Resurrection Biology: How to Bring Animals Back From Extinction

In May 2013, Russian researchers found a perfectly preserved Woolly Mammoth carcass frozen in the ice on an island off Siberia. As if it were pulled straight out of a meat locker, the animal’s body still had fresh red muscle tissue, and the real prize, liquid blood. The female mammoth had been laying there like Snow White in her glass coffin for four thousand to ten thousand years before the Russians came excavating, bringing with them the hope that she might live again to feel the sun on her shaggy brow. Scientists have cracked much of the mammoth’s genetic code from preserved hair, but the potential to clone the animals isn’t possible without living cells and this mammoth is currently being examined for just that. But even if the scientists don’t find any viable cells in their specimen, there’s more than one way to skin a mammoth and one way or another, humans now have the technology to bring animals back from extinction. sort of. *Theme Plays* The concept of bringing extinct species back from the void has titillated scientists long before those crafty velociraptors jiggled doorknobs in Jurassic Park. It’s called de-extinction or, if you’re feeling more poetic, resurrection biology and it’s a real hot topic nowadays. So let’s cut to the chase: will you ever get to feed a baby Stegosaurus? No. Sorry. While Jurassic Park got some things right, there are some major biological limitations to resurrecting extinct species. DNA naturally degrades over time, and you need some intact genetic material to reconstruct a genome. Scientists recently determined that DNA can remain intact for no more than about 6.8 million years. Not bad, but dinosaurs haven’t been around for about 65 million years so, for better or for worse, you will never have to escape a velociraptor. Instead, the only vanished species that we can attempt to revive are the ones that died relatively recently, within the past few tens of thousands of years. Which is really kind of fitting considering that’s the very same timeframe in which humans got serious about hunting and expanding and general domination. Many proponents of de-extinction think that, if these species were driven to extinction at the hands of humans, then it’s our moral obligation to restore them if we can. So, how exactly, would you resurrect a vanished species? Well, there are currently three possible methods: cloning, genetic reconstruction, and back breeding. In 2003, French and Spanish scientists did bring back a dead species to life for, like, ten minutes. The Pyrenean Ibex, a type of wild large goat with majestic horns, also known as the Bucardo, once climbed among the mountains between Spain and France until it was hunted to extinction by the late 1990’s. Scientists used frozen cells collected from the last known Bucardo, a female named Celia, to create a new embryo through the nuclear transfer method of cloning, which was perfected by the people who gave us Dolly the sheep, the first mammal cloned from an adult cell back in 1996. Researchers injected nuclei from the Bucardo cells into goat eggs that had been stripped of their own DNA and then implanted the eggs into living mama goats. In nearly 60 attempts, only 7 lady goats got knocked up, and only one carried her clone baby to term. Sadly, the newborn came out with deformed lungs and didn’t survive. Still, in terms of bringing an extinct animal back to life, those scientists had way better genetic material to work with than the average de-extinction lab. But, say you want to clone something that isn’t newly extinct, like the Baccardo. Say, a Woolly Mammoth. Researchers have already found a decent payload of mammoth parts: bone marrow, hair, skin, muscle tissue, fat, and that blood I mentioned. The ideal cloning scenario starts with finding an intact frozen cell. The last Mammoth went extinct nearly 4000 years ago and permafrost does a decent job of preserving genetic material compared to, say, the tropical island where dodos last nested. So, it’ll be a lot easier to scrounge up material to make a mammoth than a dodo. But most scientists doubt that an animal cell could survive several millennia under the Siberian Tundra Still, for the sake of exercising the imagination, say they did find a genetically viable mammoth cell, you can remove the nucleus of this cell and transfer it into a hollowed-out elephant egg, since elephants are the mammoths closest living relatives. But then there’s another problem. Elephants only ovulate every five years, and to get the eggs you have to navigate a reproductive tract that’s three meters long! This makes egg extraction from elephants, uh, hard, to say the least. And it could require hundreds of eggs to create one viable offspring. So, again, we have to assume that we overcome that hurdle. So, if the mammoth DNA is healthy enough it could take command of an elephant egg. With the help of a little chemical or electrical boost, the cell would start dividing. From there, you just got to put on a little Barry White and implant the egg into a surrogate elephant’s womb and, after nearly two years of gestation, you’ve got a baby mammoth. Maybe. But, in the absence of the viable cells or nuclei required for cloning, scientists have another path to bring back host species: genetically reconstructing a genome. This new DNA technology is cutting-edge, and requires only fragments of broken genetic material from hair, horn, fur, or feather – things that you can often just find from museum specimens. You basically just sequence and line up the DNA of extinct species, say, a passenger pigeon and compare it to the DNA of closely-related existing species, like a