Michael Archer: How we'll resurrect the gastric brooding frog, the Tasmanian tiger

51,204 views

2013-06-27 ・ TED


New videos

Michael Archer: How we'll resurrect the gastric brooding frog, the Tasmanian tiger

51,204 views ・ 2013-06-27

TED


Please double-click on the English subtitles below to play the video.

00:00
Translator: Joseph Geni Reviewer: Morton Bast
0
0
7000
00:12
I do want to test this question we're all interested in:
1
12840
2936
00:15
Does extinction have to be forever?
2
15800
3016
00:18
I'm focused on two projects I want to tell you about.
3
18840
2696
00:21
One is the Thylacine Project.
4
21560
1816
00:23
The other one is the Lazarus Project,
5
23400
1762
00:25
and that's focused on the gastric-brooding frog.
6
25186
2710
00:27
And it would be a fair question to ask,
7
27920
1896
00:29
why have we focused on these two animals?
8
29840
2256
00:32
Well, point number one, each of them represents a unique family of its own.
9
32120
5376
00:37
We've lost a whole family.
10
37520
1576
00:39
That's a big chunk of the global genome gone.
11
39120
2616
00:41
I'd like it back.
12
41760
1576
00:43
The second reason is that we killed these things.
13
43360
4336
00:47
In the case of the thylacine, regrettably, we shot every one that we saw.
14
47720
4936
00:52
We slaughtered them.
15
52680
1436
00:54
In the case of the gastric-brooding frog, we may have "fungicided" it to death.
16
54600
5096
00:59
There's a dreadful fungus that's moving through the world
17
59720
2696
01:02
that's called the chytrid fungus,
18
62440
1616
01:04
and it's nailing frogs all over the world.
19
64080
2216
01:06
We think that's probably what got this frog,
20
66320
2048
01:08
and humans are spreading this fungus.
21
68392
2384
01:10
And this introduces a very important ethical point,
22
70800
2856
01:13
and I think you will have heard this many times
23
73680
2216
01:15
when this topic comes up.
24
75920
1616
01:17
What I think is important
25
77560
1736
01:19
is that, if it's clear that we exterminated these species,
26
79320
3576
01:22
then I think we not only have a moral obligation
27
82920
3416
01:26
to see what we can do about it,
28
86360
1477
01:27
but I think we've got a moral imperative to try to do something, if we can.
29
87861
4150
01:32
OK. Let me talk to you about the Lazarus Project.
30
92720
2856
01:35
It's a frog. And you think, frog.
31
95600
2856
01:38
Yeah, but this was not just any frog.
32
98480
3376
01:41
Unlike a normal frog, which lays its eggs in the water
33
101880
2776
01:44
and goes away and wishes its froglets well,
34
104680
2656
01:47
this frog swallowed its fertilized eggs,
35
107360
3616
01:51
swallowed them into the stomach, where it should be having food,
36
111000
3656
01:54
didn't digest the eggs, and turned its stomach into a uterus.
37
114680
4496
01:59
In the stomach, the eggs went on to develop into tadpoles,
38
119200
3336
02:02
and in the stomach, the tadpoles went on to develop into frogs,
39
122560
3856
02:06
and they grew in the stomach
40
126440
1656
02:08
until eventually the poor old frog was at risk of bursting apart.
41
128120
4016
02:12
It has a little cough and a hiccup, and out comes sprays of little frogs.
42
132160
4056
02:16
Now, when biologists saw this, they were agog.
43
136240
2736
02:19
They thought, this is incredible.
44
139000
1936
02:20
No animal, let alone a frog, has been known to do this,
45
140960
3816
02:24
to change one organ in the body into another.
46
144800
2136
02:26
And you can imagine the medical world went nuts over this as well.
47
146960
3816
02:30
If we could understand
48
150800
1216
02:32
how that frog is managing the way its tummy works,
49
152040
3296
02:35
is there information here that we need to understand
50
155360
2456
02:37
or could usefully use to help ourselves?
51
157840
3336
02:41
Now, I'm not suggesting we want to raise our babies in our stomach,
52
161200
3336
02:44
but I am suggesting it's possible
53
164560
1616
02:46
we might want to manage gastric secretion in the gut.
54
166200
2656
02:48
And just as everybody got excited about it, bang!
55
168880
2816
02:51
It was extinct.
56
171720
1200
02:54
I called up my friend,
57
174120
1456
02:55
Professor Mike Tyler in the University of Adelaide.
