身。
13:22
This is similar to having the Sun shining
370
802260
2000
這就好像是有個太陽在地球
13:24
on the Earth, driving photosynthesis,
371
804260
2000
上照亮,來行使光合作用
13:26
driving the ecosystem.
372
806260
2000
驅動生態系統。
13:28
Without the Sun, there's likely to be
373
808260
2000
沒有太陽,就沒有
13:30
no life on this planet.
374
810260
2000
生命在這個星球上。
13:32
Secondly, life needs to be in liquid form,
375
812260
2000
第二,生命需是液態狀的,
13:34
so that means even if we had some
376
814260
2000
這個表示假如我們有
13:36
interesting structures, interesting molecules
377
816260
2000
一些有趣的結構,有趣的分子
13:38
together but they were frozen solid,
378
818260
2000
結合在一起,但它們是凍成固態的,
13:40
then this is not a good place for life.
379
820260
2000
這不是一個適合生命的地方。
13:42
And thirdly, we need to be able to make
380
822260
2000
第三,我們需要可以製造
13:44
and break chemical bonds. And again
381
824260
2000
和切斷化學鍵。而且
13:46
this is important because life transforms
382
826260
2000
這是非常重要的,因為生命
13:48
resources from the environment into
383
828260
2000
從環境中的資源轉換到
13:50
building blocks so it can maintain itself.
384
830260
2000
建構的機體,以至它可以維持下去。
13:52
Now today, I told you about very strange
385
832260
2000
現在,我所說的這個非常奇特
13:54
and weird protocells -- some that contain clay,
386
834260
2000
且怪異的原生細胞,有一些包含了粘土,
13:56
some that have primordial ooze in them,
387
836260
3000
有一些當中有原始的軟泥,
13:59
some that have basically oil
388
839260
2000
在它們裡面有一些有基本的油,
14:01
instead of water inside of them.
389
841260
2000
而不是水。
14:03
Most of these don't contain DNA,
390
843260
2000
它們大部分都沒有 DNA,
14:05
but yet they have lifelike properties.
391
845260
2000
但是它們有類似生命的特性。
14:07
But these protocells satisfy
392
847260
3000
這些原生細胞符合
14:10
these general requirements of living systems.
393
850260
3000
這些生命系統的一般要素。
14:13
So by making these chemical, artificial
394
853260
2000
藉著製造這些化學,人工的
14:15
life experiments, we hope not only
395
855260
2000
生命經驗,我們希望不只是
14:17
to understand something fundamental
396
857260
2000
了解關於生命起源的
14:19
about the origin of life and the existence
397
859260
2000
基本原理和這個星球
14:21
of life on this planet, but also
398
861260
2000
上的生命,同時
14:23
what possible life there could be
399
863260
2000
生命也可能離開這裡
14:25
out there in the universe. Thank you.
400
865260
3000
去到宇宙,謝謝。
14:28
(Applause)
401
868260
4000
(掌聲)
關於本網站

本網站將向您介紹對學習英語有用的 YouTube 視頻。 您將看到來自世界各地的一流教師教授的英語課程。 雙擊每個視頻頁面上顯示的英文字幕,從那裡播放視頻。 字幕與視頻播放同步滾動。 如果您有任何意見或要求,請使用此聯繫表與我們聯繫。

https://forms.gle/WvT1wiN1qDtmnspy7