common pigeon, a rock dove. After comparing the two, you essentially start cutting and pasting, substituting chunks of passenger pigeon DNA into the cells of the common pigeon’s. The resulting hybrid stem cells could be coaxed into egg and sperm cells, and then used in cloning. Eventually, you’d end up with a living bird with enough passenger pigeon DNA to pretty much be a passenger pigeon. Another lower-tech and very slow method to restore extinct species is to back breed it. Back breeding is kind of like reverse engineering evolution, much in the way that dog breeders work out particular traits, like body shape or coat color, back breeders look to the past to bring out old ancestral genes in an animal. Take something like the Aurochs, an ancient, wild, cow-like beast formerly found in Europe and Asia. Researchers know some of the Aurochs genes are still swimming around in certain cattle strains, kind of like how humans have 1 – 4 percent Neanderthal DNA in their blood. The European TaurOs project has identified some of these Aurochs genes in existing cattle breeds and is selectively breeding them to bring out those ancient traits. Over the course of multiple generations, they hope to produce a breed that would be a close match to the Aurochs and, ultimately, Introduce it into the wild. In theory, like, crazy insane theory, you could even bring back Neanderthals this same way, although, since it takes between one and two decades for a single human generation to reach sexual maturity, this much breeding would take a long, long time. And also, as previously mentioned, it would be totally, like, immoral and wrong and crazy, which brings us to the potential problems with resurrection biology. Like, for one, would these test tube clone babies be a bunch of inbred hybrid weirdos? Critics of de-extinction worry that resurrected species would suffer from poor genetic variation. Like, if scientists created 20 identical Great Auks from a single egg, there wouldn’t be enough genetic diversity to usher in a viable new population. After all, bringing to life one individual does not constitute the restoration of a species. And, even if you do manage to create a gaggle of Great Auks, where would you put them if there’s no habitat left for them? It comes down to the question of where and how they will live. Most species we’re even capable of resurrecting were initially driven to extinction at the hands of humans. But, if current policy won’t allow for a living species – bison, for example – to freely roam it’s original Great Plains habitat, or if African farmers worry about rampaging elephants, who’s realistically going to welcome Woolly Mammoths into their backyard? And who’s going to teach those first mammoths how to be mammoths? What will they eat? How will they act? How will they learn? Do you think that they’re going to be elephants putting on shaggy coats and moving to Siberia? The whole concept is a big Pandora’s Box. And critics also worry that domino effects may spring from reintroducing extinct species to landscapes that they’ve been away from for too long. Would passenger pigeons really be more like an invasive species that might outcompete existing birds? And if their numbers approach the sky blackening proportions that they used to, would New Yorkers be cool with their fancy shoes getting soiled by slogging through so much bird poop? These are all things we need to think about before we throw a lot of time and money into this kind of research. But, on the pro side, fans of de-extinction point out that resurrection biology has multiple awesome applications. This kind of technology could help preserve and bring back from the brink of extinction vulnerable living species, for instance, which, in itself, could make it worth developing. And it offers a lot of learning opportunities to be found in dead species. You know, we’ve already revived at least one life form for educational purposes, the notorious 1918 Spanish influenza virus that slaughtered perhaps 50 million people back in the day. In 2005, researchers from the Centers for Disease Control and Prevention cloned the killer in order to study it and we’ve since learned a lot about how that flu evolves, spreads, and so efficiently kills. This is potentially vital information that could help us prevent future epidemics. Another argument for de-extinction has to do with filling ecological niches, when a species is eliminated from its natural environment, It leaves a void that could have far-reaching effects. Some de-extinction proponents fantasize about correcting ecosystems like the Arctic by reintroducing mammoths, who once helped maintain the permafrost layer by knocking down trees and allowing grasses to flourish. We’re just starting to realize how important it is to preserve permafrost since its melting releases an incredible amount of methane into the atmosphere The thought is mammoths on the landscape might help with that kind of natural regulation. And, finally, It’s just cool! Just admit it, the thought of watching a giant ground sloth grazing in the real world, in real life, with your eyes. That’s exciting! So, once again, our technological capabilities have shot beyond our capacity to fully understand their implications. However you personally feel about bringing extinct species back to life and all that comes with it, know that it is no longer a question of can we, but rather a matter of should we. Thanks for watching this episode of SciShow. If you have any questions or comments or ideas for us you can leave them on Facebook or Twitter or down in the comments below and if, you want to keep getting smarter with us here at SciShow, you can go to and subscribe. *Theme Plays*