58
175600
2381
02:58
He was the last person who had this frog, a colony of these things, in his lab.
59
178005
4371
03:02
And I said, "Mike, by any chance --" This was 30 or 40 years ago.
60
182400
3048
03:05
"By any chance had you kept any frozen tissue of this frog?"
61
185472
3744
03:09
And he thought about it,
62
189240
1216
03:10
and he went to his deep freezer, minus 20 degrees centigrade,
63
190480
3816
03:14
and he poured through everything in the freezer,
64
194320
2256
03:16
and there in the bottom was a jar and it contained tissues of these frogs.
65
196600
4296
03:20
This was very exciting,
66
200920
1256
03:22
but there was no reason why we should expect that this would work,
67
202200
3336
03:25
because this tissue had not had any antifreeze put in it,
68
205560
3936
03:29
cryoprotectants, to look after it when it was frozen.
69
209520
3656
03:33
And normally, when water freezes, as you know, it expands,
70
213200
2736
03:35
and the same thing happens in a cell.
71
215960
1816
03:37
If you freeze tissues, the water expands, damages or bursts the cell walls.
72
217800
4376
03:42
Well, we looked at the tissue under the microscope.
73
222200
2416
03:44
It actually didn't look bad. The cell walls looked intact.
74
224640
2736
03:47
So we thought, let's give it a go.
75
227400
1626
03:49
What we did is something called somatic cell nuclear transplantation.
76
229480
4256
03:53
We took the eggs of a related species, a living frog,
77
233760
3616
03:57
and we inactivated the nucleus of the egg.
78
237400
2856
04:00
We used ultraviolet radiation to do that.
79
240280
2416
04:02
And then we took the dead nucleus from the dead tissue of the extinct frog
80
242720
4736
04:07
and we inserted those nuclei into that egg.
81
247480
3096
04:10
Now, by rights, this is kind of like a cloning project,
82
250600
3456
04:14
like what produced Dolly,
83
254080
1216
04:15
but it's actually very different,
84
255320
1616
04:16
because Dolly was live sheep into live sheep cells.
85
256960
2736
04:19
That was a miracle, but it was workable.
86
259720
2336
04:22
What we're trying to do is take a dead nucleus from an extinct species
87
262080
3656
04:25
and put it into a completely different species and expect that to work.
88
265760
3376
04:29
Well, we had no real reason to expect it would,
89
269160
2296
04:31
and we tried hundreds and hundreds of these.
90
271480
2650
04:34
And just last February, the last time we did these trials,
91
274800
2776
04:37
I saw a miracle starting to happen.
92
277600
2840
04:41
What we found was most of these eggs didn't work,
93
281040
3296
04:44
but then suddenly, one of them began to divide.
94
284360
2976
04:47
That was so exciting.
95
287360
1376
04:48
And then the egg divided again. And then again.
96
288760
2896
04:51
And pretty soon, we had early-stage embryos
97
291680
3016
04:54
with hundreds of cells forming those.
98
294720
2776
04:57
We even DNA-tested some of these cells,
99
297520
2776
05:00
and the DNA of the extinct frog is in those cells.
100
300320
3816
05:04
So we're very excited. This is not a tadpole. It's not a frog.
101
304160
3496
05:07
But it's a long way along the journey
102
307680
2736
05:10
to producing, or bringing back, an extinct species.
103
310440
2816
05:13
And this is news.
104
313280
1216
05:14
We haven't announced this publicly before.
105
314520
2456
05:17
We're excited.
106
317000
1216
05:18
We've got to get past this point.
107
318240
1616
05:19
We now want this ball of cells to start to gastrulate,
108
319880
2524
05:22
to turn in so that it will produce the other tissues.
109
322428
2628
05:25
It'll go on and produce a tadpole and then a frog.
110
325080
3696
05:28
Watch this space.
111
328800
1216
05:30
I think we're going to have this frog hopping
112
330040
2193
05:32
glad to be back in the world again.
113
332257
1719
05:34
(Applause)
114
334720
1816
05:36
Thank you.
115
336560
1206
05:37
(Applause)
116
337790
2106
05:39
We haven't done it yet, but keep the applause ready.
117
339920
2658
05:43
The second project I want to talk to you about is the Thylacine Project.
118
343080
3976
05:47
The thylacine looks a bit, to most people, like a dog,
119
347080
3856
05:50
or maybe like a tiger, because it has stripes.
