For two good girl. This is the sound of legin and far too to Northern white rhinos interacting with a rhino keeper. These rhinos are mother and daughter and they live at the Old Pagetta Conservancy in equatorial central Kenya, roaming the grassy plains and woodland at the foot of Mount Kenya. They're the last of their species, the only two Northern white rhinos left. Northern white rhinos are functionally extinct.
That means they can't reproduce. There are no living males, and both in the gene and fatto team to have problems with their reproductive system. When they die, that's it the end of the species. It may seem like the rhinos have crossed the point of no return, but Richard Vine, the managing director of the conservancy in Kenya, says there's
a small hope that science can save them. The whole technique for the reintroduction of embryos into rhinos will have to be developed from scratch, so it's it's long shot. The chances of it working are small, but if the species is to be recovered, that is the process that we now have to go through. With breakthroughs in DNA sequencing, scientists might one day reconstruct the genomes of extinct species, and with stem cells, they might turn skin samples into embryos.
This is the science that makes reviving extinct species plausible. But will there be consequences to d extinction? Should scientists be doing this at all? I'm Pa Gadkari and I'm Christin V. Brown. You're listening to Decrypted. The world's rhino
population has been falling precipitously for decades. A hundred years ago, some five hundred thousand rhinos roamed Africa and Asia, according to the World Wildlife Fund, but today very few exist outside of national parks and reserves, and Richard at the Conservancy in Kenya says the black market for rhino horn is to blame, so approaching for the horn is the principal reason that rhino populations across Africa and Asia have decreased dramatically in the last sort of fifty sixty seventy years.
Sometimes people display rhinos as trophies, but usually it's the horn thereafter. In traditional medicine in many Asian countries, rhino horn is believed to be a powerful cure when shaved or ground into a powder, but these days, Richard says it's become more of a status symbol, he said. People even sprinkle in cocktails. According to one report, at the rhino market's peak, in horns, we're going for about eighty thousand dollars a kilo on the black market. That's twice
the price of gold. Those prices have fallen, but a kilo of rhino horn can still fetch upwards of twenty thousand dollars. As the rhino population dwindled in the wild, conservationists were rushing to breed the last few that live in captivity. Until two thousand and nine, Nijin and Fatu had been living in a zoo in the Czech Republic.
Now they had had a population a small population of northern white rhine those held in captivity and zoo conditions for for quite a period of time, but as it's quite common in rhinos, they had struggled to breed them regularly within the zoo as a result of their being held in zoo conditions, which are considered to be fairly unnatural. That's why these last northern white rhinos arrived in Kenya. They were moved there along with two male rhinos, which
have both since passed away. In Kenya, they could roam vast plans and live in semi wild conditions. The zoo thought it might be easier for the rhinos to breed
outside the confines of a zoo. There was quite a lot of mating behavior, but unfortunately the two females never became pregnant, and it turns out after examination of those two females that they have um they have reproductive issues which makes it difficult for them to get pregnant, which are probably untreatable as a function of age and probably as a function of their being held in captivity in zoos and not being able to breed for a long
period of time. Getting the rhinos to reproduce is all the or urgent because no Gin and Fatu are aging and now there are no living males for them to breed with, so Richard and his team began looking at another option, in vitro fertilization or IVF. It's unclear whether Nagin and Fatu are even still producing eggs, but if they are, the thinking is that egg production could be
stimulated with hormones. Then those eggs could be harvested and fertilized with frozen sperm taken from mail rhinos over the years, and from there the process would in theory look a lot like the way humans do it, fertilizing the sperm and the egg and implanting the embryo in a surrogate. The plan is extremely experimental. It's pushing the limits of reproductive technology. Even if it is possible to harvest eggs from nigin and fatu, nobody knows if this plan will succeed.
The real complication is the fact that it's never been done in rhinos before. Rhinos have a quite complex reproductive system and so a whole system for the removal of eggs are wise referred to as over and pick up has to be developed, and that is the process that we're currently undertaking at the moment. Scientists from Europe has scheduled to go to Kenya this year to see if
they can harvest eggs from nijin in fatu. Some of these techniques have been tried on southern white rhinos, which are close genetic relatives and still thrive in Africa's southern tip. So far, scientists have been able to extract eggs from a female and fertilize them. They even created an embryo that was a cross between a northern and southern white rhino, but the resulting embryos haven't yet lived long enough to be frozen for implantation. This whole plan is a long shot.
Like we mentioned, scientists don't know if nijin and fast you have eggs to harvest, and even if they do, implanting an embryo comes with a high risk of failure. But if this doesn't work, there is one more thing to try, a plan that's perhaps even less likely to succeed, making eggs from scratch from stem cells. Is it's really people are like, that's it, that's funny. There is another group of scientists also trying to save the northern white rhino.
Their home base is in Escondido, California, at the San Diego Zoos Institute for Conservation Research. The heart of their work is a place called the Frozen Zoo. I went there to visit them. The Frozen Zoo is not much to look at. It's in a windowless room at the back of an office building full of lots of big metal tanks. Those tanks are cryo tanks. They're full of liquid nitrogen and the temperature inside is minus a hundred and ninety six degrees celsius. I love this part, so
I'm glad you don't like noise. That is the sound of the Frozen Zoos curator Marlis Howk pulling a rack of slender vials filled with millions of frozen cells out of one of them. This is a bunch of different animals. So this is a box of a hundred vials, and we use color codes, so that's what you're seeing. And you can see their numbered one through ten and rows all the way down to a hundred. And then I take off the lid. Oh there they are. They Wow.
