WEBVTT 00:00:00.868 --> 00:00:02.654 When I was a young boy, 00:00:02.654 --> 00:00:05.262 I used to gaze through the microscope of my father 00:00:05.262 --> 00:00:08.620 at the insects in amber that he kept in the house. 00:00:08.620 --> 00:00:11.177 And they were remarkably well preserved, 00:00:11.177 --> 00:00:13.422 morphologically just phenomenal. 00:00:13.422 --> 00:00:15.616 And we used to imagine that someday, 00:00:15.616 --> 00:00:17.225 they would actually come to life 00:00:17.225 --> 00:00:19.222 and they would crawl out of the resin, 00:00:19.222 --> 00:00:21.966 and, if they could, they would fly away. NOTE Paragraph 00:00:21.966 --> 00:00:24.342 If you had asked me 10 years ago whether or not 00:00:24.342 --> 00:00:27.540 we would ever be able to sequence the genome of extinct animals, 00:00:27.540 --> 00:00:30.015 I would have told you, it's unlikely. 00:00:30.015 --> 00:00:31.910 If you had asked whether or not we would actually be able 00:00:31.910 --> 00:00:34.062 to revive an extinct species, 00:00:34.062 --> 00:00:35.721 I would have said, pipe dream. 00:00:35.721 --> 00:00:38.246 But I'm actually standing here today, amazingly, 00:00:38.246 --> 00:00:40.253 to tell you that not only is the sequencing 00:00:40.253 --> 00:00:44.443 of extinct genomes a possibility, actually a modern-day reality, 00:00:44.443 --> 00:00:48.736 but the revival of an extinct species is actually within reach, 00:00:48.736 --> 00:00:50.575 maybe not from the insects in amber -- 00:00:50.575 --> 00:00:52.535 in fact, this mosquito was actually used 00:00:52.535 --> 00:00:54.887 for the inspiration for "Jurassic Park" — 00:00:54.887 --> 00:00:57.447 but from woolly mammoths, the well preserved remains 00:00:57.447 --> 00:00:59.654 of woolly mammoths in the permafrost. NOTE Paragraph 00:00:59.654 --> 00:01:01.727 Woollies are a particularly interesting, 00:01:01.727 --> 00:01:04.273 quintessential image of the Ice Age. 00:01:04.273 --> 00:01:06.098 They were large. They were hairy. 00:01:06.098 --> 00:01:08.082 They had large tusks, and we seem to have 00:01:08.082 --> 00:01:10.982 a very deep connection with them, like we do with elephants. 00:01:10.982 --> 00:01:13.497 Maybe it's because elephants share 00:01:13.497 --> 00:01:15.319 many things in common with us. 00:01:15.319 --> 00:01:18.047 They bury their dead. They educate the next of kin. 00:01:18.047 --> 00:01:21.067 They have social knits that are very close. 00:01:21.067 --> 00:01:23.937 Or maybe it's actually because we're bound by deep time, 00:01:23.937 --> 00:01:27.275 because elephants, like us, share their origins in Africa 00:01:27.275 --> 00:01:29.398 some seven million years ago, 00:01:29.398 --> 00:01:32.192 and as habitats changed and environments changed, 00:01:32.192 --> 00:01:35.802 we actually, like the elephants, migrated out 00:01:35.802 --> 00:01:38.022 into Europe and Asia. NOTE Paragraph 00:01:38.022 --> 00:01:40.725 So the first large mammoth that appears on the scene 00:01:40.725 --> 00:01:44.131 is meridionalis, which was standing four meters tall 00:01:44.131 --> 00:01:47.963 weighing about 10 tons, and was a woodland-adapted species 00:01:47.963 --> 00:01:50.925 and spread from Western Europe clear across Central Asia, 00:01:50.925 --> 00:01:53.175 across the Bering land bridge 00:01:53.175 --> 00:01:55.485 and into parts of North America. 00:01:55.485 --> 00:01:58.173 And then, again, as climate changed as it always does, 00:01:58.173 --> 00:01:59.683 and new habitats opened up, 00:01:59.683 --> 00:02:02.159 we had the arrival of a steppe-adapted species 00:02:02.159 --> 00:02:04.407 called trogontherii in Central Asia 00:02:04.407 --> 00:02:07.157 pushing meridionalis out into Western Europe. 