100 thoughts on “Resurrection Biology: How to Bring Animals Back From Extinction

  1. Idk if we should bring them back. If the off chance of their offsprings evolving and becoming intelligent enough to shame us for hunting their ancestors to extinction then bringing them back. This is gonna be something for the Ethics committee..

  2. …Okay, this video is making me hyper-aware of the fact that Hank has ENORMOUS HANDS WHAT THE HELL.

    No shame, bruv, but jeez, man.

  3. In California, the Joshua Tree forest have been declining since the extinction of the giant ground sloth. The sloth would eat the flowers and seeds to distribute them across the desert ensuring the Joshua Tree always ended up in a climate they could grow. The climate Joshua Tree needs is pretty specific across temperature and rain fall requirements, like a micro climate in the desert.

  4. Oh, yeah, , that’s how it always starts,,, then later there’s running, and screaming,,, “

  5. I like the idea of an African elephant searching job boards and stumbling across that training opportunity. The other elephant hold tryouts and he passes. He has to talk to his elephant wife and explain why it's so important to go. His wife then presents him with a coat and wishes him off.

  6. I have full faith in science getting this done in time to save us some high risk key stine species

  7. Maori eagle maybe? I'd like to see babies being carried off by giant birds again.

  8. OK if we are going to start resurrecting extinct species they better put ground sloths high on the priority list

  9. bring back a virus to prevent viruses from killing humas…… Biology is awesome!

  10. I'm surprised they didn't mention the option of turning off and on dormant genes in modern animals to revert traits long lost to them. Like the researchers who successfully made chickens born with teeth. Flip enough switchesand suddenly you have a less and less avian dinosaur.

  11. I think all of this will become reality if we became united and started reversing the damage we caused to the environment.

  12. Weird that some people think it's our moral imperative to bring species back from extinction. To me, not bringing a species back from extinction seems less wrong than impregnating a bunch of animals against their will to produce deformed animal babies that suffer and then die.

    I'm not even an animal rights activist normally. I eat meat and wear animal products (down feathers) and I don't see a problem with that. The logic of a "moral imperative" to bring species back from extinction just seems inconsistent to me.

    The science is absolutely worth exploring, though. Not because of some "moral imperative", but just because it could be good for the overall health of the ecosystem that we depend on.

  13. I'm usually a proponent of scientific studies etc., however, "resurrection biology"?! If you think of it from a different mindset, it could be seen as necromancy… Creepy, can't imagine what someone that lived a century ago hearing that in 2013 we can de-extinct species!

  14. Actual human societies are being driven to extinction by industrial agriculture, logging, and mining. But sure, let's put our scarce resources to work cloning mammoths 🙄

  15. An extant species I'd like to see preserved is the honey bee.

    First, I think it won't suffer so much from back breeding because they are clones for the most part anyway, like most all bee species.

    They are still around but are subject to hive collapse. I'm not so worried about flower and tree pollination (though that's important; though other bees and mosquitoes are pollinators, too, who could expand to fill that niche).

    What I want to see happen is the re-population of the inge species of bee that gives us honey!

    It would also be nice to see wild flowers and sorrel and other ground covers to return to our lawns.

  16. Has anyone considered we may have killed off mammoth because they killed us. Elephant brain (s) show a (smart) mammal. A mammoth could possibly have been an invasive creature for early hominids.

  17. Update: They’ve just created a mammoth embryo in an artificial womb and it will hopefully be born in 2 years.

  18. Wait wait wait. Then we should be able to bring back past extinct homonids right?

  19. And everything said for the first 22 seconds of this video sounds like the beginning of some ice age version of Jurassic Park….. Cue the scientists doing something really really stupid for profit

  20. Funny how this video popped up. I'm currently playing a game of Rimworld which have resurrected megasloths in it.

  21. Funny how we try to clone a mammoth when we can't even save the current elephants.

  22. Concerning the problem of having enough genetic variation to prevent the effects of inbreeding, it seems to me that if we can manipulate DNA in such a way as to revive extinct species, we ought to be able to program in some genetic variation to avoid those problems until the population gets big enough that it doesn't need us to do that anymore.

  23. Yes we should, so that we can hunt them back to extinction again and teach those other animals who is numero uno in the playground

  24. Funny how selectively breeding humans is immoral and wrong and crazy, but when it comes to other species it's somehow okay. And by funny I mean sad.

  25. If we plan on doing something like this we should focus on the most recently extinct then work our way back. We should also be careful with it because the further back we go the more likely an animal could disrupt todays ecosystem. What I mean by this is depending on how long an animal was extinct, the more likely is would act as an invasive species, even if we put them back in their original habitat and that would only make other species that took over the area going extinct themselves.
    Basically, I'm saying that we should be careful.

