Mary Hurley profile image Mary Hurley

Bringing back dinosaurs, dodos and Elvis: a discussion on de-extinction with science writer Dr Helen Pilcher

A photo collage featuring a T-Rex, Elvis Presley, and a dodo bird.

Conservation is currently buzzing with the idea of de-extinction—a process that has the potential to bring long-dead species back to life. We have the chance to play God, but should we? What are the implications of bringing back something that has already been lost to time? What would these creatures look like? Will there be dinosaurs?

In our interview series De-extinction Dilemma, we tackle some of these difficult questions. 


“Tell me about yourself,” I ask Dr Helen Pilcher, as she and Higgs—her dog that she refers to as a genetically modified wolf—join me over Zoom on a rainy English morning.

"I describe myself as a tea drinking, biscuit nibbling, science and comedy writer," she says, her passion for the world evident. I take a liking to her immediately.

“I’m looking [a bit] weather beaten,” she explains with a laugh. “There's a really rare migrant bird that's landed literally a mile up the road. People were twitching and tweeting about it and I [thought] I've gotta go and see it. He was amazing.”  

Dr Pilcher brings a refreshing approach to a subject that can feel stuffy and out of reach for many of us: science. With a PhD in neuroscience, Dr Pilcher began her research in the early days of genetic modification, exploring the potential for transplanting genetically modifying stem cells into the brains of Alzheimer's patients to alleviate their symptoms.

What sets Dr. Pilcher apart is her knack for humour. In fact, she used to perform stand-up comedy on the side to supplement her income during her university years. And while she still does stand-up on occasion, she more “writes funny” these days, having found her niche in science communication.

Today, we talk about her new book Bring Back the King: The New Science of De-extinction, the complexities of de-extinction and how to separate fantasy from reality when it comes to bringing back a species. 

I love the way you blend science with humour in your writing as it makes a really complex topic so much more accessible. How would you best summarise de-extinction to someone whose only reference point was Jurassic Park?

[Laughs] So de-extinction is the proposed ability of scientists to bring extinct creatures back to life. So it is kind of like Jurassic Park, but it's very, very much a work in progress, is the first thing to say. So nobody has de-extincted anything [successfully]. There are some projects that are ongoing out there trying to de-extinct things like the woolly mammoth, the passenger pigeon, the gastric brooding frog, various other things too, using a whole different variety of methods—but they are a work in progress. So [we are] more or less somewhere along the path to get there. But what we're talking about here is not bringing back dinosaurs, for example. We can't bring back dinosaurs; they died out too long ago. You need a usable source of [a creature's] DNA and we don't have that from dinosaurs, we can find interesting molecules in fossils, but not usable chunks of DNA. So we're not going to be able to bring back a T-Rex, which I'm mildly devastated about because I would love to see one, but there are potentially various other animals that are on the table.

But the big thing to say about [de-extinction] is you're not looking to make an absolute replica of what there was—it would never be identical. So the scientists who are trying to recreate the woolly mammoth, they're trying to make something that is like, I suppose, a modern day proxy of the woolly mammoth. It will never be identical and there are many reasons for that that we can go into but, you know, living things are a product, not just of their DNA and their biology, but the environment that they live in. We're more than just our cells, we're part of the environment [so] with the environment changing, and because of the methods that people have to use for de-extinction, you would end up with something that is very, very similar but not exactly the same. So it's more like engineering a 21st century proxy. So that's basically what de-extinction is. It's about making 21st century facsimiles of animals that have been extinct for some time.

Headshot of Helen Pilcher and the cover of her book 'Bring Back the King: the Science of De-extinction'.
Helen Pilcher is a science and comedy writer, presenter and the author of the book Bring Back the King: the Science of De-extinction.

I really like what you said about being the product of your environment, that's not something I've heard in the de-extinction discussion yet. So I think that adds another interesting element to it. What does de-extinction mean to you and why were you inspired to explore it so deeply?