00:02:07.157 --> 00:02:09.552 And the open grassland savannas of North America 00:02:09.552 --> 00:02:11.712 opened up, leading to the Columbian mammoth, 00:02:11.712 --> 00:02:14.252 a large, hairless species in North America. 00:02:14.252 --> 00:02:17.163 And it was really only about 500,000 years later 00:02:17.163 --> 00:02:19.868 that we had the arrival of the woolly, 00:02:19.868 --> 00:02:21.896 the one that we all know and love so much, 00:02:21.896 --> 00:02:25.206 spreading from an East Beringian point of origin 00:02:25.206 --> 00:02:28.092 across Central Asia, again pushing the trogontherii 00:02:28.092 --> 00:02:29.743 out through Central Europe, 00:02:29.743 --> 00:02:31.809 and over hundreds of thousands of years 00:02:31.809 --> 00:02:34.893 migrating back and forth across the Bering land bridge 00:02:34.893 --> 00:02:36.920 during times of glacial peaks 00:02:36.920 --> 00:02:38.716 and coming into direct contact 00:02:38.716 --> 00:02:41.520 with the Columbian relatives living in the south, 00:02:41.520 --> 00:02:44.808 and there they survive over hundreds of thousands of years 00:02:44.808 --> 00:02:46.985 during traumatic climatic shifts. 00:02:46.985 --> 00:02:51.201 So there's a highly plastic animal dealing with great transitions 00:02:51.201 --> 00:02:54.049 in temperature and environment, and doing very, very well. 00:02:54.049 --> 00:02:58.040 And there they survive on the mainland until about 10,000 years ago, 00:02:58.040 --> 00:03:01.193 and actually, surprisingly, on the small islands off of Siberia 00:03:01.193 --> 00:03:03.667 and Alaska until about 3,000 years ago. 00:03:03.667 --> 00:03:05.356 So Egyptians are building pyramids 00:03:05.356 --> 00:03:08.122 and woollies are still living on islands. NOTE Paragraph 00:03:08.122 --> 00:03:09.671 And then they disappear. 00:03:09.671 --> 00:03:11.925 Like 99 percent of all the animals that have once lived, 00:03:11.925 --> 00:03:15.188 they go extinct, likely due to a warming climate 00:03:15.204 --> 00:03:17.286 and fast-encroaching dense forests 00:03:17.286 --> 00:03:18.787 that are migrating north, 00:03:18.787 --> 00:03:21.760 and also, as the late, great Paul Martin once put it, 00:03:21.760 --> 00:03:23.511 probably Pleistocene overkill, 00:03:23.511 --> 00:03:26.084 so the large game hunters that took them down. NOTE Paragraph 00:03:26.084 --> 00:03:28.346 Fortunately, we find millions of their remains 00:03:28.346 --> 00:03:31.023 strewn across the permafrost buried deep 00:03:31.023 --> 00:03:34.148 in Siberia and Alaska, and we can actually go up there 00:03:34.148 --> 00:03:36.058 and actually take them out. 00:03:36.058 --> 00:03:37.582 And the preservation is, again, 00:03:37.582 --> 00:03:40.152 like those insects in [amber], phenomenal. 00:03:40.152 --> 00:03:43.672 So you have teeth, bones with blood 00:03:43.672 --> 00:03:45.712 which look like blood, you have hair, 00:03:45.712 --> 00:03:47.239 and you have intact carcasses or heads 00:03:47.239 --> 00:03:50.182 which still have brains in them. NOTE Paragraph 00:03:50.182 --> 00:03:52.553 So the preservation and the survival of DNA 00:03:52.553 --> 00:03:54.625 depends on many factors, and I have to admit, 00:03:54.625 --> 00:03:56.953 most of which we still don't quite understand, 00:03:56.953 --> 00:03:59.025 but depending upon when an organism dies 00:03:59.025 --> 00:04:03.514 and how quickly he's buried, the depth of that burial, 00:04:03.514 --> 00:04:06.816 the constancy of the temperature of that burial environment, 00:04:06.816 --> 00:04:09.384 will ultimately dictate how long DNA will survive 00:04:09.384 --> 00:04:12.245 over geologically meaningful time frames. 