120
350960
2143
05:53
But it's not related to any of those. It's a marsupial.
121
353127
2809
05:55
It raised its young in a pouch, like a koala or a kangaroo would do,
122
355960
4176
06:00
and it has a long history, a long, fascinating history,
123
360160
5016
06:05
that goes back 25 million years.
124
365200
2896
06:08
But it's also a tragic history.
125
368120
1615
06:10
The first one that we see occurs in the ancient rain forests of Australia
126
370200
4936
06:15
about 25 million years ago,
127
375160
1976
06:17
and the National Geographic Society
128
377160
2336
06:19
is helping us to explore these fossil deposits.
129
379520
2231
06:21
This is Riversleigh.
130
381775
1521
06:23
In those fossil rocks are some amazing animals.
131
383320
3056
06:26
We found marsupial lions.
132
386400
1896
06:28
We found carnivorous kangaroos.
133
388320
2576
06:30
It's not what you usually think about as a kangaroo,
134
390920
2456
06:33
but these are meat-eating kangaroos.
135
393400
1736
06:35
We found the biggest bird in the world,
136
395160
1896
06:37
bigger than that thing that was in Madagascar,
137
397080
2143
06:39
and it too was a flesh eater.
138
399247
1489
06:40
It was a giant, weird duck.
139
400760
2256
06:43
And crocodiles were not behaving at that time either.
140
403040
2896
06:45
You think of crocodiles as doing their ugly thing,
141
405960
2376
06:48
sitting in a pool of water.
142
408360
1416
06:49
These crocodiles were actually out on the land
143
409800
2536
06:52
and they were even climbing trees and jumping on prey on the ground.
144
412360
5216
06:57
We had, in Australia, drop crocs. They really do exist.
145
417600
4151
07:01
(Laughter)
146
421775
1099
07:02
But what they were dropping on was not only other weird animals
147
422898
3018
07:05
but also thylacines.
148
425940
1276
07:07
There were five different kinds of thylacines in those ancient forests,
149
427240
3936
07:11
and they ranged from great big ones to middle-sized ones
150
431200
4456
07:15
to one that was about the size of a chihuahua.
151
435680
3736
07:19
Paris Hilton would have been able
152
439440
1616
07:21
to carry one of these things around in a little handbag,
153
441080
2656
07:23
until a drop croc landed on her.
154
443760
1776
07:25
At any rate, it was a fascinating place,
155
445560
1936
07:27
but unfortunately, Australia didn't stay this way.
156
447520
2776
07:30
Climate change has affected the world for a long period of time,
157
450320
3496
07:33
and gradually, the forests disappeared, the country began to dry out,
158
453840
4416
07:38
and the number of kinds of thylacines began to decline,
159
458280
2616
07:40
until by five million years ago,
160
460920
1576
07:42
only one left.
161
462520
1176
07:43
By 10,000 years ago, they had disappeared from New Guinea,
162
463720
3536
07:47
and unfortunately, by 4,000 years ago, somebodies, we don't know who this was,
163
467280
6856
07:54
introduced dingoes -- this is a very archaic kind of a dog --
164
474160
3736
07:57
into Australia.
165
477920
1216
07:59
And as you can see,
166
479160
1216
08:00
dingoes are very similar in their body form to thylacines.
167
480400
2816
08:03
That similarity meant they probably competed.
168
483240
2936
08:06
They were eating the same kinds of foods.
169
486200
1976
08:08
It's even possible that aborigines were keeping some of these dingoes as pets,
170
488200
4616
08:12
and therefore they may have had an advantage in the battle for survival.
171
492840
3436
08:16
All we know is, soon after the dingoes were brought in,
172
496300
2616
08:18
thylacines were extinct in the Australian mainland,
173
498940
2416
08:21
and after that they only survived in Tasmania.
174
501380
2478
08:25
Then, unfortunately,
175
505480
1216
08:26
the next sad part of the thylacine story is that Europeans arrived in 1788,
176
506720
4536
08:31
and they brought with them the things they valued,
177
511280
2776
08:34
and that included sheep.
178
514080
1680
08:36
They took one look at the thylacine in Tasmania,
179
516360
2536
08:38
and they thought, hang on, this is not going to work.
180
518920
3096
08:42
That guy is going to eat all our sheep.
181
522040
2247
08:44
That was not what happened, actually.
182
524938
2238
08:47
Wild dogs did eat a few of the sheep, but the thylacine got a bad rap.