What does it mean to me? Well I was inspired to explore it because I came across this story of an animal called the bucardo, or the Pyrenean ibex, a mountain goat that used to live in the Pyrenees mountain range between Spain and France. And these were hugely successful animals, they lived there for tens of thousands of years and then they pretty much went extinct because of human hunting pressure. They had these enormous great big curved horns and were really stunning animals, but people liked to kill them and put their heads on their walls. Humans are not great like that. So around the late 90s, the numbers had dwindled significantly. They tried to introduce conservation measures but it was too little too late and there ended up becoming one lone, last female called Celia. The researchers knew that they had to do something to preserve or save this animal, so while she was alive they took some biopsy samples and they froze them away just thinking, well maybe one day we can do something. And then Celia died and the species went extinct. Then in the early 2000s, some scientists from Spain thawed those original cells and used them for cloning. Most people have heard of Dolly the sheep, who was the first mammal to be cloned from an adult cell. The same kind of methods that were used to make Dolly were used on Celia the bucardo's cells and they made a little cloned bucardo. And so [in] July 2003, the first de-extinct animal was born. And this was an absolutely ground changing moment because it was the first time that anything had been brought back from extinction. So for all intents and purposes, the little clone that had been created was genetically identical to the very last living bucardo and Celia was dead at this point. And then, sadly, this little animal, she died just a few minutes after she was born and they think that was due to errors in the cloning process. So the bucardo was not just the first animal to be de-extincted, it was the first animal to go extinct twice. Which is mind-blowing if you think about it.

So I came across this story and it hadn't received a huge amount of attention and it took the scientists quite a long time to publish this story. And that's when I kind of thought, you know, from my background being interested in wildlife and being interested in gene editing and cloning and cell biology, if this is possible, what else is possible? How far could you take this technology? Could we really bring back the bucardo, [successfully]? You know, if they perfected cloning, could we do this? And if you could bring back the bucardo, what else could you bring back? Could you bring back a woolly mammoth? Could you bring back a dinosaur? And then this thought experiment in my brain got even bigger and I thought, well what about extinct humans? Could you bring back a Neanderthal? There's this amazing extinct species of humancalled the Denisovans   which were discovered recently and which we only really know from literally a handful of bones. What about if we were able to bring them back from the DNA inside their bones? Because we know next to nothing about them. What would the ethics of that be? How would it even be possible? And [laughs] then I realized you could buy a sample of Elvis Presley's hair on eBay. If you go on eBay, you can buy all sorts of questionable things including hair and occasionally body parts from people.

Ooh!

Yeah, there was a rumour that Napoleon Bonaparte's penis went up for sale on eBay. [Laughs] It is apparently preserved somewhere, I don't know anything about it.

[Laughs]

Yeah, so I kind of had this thought experiment about whether you could bring back Elvis Presley from a sample of his hair on eBay. And so I went to the trouble of buying some hair on eBay and went down this thought experiment with some of the world's leading geneticists to see if it could be possible. And the answer is that technologically we are far more able to de-extinct Elvis Presley than we are a woolly mammoth because we know so much more about human biology than we do about mammoth biology or elephant biology. But, you know, nobody is suggesting that we should clone humans, it's a thought experiment, it would be a terrible idea for lots of reasons. But the other reason I wanted to talk about it in the book is that it gives you a chance to talk about what we've just touched upon, you know, this nature/nurture. The fact that we're more than just the sum of our DNA; we're a product of the environment that we grow up in and the interaction between the two, crucially. So even if you did make an absolute clone of a human being, they wouldn't be the same person. So really the book was a chance to explore all of these ideas and then think more broadly about how some of these methods that I describe in the book fit in the field of conservation.

I think a lot of people think about de-extinction as being very gimmicky and having no real serious place in science, or no worth. They see it as a bit of trickery; a bit of an extravagance. But I interviewed a lot of the scientists who are involved in these de-extinction projects and it's not a vanity project. There are sound ecological reasons behind why we should at least consider de-extinction and so the book for me was a chance to explore what de-extinction could do for conservation. Could bringing back extinct species be beneficial for the world's ecosystems that we have today? And how about if some of the techniques that we're using on extinct animals, [were applied] to endangered animals? How could we use some of these really high-tech cell biology and gene editing ideas in the conservation field? And that's something that's happening now. So [my book] Bring Back the King: The New Science of De-extinction actually ends with thinking to the future and how these methods can be used to help the living as well as bringing back the dead. So for me, de-extinction kind of encompasses this broad range of methodologies that can be used to bring back extinct animals and also help living animals.