00:04:12.245 --> 00:04:13.889 And it's probably surprising to many of you 00:04:13.889 --> 00:04:17.029 sitting in this room that it's not the time that matters, 00:04:17.029 --> 00:04:18.656 it's not the length of preservation, 00:04:18.656 --> 00:04:22.638 it's the consistency of the temperature of that preservation that matters most. NOTE Paragraph 00:04:22.638 --> 00:04:25.457 So if we were to go deep now within the bones 00:04:25.457 --> 00:04:28.432 and the teeth that actually survived the fossilization process, 00:04:28.432 --> 00:04:31.824 the DNA which was once intact, tightly wrapped 00:04:31.824 --> 00:04:34.192 around histone proteins, is now under attack 00:04:34.192 --> 00:04:37.158 by the bacteria that lived symbiotically with the mammoth 00:04:37.158 --> 00:04:38.968 for years during its lifetime. 00:04:38.968 --> 00:04:42.169 So those bacteria, along with the environmental bacteria, 00:04:42.169 --> 00:04:45.872 free water and oxygen, actually break apart the DNA 00:04:45.872 --> 00:04:48.417 into smaller and smaller and smaller DNA fragments, 00:04:48.417 --> 00:04:50.738 until all you have are fragments that range 00:04:50.738 --> 00:04:53.419 from 10 base pairs to, in the best case scenarios, 00:04:53.419 --> 00:04:55.792 a few hundred base pairs in length. 00:04:55.792 --> 00:04:58.103 So most fossils out there in the fossil record 00:04:58.103 --> 00:05:00.816 are actually completely devoid of all organic signatures. 00:05:00.816 --> 00:05:03.249 But a few of them actually have DNA fragments 00:05:03.249 --> 00:05:05.123 that survive for thousands, 00:05:05.123 --> 00:05:08.872 even a few millions of years in time. 00:05:08.872 --> 00:05:11.060 And using state-of-the-art clean room technology, 00:05:11.060 --> 00:05:13.724 we've devised ways that we can actually pull these DNAs 00:05:13.724 --> 00:05:16.228 away from all the rest of the gunk in there, 00:05:16.228 --> 00:05:18.427 and it's not surprising to any of you sitting in the room 00:05:18.427 --> 00:05:20.548 that if I take a mammoth bone or a tooth 00:05:20.548 --> 00:05:23.547 and I extract its DNA that I'll get mammoth DNA, 00:05:23.547 --> 00:05:27.358 but I'll also get all the bacteria that once lived with the mammoth, 00:05:27.358 --> 00:05:29.605 and, more complicated, I'll get all the DNA 00:05:29.605 --> 00:05:31.789 that survived in that environment with it, 00:05:31.789 --> 00:05:34.963 so the bacteria, the fungi, and so on and so forth. 00:05:34.963 --> 00:05:37.368 Not surprising then again that a mammoth 00:05:37.368 --> 00:05:39.040 preserved in the permafrost will have something 00:05:39.040 --> 00:05:41.908 on the order of 50 percent of its DNA being mammoth, 00:05:41.908 --> 00:05:43.931 whereas something like the Columbian mammoth, 00:05:43.931 --> 00:05:46.548 living in a temperature and buried in a temperate environment 00:05:46.548 --> 00:05:50.365 over its laying-in will only have 3 to 10 percent endogenous. NOTE Paragraph 00:05:50.365 --> 00:05:52.808 But we've come up with very clever ways 00:05:52.808 --> 00:05:55.914 that we can actually discriminate, capture and discriminate, 00:05:55.914 --> 00:05:57.889 the mammoth from the non-mammoth DNA, 00:05:57.889 --> 00:06:00.439 and with the advances in high-throughput sequencing, 00:06:00.439 --> 00:06:03.276 we can actually pull out and bioinformatically 00:06:03.276 --> 00:06:06.245 re-jig all these small mammoth fragments 00:06:06.245 --> 00:06:08.542 and place them onto a backbone 00:06:08.542 --> 00:06:11.101 of an Asian or African elephant chromosome. 