183
527200
3575
08:50
But immediately, the government said, that's it, let's get rid of them,
184
530799
3976
08:54
and they paid people to slaughter every one that they saw.
185
534799
3253
08:58
By the early 1930s,
186
538600
2296
09:00
3,000 to 4,000 thylacines had been murdered.
187
540920
3816
09:04
It was a disaster, and they were about to hit the wall.
188
544760
3365
09:09
Have a look at this bit of film footage.
189
549080
2456
09:11
It makes me very sad because, while it's a fascinating animal,
190
551560
3736
09:15
and it's amazing to think that we had the technology to film it
191
555320
5056
09:20
before it actually plunged off that cliff of extinction,
192
560400
4056
09:24
we didn't, unfortunately, at this same time,
193
564480
2616
09:27
have a molecule of concern about the welfare for this species.
194
567120
4056
09:31
These are photos of the last surviving thylacine, Benjamin,
195
571200
3376
09:34
who was in the Beaumaris Zoo in Hobart.
196
574600
2299
09:37
To add insult to injury,
197
577680
1616
09:39
having swept this species nearly off the table,
198
579320
3696
09:43
this animal, when it died of neglect --
199
583040
2496
09:45
The keepers didn't let it into the hutch on a cold night in Hobart.
200
585560
3981
09:50
It died of exposure, and in the morning, when they found the body of Benjamin,
201
590080
3856
09:53
they still cared so little for this animal that they threw the body in the dump.
202
593960
4978
10:00
Does it have to stay this way?
203
600600
1920
10:03
In 1990, I was in the Australian Museum.
204
603720
2376
10:06
I was fascinated by thylacines.
205
606120
1736
10:07
I've always been obsessed with these animals.
206
607880
2096
10:10
And I was studying skulls,
207
610000
1256
10:11
trying to figure out their relationships to other sorts of animals,
208
611280
3256
10:14
and I saw this jar,
209
614560
1976
10:16
and here, in the jar, was a little girl thylacine pup,
210
616560
4536
10:21
perhaps six months old.
211
621120
1696
10:22
The guy who had found it and killed the mother
212
622840
2336
10:25
had pickled the pup, and they pickled it in alcohol.
213
625200
3136
10:28
I'm a paleontologist, but I still knew alcohol was a DNA preservative.
214
628360
3616
10:32
But this was 1990, and I asked my geneticist friends,
215
632000
4336
10:36
couldn't we think about going into this pup
216
636360
2416
10:38
and extracting DNA, if it's there,
217
638800
2976
10:41
and then somewhere down the line in the future,
218
641800
2216
10:44
we'll use this DNA to bring the thylacine back?
219
644040
2216
10:46
The geneticists laughed. But this was six years before Dolly.
220
646280
3755
10:50
Cloning was science fiction.
221
650791
1747
10:52
It had not happened.
222
652562
1234
10:53
But then suddenly cloning did happen.
223
653820
2396
10:56
And I thought, when I became director of the Australian Museum,
224
656240
3136
10:59
I'm going to give this a go.
225
659400
1336
11:00
I put a team together.
226
660760
1456
11:02
We went into that pup to see what was in it,
227
662240
2856
11:05
and we did find thylacine DNA.
228
665120
2176
11:07
It was a eureka moment. We were very excited.
229
667320
2176
11:09
Unfortunately, we also found a lot of human DNA.
230
669520
3696
11:13
Every old curator who'd been in that museum
231
673240
2976
11:16
had seen this wonderful specimen,
232
676240
1856
11:18
put their hand in the jar, pulled it out and thought,
233
678120
2496
11:20
"Wow, look at that," plop, dropped it back in the jar,
234
680640
2536
11:23
contaminating this specimen.
235
683200
1576
11:24
And that was a worry.
236
684800
1296
11:26
If the goal here was to get the DNA out
237
686120
2216
11:28
and use the DNA down the track to try to bring a thylacine back,
238
688360
3936
11:32
what we didn't want happening
239
692320
1416
11:33
when the information was shoved into the machine
240
693760
2256
11:36
and the wheel turned around and the lights flashed,
241
696040
2416
11:38
was to have a wizened old horrible curator pop out the other end of the machine.
242
698480
3976
11:42
It would've kept the curator very happy, but it wasn't going to keep us happy.