A male Pyrenean ibex in the wild, peeking out from behind a cliff.
A male Pyrenean ibex peeking out from behind a cliff, photographed by French mountaineer Bernard Clos. Clos is the only person to have successfully photographed the Pyrenean ibex in the wild.

Yeah, awesome. Okay so I'd like to touch on Elvis Presley, bringing back humans, Denisovans, Neanderthals. Should we be considering the legality around it? Should we be considering it becoming a thing that will happen? What would it look like?

So the example I took in the book was Neanderthals. And I looked at Neanderthals because it's the species that we know the most about. If you're going to de-extinct anything, be it an ancient human species or an ancient non-human species, it would be wise to know as much about that species as possible so that you can get it right. So Neanderthals are really well represented in the fossil record. We know a lot about them from the artefacts that they left behind, there have been extensive DNA analyses done on them so we have plentiful sources of DNA, we've got DNA from many different individuals so there could be genetic diversity there. There's a sane theory [that] we're far more advanced in terms of human biology than we are in terms of sort of non-human, animal biology. So it could in theory be done, but the question is should it be done? And I think ethically it's very, very devious, but I also think essentially quite pointless with Neanderthals. They kind of had this reputation—which is a hangover from the Victorian era—of being these thuggish, brutish, stupid creatures that were too idiotic to learn how to survive in the late ice age. However, they were in fact pretty sophisticated early modern humans that lived for tens of thousands of years very successfully in their environment which they were really well adapted to. They did that without altering the climate, or polluting the world around them, or screwing up the planet—you could argue they were a bit smarter than us in that respect. We like to think that they were so different to us and so apart from us and that's not the case. Because the more we learn about them, the more we realize they were incredibly similar to us. If you created a Neanderthal embryo and you implanted it into some modern human surrogate and you let it come to term, you brought it up, you wouldn't be bringing it up in the late ice age, you'd be bringing it up in an era of internet and modern food and people and I think you would be massively underwhelmed because it wouldn't really be that different. I suspect [they] would have the capacity for language, for love, for family ties, and the pressure of doing it would be that on the one hand you'd think you're creating some kind of monster for human gratification—and there's an element of that probably—but on the other hand this would be a person. So it feels very wrong to do, you know.

Going back to Jurassic Park, there's that brilliant Jeff Goldblum quote [that] just because the scientists could do something, doesn't mean that they should. So I think these things are interesting in the realm of thought experiments. I like carrying the thought experiment further with things like Denisovans and really early human species that we know very little about. I think people like to think it's the equivalent of time travelling—being able just to pop back in time and see something in its original habitat—but it's not. Because the world has moved on. So you'd be seeing something completely artefactual. Ethical objections aside, medical objections aside, it would be dangerous to the embryo, there would be dangers to the mum. It's just wrong on so many levels and yet it is a really intriguing thought experiment.

I like that. Okay so you touched on this earlier. We cannot bring back dinosaurs because of the lack of DNA, but that is where people's minds go to really—dinosaurs, dodo birds, woolly mammoths. In the scheme of de-extinction, how much DNA do we need and how far back can we really go?

Okay, well the answer is you need very little DNA and then paradoxically you need a lot. You basically need enough DNA to get the whole genome of an animal. The genome is the complete genetic recipe that makes up an animal. Inside the cells of living things, inside every single cell, inside the nucleus—which is like the control centre of that cell—there's this little package of DNA. And a single cell has the complete recipe for making you. And that's where something like cloning is possible. So you don't need much at all. When I was looking into this and figuring out if we could bring back Elvis Presley, I bought a single strand—well they told me it was a single strand—of his hair on eBay. [Laughs]. I had my suspicions, it was the wrong colour for a start, but anyway. Basically from a single hair, from a single eyelash, from a single scraping from the inside of your mouth, you have enough DNA to have the genetic recipe for a person. So that's why I say you need very little material. But you also need a lot because if you are thinking about de-extincting a species, let's say the woolly mammoth, you don't want to make a single animal. What's the point in that? You don't want to make just two animals because if you then let them breed they'd end up being very, very inbred and it wouldn't be a genetically viable population. So that's why I say you need a lot of DNA. Ideally, you need DNA from a diverse range of individuals if you're talking about bringing back a collection of individuals of the same species.