00:06:11.101 --> 00:06:13.677 And so by doing that, we can actually get all the little points 00:06:13.677 --> 00:06:16.502 that discriminate between a mammoth and an Asian elephant, 00:06:16.502 --> 00:06:19.541 and what do we know, then, about a mammoth? NOTE Paragraph 00:06:19.541 --> 00:06:22.694 Well, the mammoth genome is almost at full completion, 00:06:22.694 --> 00:06:26.235 and we know that it's actually really big. It's mammoth. 00:06:26.235 --> 00:06:29.420 So a hominid genome is about three billion base pairs, 00:06:29.420 --> 00:06:30.997 but an elephant and mammoth genome 00:06:30.997 --> 00:06:33.653 is about two billion base pairs larger, and most of that 00:06:33.653 --> 00:06:36.277 is composed of small, repetitive DNAs 00:06:36.277 --> 00:06:40.910 that make it very difficult to actually re-jig the entire structure of the genome. NOTE Paragraph 00:06:40.910 --> 00:06:43.271 So having this information allows us to answer 00:06:43.271 --> 00:06:45.406 one of the interesting relationship questions 00:06:45.406 --> 00:06:47.578 between mammoths and their living relatives, 00:06:47.578 --> 00:06:49.622 the African and the Asian elephant, 00:06:49.622 --> 00:06:52.789 all of which shared an ancestor seven million years ago, 00:06:52.789 --> 00:06:54.878 but the genome of the mammoth shows it to share 00:06:54.878 --> 00:06:57.658 a most recent common ancestor with Asian elephants 00:06:57.658 --> 00:06:59.074 about six million years ago, 00:06:59.074 --> 00:07:01.547 so slightly closer to the Asian elephant. NOTE Paragraph 00:07:01.547 --> 00:07:04.271 With advances in ancient DNA technology, 00:07:04.271 --> 00:07:06.224 we can actually now start to begin to sequence 00:07:06.224 --> 00:07:09.535 the genomes of those other extinct mammoth forms that I mentioned, 00:07:09.535 --> 00:07:11.422 and I just wanted to talk about two of them, 00:07:11.422 --> 00:07:13.476 the woolly and the Columbian mammoth, 00:07:13.476 --> 00:07:15.894 both of which were living very close to each other 00:07:15.894 --> 00:07:18.519 during glacial peaks, 00:07:18.519 --> 00:07:20.682 so when the glaciers were massive in North America, 00:07:20.682 --> 00:07:23.277 the woollies were pushed into these subglacial ecotones, 00:07:23.277 --> 00:07:26.488 and came into contact with the relatives living to the south, 00:07:26.488 --> 00:07:28.500 and there they shared refugia, 00:07:28.500 --> 00:07:30.884 and a little bit more than the refugia, it turns out. 00:07:30.884 --> 00:07:33.384 It looks like they were interbreeding. 00:07:33.384 --> 00:07:35.017 And that this is not an uncommon feature 00:07:35.017 --> 00:07:36.655 in Proboscideans, because it turns out 00:07:36.655 --> 00:07:39.568 that large savanna male elephants will outcompete 00:07:39.568 --> 00:07:42.936 the smaller forest elephants for their females. 00:07:42.936 --> 00:07:45.248 So large, hairless Columbians 00:07:45.248 --> 00:07:47.051 outcompeting the smaller male woollies. 00:07:47.051 --> 00:07:49.669 It reminds me a bit of high school, unfortunately. NOTE Paragraph 00:07:49.669 --> 00:07:52.008 (Laughter) NOTE Paragraph 00:07:52.008 --> 00:07:54.702 So this is not trivial, given the idea that we want 00:07:54.702 --> 00:07:56.907 to revive extinct species, because it turns out 00:07:56.907 --> 00:07:58.727 that an African and an Asian elephant 00:07:58.727 --> 00:08:00.822 can actually interbreed and have live young, 00:08:00.822 --> 00:08:02.963 and this has actually occurred by accident in a zoo 00:08:02.963 --> 00:08:06.005 in Chester, U.K., in 1978. 