243
702480
3696
11:46
So we went back to these specimens and we started digging around,
244
706200
3056
11:49
and particularly, we looked into the teeth of skulls,
245
709280
3136
11:52
hard parts where humans had not been able to get their fingers,
246
712440
3056
11:55
and we found much better quality DNA.
247
715520
1944
11:58
We found nuclear mitochondrial genes.
248
718000
2176
12:00
It's there. So we got it.
249
720200
1496
12:01
OK. What could we do with this stuff?
250
721720
2456
12:04
Well, George Church, in his book, "Regenesis,"
251
724200
2196
12:06
has mentioned many of the techniques that are rapidly advancing
252
726420
3036
12:09
to work with fragmented DNA.
253
729480
1614
12:11
We would hope that we'll be able to get that DNA back into a viable form,
254
731520
4616
12:16
and then, much like we've done with the Lazarus Project,
255
736160
2656
12:18
get that stuff into an egg of a host species.
256
738840
3056
12:21
It has to be a different species. What could it be?
257
741920
2416
12:24
Why couldn't it be a Tasmanian devil?
258
744360
1776
12:26
They're related, distantly, to thylacines.
259
746160
2066
12:28
And then the Tasmanian devil is going to pop a thylacine out the south end.
260
748760
3690
12:33
Critics of this project say, hang on.
261
753164
3012
12:36
Thylacine, Tasmanian devil? That's going to hurt.
262
756200
3607
12:40
No, it's not. These are marsupials.
263
760320
2856
12:43
They give birth to babies that are the size of a jelly bean.
264
763200
2856
12:46
That Tasmanian devil's not even going to know it gave birth.
265
766080
3376
12:49
It is, shortly, going to think
266
769480
1456
12:50
it's got the ugliest Tasmanian devil baby in the world,
267
770960
3096
12:54
so maybe it'll need some help to keep it going.
268
774080
2913
12:58
Andrew Pask and his colleagues have demonstrated
269
778440
2256
13:00
this might not be a waste of time.
270
780720
1856
13:02
And it's sort of in the future, we haven't got there yet,
271
782600
2696
13:05
but it's the kind of thing we want to think about.
272
785320
2376
13:07
They took some of this same pickled thylacine DNA
273
787720
2536
13:10
and they spliced it into a mouse genome,
274
790280
3296
13:13
but they put a tag on it
275
793600
1496
13:15
so that anything that this thylacine DNA produced
276
795120
3976
13:19
would appear blue-green in the mouse baby.
277
799120
2856
13:22
In other words, if thylacine tissues were being produced by the thylacine DNA,
278
802000
4136
13:26
it would be able to be recognized.
279
806160
1896
13:28
When the baby popped up, it was filled with blue-green tissues.
280
808080
4016
13:32
And that tells us if we can get that genome back together,
281
812120
2776
13:34
get it into a live cell,
282
814920
1456
13:36
it's going to produce thylacine stuff.
283
816400
2494
13:39
Is this a risk?
284
819440
1536
13:41
You've taken the bits of one animal
285
821000
1936
13:42
and you've mixed them into the cell of a different kind of an animal.
286
822960
3247
13:46
Are we going to get a Frankenstein? Some kind of weird hybrid chimera?
287
826231
4105
13:50
And the answer is no.
288
830360
1256
13:51
If the only nuclear DNA that goes into this hybrid cell is thylacine DNA,
289
831640
4736
13:56
that's the only thing that can pop out the other end of the devil.
290
836400
3170
14:00
OK, if we can do this, could we put it back?
291
840520
3496
14:04
This is a key question for everybody.
292
844040
1776
14:05
Does it have to stay in a laboratory, or could we put it back where it belongs?
293
845840
3736
14:09
Could we put it back in the throne of the king of beasts in Tasmania,
294
849600
3376
14:13
restore that ecosystem?
295
853000
1496
14:14
Or has Tasmania changed so much that that's no longer possible?
296
854520
3909
14:19
I've been to Tasmania.
297
859000
1776
14:20
I've been to many of the areas where the thylacines were common.
298
860800
3016
14:23
I've even spoken to people, like Peter Carter here,
299
863840
2856
14:26
who when I spoke to him, was 90 years old,
300
866720
2256
14:29
but in 1926, this man and his father and his brother
301
869000
3856
14:32
caught thylacines.
302
872880
1376
14:34
They trapped them.
303
874280
1336
14:35
And when I spoke to this man, I was looking in his eyes and thinking,
304
875640
4296
14:39
"Behind those eyes is a brain that has memories of what thylacines feel like,
305
879960
6176
14:46
what they smelled like, what they sounded like."