And there is a time limit. When organisms die, their bodies break down and things deteriorate and the minute you die the processes that normally keep repairing your DNA and keep it in pristine condition inside your body when you're alive, they all stop. So DNA has a half-life, a bit like radioactivity. After a certain amount of time, half of it is gone. After another chunk of time, half of that is gone. And so when something is freshly dead it's very easy to get DNA, but when it's been dead for a long time it's very difficult. And fossilisation can help that process; it can slow that process. So we are able to get usable DNA, say, from carcasses of woolly mammoths that have been dug up in Siberia. They've been preserved in a permafrost for tens of thousands of years and you can get DNA from that. [It] might not be brilliant, we can come to that later, but it's a starting place. And so people have realised that there's a cut off point and that cut off point seems to be roughly about a million years ago. Now dinosaurs died out 65 million years ago, so they're too far gone. There is a really interesting scientist in America called Mary Schwietzer who has been looking at what you’re biologically able to extract from fossils of that age. She sees some evidence of proteins which is pretty convincing. She even, tantalizingly, sees evidence that there could be DNA there and possibly there could. But if you imagine DNA as this big twisted ladder, this double helix twisted ladder of chemicals, all the links in the DNA will have been decayed. So it's the equivalent of finding an encyclopaedia that's been shredded into billions of pieces—it's not really usable. So there's a cutoff point there and that cutoff point is about 500,000 to a million years ago. So that means that dinosaurs are off the cards, but things like the dodo, in theory, are on the cards. Because we can maybe get a usable source of their DNA and they died out hundreds of years ago. Woolly mammoths died out thousands of years ago, but as I say there are lots of specimens of woolly mammoth that have been turning up as the Arctic warms and the ice melts. People are able to find carcasses, carcasses that seem ridiculously fresh even with things that sort of look like fresh meat on them as they thaw. Now again, the DNA isn't going to be great, but it is possibly a starting place. Or you've got like the gastric brooding frog which was this really cool frog that was discovered in the 70s, went extinct in the 80s, but the scientists who studied it in that decade had the foresight to freeze some of these animals, some of their body parts. So again, we've got some of their cells.

So you've got a time cut off point, but you also need certain things chronologically for de-extinction to be possible. So you need a source of its DNA and you need—and this is really important—some living relative. That living relative is important because you need to borrow bits of their biology. You might need to use them as a surrogate, for example, so if people do succeed in making a woolly mammoth embryo, it would probably have to be implanted into an Asian elephant as a surrogate mum. You'd need to borrow the biology in that sense. And in the process of making a woolly mammoth, you might start off with an elephant cell, you might extract the elephant DNA and put the mammoth DNA in, but you need that elephant cell as the structure, as the scaffolding to create life in the first place. So you need all of those things, you need something to be relatively recently dead, you need a source of its DNA and you need some sort of closely related living organism from whom you can borrow bits of their biology. And that makes it sound like I've reduced it to something that sounds like a shopping list [laughs]. Each of these things is really quite difficult and quite complex. And yeah, we've got groups of scientists around the world who are brilliant people who don't see barriers and who are working on all of these different things and making progress. So there are projects out there where they're overcoming these hurdles and getting closer towards bringing things back.

What's your favourite project that's going on at the moment? If you've got one.

So my favourite one would probably be going off on a bit of a tangent.

Interior pages with the cartoon of a wooly mammoth, from the book Bring Back the King by Helen Pilcher.
Interior pages from the book Bring Back the King by Helen Pilcher.

That's all good.