00:08:06.005 --> 00:08:09.151 So that means that we can actually take Asian elephant chromosomes, 00:08:09.151 --> 00:08:11.309 modify them into all those positions we've actually now 00:08:11.309 --> 00:08:13.693 been able to discriminate with the mammoth genome, 00:08:13.693 --> 00:08:16.474 we can put that into an enucleated cell, 00:08:16.474 --> 00:08:18.733 differentiate that into a stem cell, 00:08:18.733 --> 00:08:21.053 subsequently differentiate that maybe into a sperm, 00:08:21.053 --> 00:08:23.677 artificially inseminate an Asian elephant egg, 00:08:23.677 --> 00:08:26.784 and over a long and arduous procedure, 00:08:26.784 --> 00:08:30.293 actually bring back something that looks like this. 00:08:30.293 --> 00:08:31.983 Now, this wouldn't be an exact replica, 00:08:31.983 --> 00:08:34.465 because the short DNA fragments that I told you about 00:08:34.465 --> 00:08:36.946 will prevent us from building the exact structure, 00:08:36.946 --> 00:08:38.482 but it would make something that looked and felt 00:08:38.482 --> 00:08:41.589 very much like a woolly mammoth did. NOTE Paragraph 00:08:41.589 --> 00:08:44.333 Now, when I bring up this with my friends, 00:08:44.333 --> 00:08:46.941 we often talk about, well, where would you put it? 00:08:46.941 --> 00:08:48.629 Where are you going to house a mammoth? 00:08:48.629 --> 00:08:50.669 There's no climates or habitats suitable. 00:08:50.669 --> 00:08:52.009 Well, that's not actually the case. 00:08:52.009 --> 00:08:54.902 It turns out that there are swaths of habitat 00:08:54.902 --> 00:08:57.237 in the north of Siberia and Yukon 00:08:57.237 --> 00:08:58.443 that actually could house a mammoth. 00:08:58.443 --> 00:09:00.688 Remember, this was a highly plastic animal 00:09:00.688 --> 00:09:03.349 that lived over tremendous climate variation. 00:09:03.349 --> 00:09:06.249 So this landscape would be easily able to house it, 00:09:06.249 --> 00:09:09.891 and I have to admit that there isn't a part of the child in me, 00:09:09.891 --> 00:09:11.176 the boy in me, that would love to see 00:09:11.176 --> 00:09:14.022 these majestic creatures walk across the permafrost 00:09:14.022 --> 00:09:16.477 of the north once again, but I do have to admit 00:09:16.477 --> 00:09:18.621 that part of the adult in me sometimes wonders 00:09:18.621 --> 00:09:21.026 whether or not we should. NOTE Paragraph 00:09:21.026 --> 00:09:22.711 Thank you very much. NOTE Paragraph 00:09:22.711 --> 00:09:27.909 (Applause) NOTE Paragraph 00:09:27.909 --> 00:09:29.426 Ryan Phelan: Don't go away. 00:09:29.426 --> 00:09:31.158 You've left us with a question. 00:09:31.158 --> 00:09:34.682 I'm sure everyone is asking this. When you say, "Should we?" 00:09:34.682 --> 00:09:37.291 it feels like you're reticent there, 00:09:37.291 --> 00:09:40.362 and yet you've given us a vision of it being so possible. 00:09:40.362 --> 00:09:41.750 What's your reticence? NOTE Paragraph 00:09:41.750 --> 00:09:42.532 Hendrik Poinar: I don't think it's reticence. 00:09:42.532 --> 00:09:46.699 I think it's just that we have to think very deeply 00:09:46.699 --> 00:09:49.250 about the implications, ramifications of our actions, 00:09:49.250 --> 00:09:51.450 and so as long as we have good, deep discussion 00:09:51.450 --> 00:09:53.466 like we're having now, I think 00:09:53.466 --> 00:09:56.172 we can come to a very good solution as to why to do it. 00:09:56.172 --> 00:09:57.809 But I just want to make sure that we spend time 00:09:57.809 --> 00:09:59.658 thinking about why we're doing it first. NOTE Paragraph 00:09:59.658 --> 00:10:02.439 RP: Perfect. Perfect answer. Thank you very much, Hendrik. NOTE Paragraph 00:10:02.439 --> 00:10:04.903 HP: Thank you. (Applause)