306
886160
2456
14:48
He led them around on a rope.
307
888640
1536
14:50
He has personal experiences
308
890200
2056
14:52
that I would give my left leg to have in my head.
309
892280
3219
14:56
We'd all love to have this sort of thing happen.
310
896000
2296
14:58
Anyway, I asked Peter, by any chance,
311
898320
2256
15:00
could he take us back to where he caught those thylacines.
312
900600
2736
15:03
My interest was in whether the environment had changed.
313
903360
2616
15:06
He thought hard. It was nearly 80 years before this that he'd been at this hut.
314
906000
3776
15:09
At any rate, he led us down this bush track,
315
909800
2256
15:12
and there, right where he remembered,
316
912080
1976
15:14
was the hut,
317
914080
1256
15:15
and tears came into his eyes.
318
915360
2456
15:17
He looked at the hut. We went inside.
319
917840
1816
15:19
There were the wooden boards on the sides of the hut
320
919680
2456
15:22
where he and his father and his brother had slept at night.
321
922160
2776
15:24
And he told me, as it all was flooding back in memories.
322
924960
2656
15:27
He said, "I remember the thylacines going around the hut
323
927640
2656
15:30
wondering what was inside,"
324
930320
1336
15:31
and he said they made sounds like "Yip! Yip! Yip!"
325
931680
3496
15:35
All of these are parts of his life and what he remembers.
326
935200
3216
15:38
And the key question for me was to ask Peter, has it changed?
327
938440
3416
15:41
And he said no.
328
941880
1216
15:43
The southern beech forests surrounded his hut
329
943120
2136
15:45
just like it was when he was there in 1926.
330
945280
2336
15:47
The grasslands were sweeping away.
331
947640
1976
15:49
That's classic thylacine habitat.
332
949640
1976
15:51
And the animals in those areas were the same that were there
333
951640
2856
15:54
when the thylacine was around.
334
954520
1456
15:56
So could we put it back? Yes.
335
956000
1520
15:58
Is that all we would do? And this is an interesting question.
336
958640
3616
16:02
Sometimes you might be able to put it back,
337
962280
2256
16:04
but is that the safest way to make sure it never goes extinct again?
338
964560
3216
16:07
And I don't think so.
339
967800
1536
16:09
I think gradually, as we see species all around the world,
340
969360
3296
16:12
it's kind of a mantra that wildlife is increasingly not safe in the wild.
341
972680
3776
16:16
We'd love to think it is, but we know it isn't.
342
976480
2191
16:18
We need other parallel strategies coming online.
343
978695
2401
16:21
And this one interests me.
344
981120
1496
16:22
Some of the thylacines that were being turned in to zoos,
345
982640
2722
16:25
sanctuaries, even at the museums,
346
985386
1750
16:27
had collar marks on the neck.
347
987160
1845
16:29
They were being kept as pets,
348
989520
1896
16:31
and we know a lot of bush tales and memories
349
991440
2976
16:34
of people who had them as pets,
350
994440
1536
16:36
and they say they were wonderful, friendly.
351
996000
2176
16:38
This particular one
352
998200
1216
16:39
came in out of the forest to lick this boy
353
999440
2976
16:42
and curled up around the fireplace to go to sleep.
354
1002440
2610
16:45
A wild animal.
355
1005074
1382
16:46
And I'd like to ask the question. We need to think about this.
356
1006480
4296
16:50
If it had not been illegal to keep these thylacines as pets then,
357
1010800
5456
16:56
would the thylacine be extinct now?
358
1016280
2176
16:58
And I'm positive it wouldn't.
359
1018480
1736
17:00
We need to think about this in today's world.
360
1020240
2492
17:03
Could it be that getting animals close to us so that we value them,
361
1023240
4536
17:07
maybe they won't go extinct?
362
1027800
1376
17:09
And this is such a critical issue for us
363
1029200
2536
17:11
because if we don't do that,
364
1031760
1336
17:13
we're going to watch more of these animals plunge off the precipice.
365
1033120
4136
17:17
As far as I'm concerned,
366
1037280
1216
17:18
this is why we're trying to do these kinds of de-extinction projects.
367
1038520
4136
17:22
We are trying to restore that balance of nature
368
1042680
3056
17:25
that we have upset.
369
1045760
1565
17:27
Thank you.
370
1047793
1183
17:29
(Applause)
371
1049000
2720
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7