When I wrote Bring Back the King,’ I asked the question, "What extinct animal would I most like to see brought back?" and each chapter looks at a different “king.” So the king of the dinosaurs, the T-Rex; the king of the ice age, the woolly mammoth; the king of the cave men, Neanderthals; and the king of rock and roll, Elvis Presley. The book looks at all sorts of different things—the Tasmanian tiger, the passenger pigeon. And I kind of thought I would end up with one of these extinct animals being my preference. Then I came across an animal called the northern white rhino. The northern white rhino is not extinct, but it's almost extinct. There are just two females left and they're called Najin and Fatu, mother and daughter. The mum is quite elderly, Fatu is a bit younger. But they both have health problems. Obviously there's no male around, so there's no hope of them perpetuating the species as it stands. They both have fertility problems anyway. So here we have a living species that is basically extinct; it's what you call functionally extinct. These animals are ghosts: you can see them, but if we continue with [the] current tried and tested conservation methods, we will lose them. And some people accept that is just the way it is.

What I realised through the course of writing the book is that these methods that people are developing to bring back things like the woolly mammoth and the passenger pigeon are methods that are grounded in medical science and can also be applied to the living. So my favourite de-extinction project is actually one aimed at trying to save the northern white rhino. So you could call it a conservation project because there are two of these animals that are still alive, or you could call it a de-extinction project if you like, because although we have two living representatives, they can't save the species by themselves. And so there are some really clever things going on here, where they've frozen sperm samples from some of the last living males before they died and they have them. You can freeze sperm relatively easily, but freezing eggs is much more complex, much more difficult because they're bigger. So they're able to harvest eggs from the last two remaining females and fertilise them using sperm from some of the deceased male northern white rhinos. And they have created little test tube northern white rhino babies, little embryos. They're getting to the point that they will need to implant them into a surrogate species and you need a close living relative, so we have another species of rhino called the southern white rhino and it's probable that that would be the surrogate species. So at some point in the future, we'll see these little northern white rhino embryos being implanted into a southern white rhino and that would potentially be a way to de-extinct this species.

So my favourite projects are actually not the ones where we're looking so far back in the past, they’re the ones where we're looking at current endangered species. And I think they're the ones to focus on. For me, they're ones to prioritise because their environment is still here. If you were to bring back a dodo, there would be some of its habitat left; however, since Mauritius has changed hugely, its environment would have changed substantially. The same with passenger pigeons, the same with the woolly mammoth, although arguably there's space for it in Siberia. So with the northern white rhino, with sort of other animals, [like] black footed ferrets, Californian condor, we need more—we need these molecular methods, we need these cell biology methods if we're going to do something significant and preserve these animals so that our kids and our grandkids can still enjoy them. And again, it's not just a vanity project; these animals are unique, they have their role in healthy, functioning ecosystems. So if we lose them we don't just lose a piece of our biological history, we take another chunk out of the ecosystem and the ecosystem becomes less and less stable. So I think it's vital that we look at preserving the biodiversity that we have that’s critically endangered.

Yes, I like that. That was actually one of the questions that I was going to ask you later on, but you've covered it, which is wonderful. Do you see frozen zoos playing into the realisation of de-extinction or just the greater conservation field?

Yeah I think frozen zoos are an unfortunate necessity. Frozen zoos are these repositories where people are storing either DNA or cells from endangered species from a whole variety of species. It would be really nice if we didn't need frozen zoos, but unfortunately I think we do and I think we need them as an insurance policy. Some people argue that if you put cells from endangered species into frozen zoos it could make it easier for us to care less about them because if they go extinct, it doesn't matter, we can always bring them back. I think that's an erroneous argument because it's not easy to bring them back. I don't think it automatically means that we care less about things, if anything I think it means we care more because we go to the trouble of thinking about and obtaining these cells. They're also incredibly useful to have because you can look at these cells and use them not just as a starting point for recreating life but to interrogate the DNA. So there's another species that I adore called the kākāpō which you will know, right?