  26. Who cares about New Yorkers' shoes? The demi-demented denizens of the 'fly-out-of-states' are way too out of touch with nature. Having to do a little barnyard hopscotch would be good for them.

  27. So geneticists have a couple neat tricks and no real way to show them off.

  28. Who cares if some humans may find deextinction inconvenient? Let them be inconvenienced; Man was responsible for so much damage to the environment.

  29. Those Mammoths will have instinct as they always have. Now that they've discovered genetic memory inherited straight from DNA, one can assume even a resurrected species will have it, given… we're using their DNA/RNA

  30. The circle of permafrost: permafrost melts, releases methane methane boosts global warming and then restart

  31. Be tread REAL lightly when he said humans take between ONE and two decades to hit maturity

  32. If i could go back in time id go back gather every animal or plant cell thats ever been on earth and bring them back to make my extinction park

  33. Couldn't we combine back breeding and construction of a genome to get closer and faster to the desired result?

  34. Humans have done enough. They should not resurrect extinct species regardless of the cause of their extinction. Until humans can learn to be better stewards of nature and their environment, they need to leave as small of an influential footprint as possible.

  35. If we cannot responsibly manage our impact on the species that currently exist, how is it a good idea to bring any extinct species back?

  36. A hunter aims his gun at a mammoth grazing… a twig snaps to his left… in the moment before he is trampled to death he mutters… “Clever Girl”

  37. you prove only that there are over five million dickheads on the planet (your subscribers)

  38. I would love to resurrect a Megalainia lizard it would probably be the closest thing we would get to a jurassic park dinosaur

  39. China and India will do it if they can. They don't have their hands tie with religious people that don't understand that not everything is bad a out the science, some things are 100% beneficial to humans and if we don't do it somebody else will ende up doing it…

  40. So you're saying that I'll never be able to saddle and ride a deinonychus or a hell pig, but a terror bird is still (hypothetically) possible.

  41. I'm surprised you didn't mention the quagga. A group is back breeding them from zebras. Because a quagga was a subspecies of zebra. A lot of them really do look like the quagga.

  42. What would be the point of back-breeding to make neanderthals? There's already enough hairy, dumb people walking around.

  43. every time i see a picture of a dodo i get mad why could humans not just leave the shity little birds alone the things look hilarious and humans just wiped them out would love to be able to see dodos first person today

  44. I have an idea, let's turn on some genes from humans so I don't have to talk to every idiot I see, like a gene to make some humans more intelligent or less gullible..

  45. Why all people love living dino
    We have dino large dino not t rex not velosoraptor we have ostrich and chicken

  46. “Ah yeah. Ooh ahh. That’s how it always starts. Then later there’s the running and the screaming.”

  47. 7:43 long shot you will see this but here goes; what about genetic memory? Like how do other animals know how to behave if they are orphaned? How do snakes know how to strike if born and never shown? Surely instinct must be saved within the DNA or something?

  48. Everyone screeching about wanting a wooly mammoth, can y’all take a minute to think of the Elephant in this scenario? They’re very intelligent creatures, and pregnancy is hard. Imagine 2 years of it. And then you have her going through all of that for what? So we can keep a wooly mammoth in a zoo for us to gawk at? I find this whole resurrection biology when it comes to animals to be barbaric. Why not bring back certain plants?

  49. Blaming the mass extinction of mega fauna following the last ice age on human hunting is ridiculously biased and simple thinking… climate change is the obvious cause

  50. Wait a moment, chicken => delicious
    chickens are closely related to dinosaurs.
    dinosaurs are probably delicious.

  51. We have tech that inches onto resurrecting and breeding animals which are no logger there; including the tech of synthetic womb. There is also robotics which does its stuff, including more realistic fake animals. I believe these will come together to things like teaching mammoths how to mammoth, and to exclude surrogate animal mothers.

  52. People are gullible idiots easily distracted by something spectacular; and even when scientists aren't much like that, people who would give them money most often are, so they have to engage with spectacular at the expense of more important and more useful (I mean stuff which doesn't look much, but improves our understanding faster or otherwise better).

    I mean, mammoths? They surely look fantastic, but less impressive beasts are definitely easier to manage and less expensive to do something with. I bet some sort of ancient wolf, while not being fancy, would make a better candidate to develop the concept. If not a rat. Or make it something potentially useful, but boring in other regards, like a plant. Or even soil bacteria.

  53. Hair, horn, fur or feather sounds like things a witch would list whilst stirring her cauldron

  54. I am disappointed in the comment section. I didn't see any references to the 6 million dollar man. Smh. You know, the "We have the technology" line?

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