Yep. [Laughs]

So kākāpō are arguably the best bird on the planet and are found in New Zealand—they live on a handful of offshore islands in New Zealand. There are around 200 alive at the moment, I can't give you the exact figure, but you've got a big breeding season coming up, so fingers crossed. So with the kākāpō, one of the big problems is that they're suffering from massive inbreeding—they also suffer from something that's called crusty bum disease, [laughs] which some birds succumb to more than others. Now they've done this amazing project, the scientists in New Zealand, where they've recovered DNA from all of the living adult birds. Now that's important, not just from a frozen zoo point of view, but it's important because by studying those cells, by studying that DNA, they can look to see how all of the current living birds are related to one another. Because when they're to work out which birds to put on which island, to give them the best chance of breeding successfully, they don't want to put brother and sister or brother and mother in the same space. They want to spread the birds around in a clever and pre-planned way to maximize the chance of avoiding inbreeding and increasing genetic diversity.

These cellular repositories that people are taking can answer really important conservation questions now as well. Like, which birds should be put on which islands with the kākāpō? Why do some birds succumb to crusty bum and other diseases and other birds are resilient? Is it something in their DNA? Can we learn from that? So they're really vital from a repopulating the world point of view, but more pressingly I think from a "how can we boost conservation?" point of view. The kākāpō is like the best story ever when it comes to looking at how people are throwing technology at an endangered species that's probably an entire different entity in itself. But the amount of technology and science they've thrown at this species is just so amazing and so ingenious. You know, they were down to forty birds at one point and they're really difficult birds to persuade to breed as I'm sure you probably know. They do everything possible to help themselves go extinct basically—they really haven't thought their evolutionary pathway through.

kakapo giant flightless nocturnal parrot of New Zealand, moss green mottled with yellow and black with the grey bill, legs and feet with pale soles.
The kākāpō is an endangered giant flightless nocturnal parrot endemic to New Zealand.

Yeah I heard that they also wait for a certain tree to flower before they actually breed.

That's right, yeah. So there's this [tree] called the rimu tree and it flowers every four to five years and we know it's tied to their breeding, we don't know why or how, but they only breed every four to five years. And they can pre-empt the flowering of this tree to the point now where scientists go about and they count the berries on the rimu tree and if they're above this threshold then they know that the kākāpō are going to breed the next year, and below this threshold they know that they're not. So you've got a big breeding season coming up now because there have been loads of rimu berries. And all of this is just applying science to conservation. Brilliant science.

So yeah, I got onto that from frozen zoos, but frozen zoos I think are an unfortunate necessity. We can use them to answer so many pressing questions in modern day conservation and in the future maybe they'll play their part in de-extinction also. Life is so precious, we can't be too careful when it comes to looking after it and of course we should conserve life first. Taking cells and DNA samples is such an important thing to do and so we're seeing more of these frozen zoos springing up around the world now. And while they're not much fun to go and visit when compared to a day out at a real zoo—since we're talking about tubes of cells in frozen vats of liquid nitrogen—they're still incredibly important.

In our biotech series we've covered a few topics which explore the role of CRISPR/Cas9 and the recent advancements there. In your research, you say that while we're not there yet with de-extinction technology, we're not far off. So what does a world where de-extinction is possible look like? And is CRISPR part of this? What are we missing to make this world a reality?

CRISPR/Cas9 is this genetic editing technique that lets you make very precise changes to DNA. So you can add whole genes in, you can take them out, you can tweak individual letters of the genetic code, you can make really subtle changes and it's a really important and powerful technique because it's helping us learn about human diseases; it's helping us find new treatments for human diseases. And all of these things that are developed within the medical community then spin off into other areas, and conservation is this one area where CRISPR is now being applied. If you take the woolly mammoth, for example, there are three different groups trying to bring back the woolly mammoth, that I know of. Two of these groups are using cloning technology—so the same kind of thing that they used to bring back the bacardo temporarily—where they're hoping to find a cell in a woolly mammoth carcass that is in such good condition they can simply, in inverted commas, "extract" the nucleus from the mammoth cell and pop it into an empty elephant egg. Now I think that's a really tall order because the DNA will be too badly degraded. So this is where CRISPR/Cas9 steps in.

There's a third group led by a scientist called George Church who works at Harvard University and what he's doing is starting with an elephant cell. So elephants and mammoths are relatively closely related and you can line up, on a computer, the genetic sequence of a woolly mammoth against the genetic sequence of an Asian elephant and you can see where the differences are. And CRISPR/Cas9 lets you edit those differences into an elephant cell. So it lets you “mammoth-ify” an elephant cell. And there will be millions of differences and George Church will argue that you don't need to edit in all of those differences, you really only need to edit in the ones that are significant. So we know that woolly mammoths had a particular gene for hemoglobin which is the protein that helps ferry oxygen around the body. And the particular version of the gene that the woolly mammoth had meant that they were very efficient at moving oxygen around their bodies at very low temperatures. So that would be key if we were going to bring a woolly mammoth back. We know woolly mammoths had lots of insulation; they had really thick wells of body fat and this remarkable long coat. So you would want to edit those genes back in. So that's how CRISPR/Cas9 is being used in the field of de-extinction. So you're not making—this goes back to the point that I made right at the beginning—a genetically identical copy of the woolly mammoth, you're mammothifying an elephant cell. You're making a hybrid basically. You'll make a mammothephant or an elemmoth or—this is the way George describes it—a cold adapted elephant. You're basically adapting an elephant to be able to survive in the Arctic and perform the same ecological function that a woolly mammoth did. And it will end up looking very much like a woolly mammoth and behave like a woolly mammoth if it does its job right. So the CRISPR part is there; we can actually do that. I haven't spoken to George Church in a while, but the last time I spoke to him he was racing ahead putting mammoth genes into elephant cells. That part is okay, the next part is the really, really difficult part: how do you get from a single mammothified cell to a single living mammoth? And how do you get from a single living mammoth to a herd of wild mammoth doing what they want the way they want in the wild? These are two massive, massive steps and they require input, not just from the geneticists this time around but from a massive team. They need lots and lots of people coming at this problem from lots and lots of angles.

So going back to the first point, you've got this cell with mammoth DNA in it, how do you turn that into a living animal? [Laughs] It's really, really difficult. You could use that cell for cloning, you could use some stem cell technology to maybe create life that way. This is a really significant problem and people sometimes have been able to get embryos that have been created through these sorts of methods developing, but very often the embryos don't survive. So why is that? Is there a genetic problem? Is the problem in the environment? When these embryos are tiny they're literally in a petri dish in a lab, so are the nutrients wrong? We know that the environment influences our DNA in the way our genes work, so how about the environmental cues that this thing is picking up? Maybe even though it has the right genes, those genes aren't being switched on appropriately. So these are really, really big and fundamental questions that need to be resolved. Scientists were able to make a bucardo, but it died seven minutes after it was born. Why did it die seven minutes after it was born? Now the scientists behind the bucardo project are absolutely convinced that if they had the funding and they had the time, they would be able to crack those problems. And I think they make a very convincing argument. But you've got to think about all sorts of other things too.

So there's the thing called the microbiome, right—our bodies are filled with trillions of bacteria. In fact, we're almost more bacteria than we are human and it's the same for all animal species. And we know that the microbiome has huge effects on our health, our wellbeing—this is another really active area of science—so if you bring back a woolly mammoth with the inappropriate mix of microbes that contribute to its health and wellbeing, will it even survive? So do we need to look at resurrecting microbes from woolly mammoth guts that have been frozen in the permafrost? And then suppose you have a woolly mammoth baby, suppose you have a calf and it's been brought up by an elephant mum, does an elephant mum know how to teach its baby to search for the freshest buttercup leaves under a one foot layer of snow? I'm not sure we can ask an Asian elephant to do that. They can live in the cold, Asian elephants, they live in some northerly zoos, but how will it know to be a mammoth? Mammoths, like elephants, had these complex societies that migrated huge distances; have we got enough space for that? You know, where would they live? So creating a de-extinct animal is just the start. You then create this whole raft of other things that need to be thought about and they need to be thought about in advance. And we need the buy-in of all the relevant people and we need the buy-in of society. As a society—and this gets back to the heart of de-extinction—should we do it or should we not? People will argue it could be like the equivalent of putting the man on the moon, it could be a massive wow moment for us, it could galvanize our interest in the planet and in the natural world and it could be hugely, hugely beneficial. But if you get it wrong, it could be a gimmick. It could be a Jurassic Park. So we need to think so carefully about how we pursue these ideas.

When people ask me about de-extinction, I think they automatically think that I'm really pro de-extinction, and I kind of am, but what I really am is in favour of developing the technology to the point where we have an idea of whether it's going to work. So developing all of the science around getting from a single animal to a functioning ecological herd and having that all clear in our head, which is what Phil Seddon does with all of his guidelines and stuff. So we need to think this project through from the beginning right to the logical end before we get too far down there. We need to develop these ideas and we need to have as much information as we can before we get too committed to this. So it doesn't just end with the creation of a single living animal—that's just the beginning. We need to be thinking about this tens of years down the road, hundreds of years down the road. What kind of a future are we engineering?

The second book that I wrote [Life Changing: How Humans are Altering Life on Earth] develops the idea that we have become curators of our planet and this is what we're witnessing with COP26—we are curators of our planet. We micromanage the kākāpō but actually we influence all life on Earth around us and that's a massive responsibility. So we need to be thinking about that on a global scale. We need to be thinking about it for any animals we conserve, any animals we de-extinct. And at a global scale, as we realise that our impacts are so broad and so devastating on the planet, we can't just let this coast and unfold; we need to be really, really thinking about what we're doing and we need to have decision making based on the best scientific evidence that we have. We also need society to be involved in this process; we need people to be aware. There's no point going to all the expense of de-extincting something if it's going to be a huge PR disaster and no one’s going to care and you end up with something that lives out a lonely life in an amusement park somewhere. So there's all these much much bigger questions to think about I think.

What is your biggest takeaway from the de-extinction discussion? Would you say it's just so much bigger than what we currently see it to be?

My biggest takeaway is that the key points to make are that de-extinction is very much research in progress. We're not about to see a herd of woolly mammoths stampeding through Siberia or New Zealand or anywhere else any time soon. So we're at the beginning of this process—let's not get too carried away. And the other thing is that it has to be done with a purpose. And I think there is only one valid purpose and that is that it should be useful ecologically. We need to think about [the species that we are thinking of bringing back] as part of an ecosystem, then it is worth exploring. So we need to think, is there a place for them and how would they interact in that environment? And if you bring back keystone species like the woolly mammoth, there's an argument that they could create the environment that they need, which is also interesting. But the other big take home message for me is that de-extinction isn't just about bringing back the dead, it's also about helping the living. For me that's the most exciting thing. I'm inspired by these projects to bring back the woolly mammoth and the passenger pigeon and the bucardo, but where my heart lies is in the ability to try and hang on to what we have and nurture it and turn around the fates of species that otherwise we're going to lose. In our lifetime, there could be no more northern white rhinos. To me that's not acceptable. If there is any possible way that we can use science to halt that process and reverse it, we should be doing that. We should be exploring that. People might think, oh well this is really scary stuff, gene editing, IVF for rhinos, you know, what the hell are they thinking? But what's the alternative? We do nothing and just let the biodiversity loss continue? I think just because something is difficult or new is not a reasonable argument not to try and find ways around those difficulties.

Sometimes things that are new make people feel very uncomfortable. I come back to the example time and time again of when human IVF first happened in the 70s: people were up in arms about it, people thought they were going to create monsters, there were protests. The lady who carried the first IVF baby had to be whisked away to a secret location to have her baby and we are now 40 to 50 years down the line and this test tube baby has grown up, had her own family naturally. IVF has helped millions of people around the planet. Now it's not a direct parallel with what we've been talking about, but the point I make is that sometimes things that can be new and unfamiliar and feel like a technological step too far, can be shown to be useful and safe and something that people want. That's the other thing, something that people want. And I think that's where we're at with de-extinction basically; exploring it to get to the point where we can make all these decisions.


Further reading for in-depth exploration of the world of de-extinction:

Bring Back the King: The New Science of De-extinction

Life Changing: How Humans Are Altering Life on Earth

Mary Hurley profile image Mary Hurley
Mary finds subjects which force you to dissect human-centric ways of knowing the most fascinating, and hopes to leave people questioning just why they think the way they do.