I mean, that's so crazy that just you know, here are the potential future of a species and these little teeny whiles. The Frozen Zoo has been collecting and freezing cell samples from all kinds of animals for the last four decades or so. There are more than a thousand species and about ten thousand individual animals and the Frozen Zoos collection. The zoo gets biological samples from animals when
they die or maybe have surgery or get tagged. Usually those samples are skin biopsies, and there are three full time cell culturists at the zoo who extract and grow the cells. If you keep cells at the right temperature and feed them the right food, they will just keep dividing and multiplying until there are millions of cells. On any given day, cells from forty species might be incubating in the lab. It takes about a month to grow enough cells to freeze. All of these cultures are of
cells known as fibroblasts. It's the most common cell type and animal connective tissue. Once enough cells are cultured, they can be frozen and preserved in the liquid nitrogen and revived at any point in the future. The Frozen Zoo has samples from twelve northern white rhinos, including the two that are still alive. For the rhinos, the Frozen Zoo is the last resort. Those frozen cells are the key
to an ambitious plan to save them. If you thought the scientists trying to harvest eggs from the rhinos in Kenya had an uncertain task ahead of them, the odds of the frozen zoos plan working even more unknown. Remember, the first group of scientists is hoping that at least one of the remaining rhinos will produce eggs, which can then be harvested and fertilized, but the Frozen Zoo wants to take rhino skin cells and make an egg out
of that. One of the scientists in charge of this project is Barbara Durant, director of Reproductive Sciences at the San Diego Zoo. She said the idea for this plan came from a groundbreaking technique which was first developed in Japan. Scientists were able to take skin cells from mice and reprogrammed them, changing them from skin cells into something known as a plury potent stem cell. The stem cell is a basic building block of life. These are cells that
can turn into many other types of cells. That's how a baby can start off as an egg and a sperm and develop into an embryo with blood cells and brain cells and skin cells. But these scientists managed to do it in reverse. The work one a Nobel prize. Scientists at the Zoo wanted to see if they could use the same methods to turn the rhino cells back into stem cells so they could eventually be reprogrammed to become rhino sperm and eggs. Before going I had to
turn rhino skin into rhino stem cells. Researchers had to figure out whether they had enough genetic diversity in their collection to even try it. This is a really important consideration if your goal is to bring back an entire species. They wanted it to be a healthy population and not inbred and riddled with genetic disease. Barbara believed there was enough genetic diversity, so they began their work, and so we're at that stage now, and we see that those
chloripotent stem cells are in fact colorI potent. They can be directed to differentiate into all three of the um embrhonic cell types, and they are functional in those cell types. So everything we've done so far has been successful turning those skin cells into induced pluripotent stem cells. It's a very important early step. It's quite a complex process, but
so far it's working quite well. The ultimate goal, of course, is to turn those stem cells into spermin eggs, but that's not the only thing that would need to happen
to turn those skin samples into baby rhinos. What my team is doing um in parallel with that work is we are perfecting optimizing the assisted reproductive techniques that will be needed to actually take those spermin eggs and fertilize them in the lab, grow the embryos, which is again another few, another couple of procedures that require a thousand little steps. It's not as easy as just, you know,
putting them together in vitro. When you hear it explained like this, it can sometimes seem simple, but a lot of these steps have never been done before in rhinos, so there's a fair amount of trial and error. Just because scientists in Japan were successful when working with my cells doesn't mean it's going to work with a rhino. Between species, there is a lot of biological diversity, and that means that what works for one species in a
lab doesn't necessarily work for another. But if all of that goes well, hopefully Barbara's team will have a viable embryo. The next step would be to implant the lab grown rhino embryo into a Southern white rhino, a close genetic relative. But then Barbara's team will face the same challenges as those European scientists working with the Conservancy. No one has ever done an embryo transfer in a rhino either. I asked Barbara how realistic this idea really is. I mean,
it honestly just sounds like science fiction. Yes, it's very ambitious, we understand that and the chances of failure are not not insignificant, but we do think that scientifically it is possible. Okay, Christen, So we've explained how scientists are planning to go about saving the rhinos. Now let's sum out why put all of this effort into trying to save the species that's
already functionally extinct. This is a really valid question. Not everyone thinks we should be doing this, but the strongest argument in favor of using science to bring back extinct animals is that there is an environmental benefit. Every time people really work to put a species back in a habitat, no matter how long it's been missing, there are these amazing gains to conservation. This has been novack Head scientists
and an organization called Revive and Restore. This group is undertaking some of the most cutting edge and controversial work happening in this space. He's trying to bring back the passenger pigeon which died off on the wooly mammoth, which has been extinct for about three thousand years. It's really a crucial element or restorative ecology. We want to put the passenger pigeon back in the forest for wildlife. It's not necessarily just for helping human needs and for creating
the ecological services that humans want. But the mammoth is actually about converting habitat. It's not about enriching a habitat that exists. It's completely converting habitat for very human driven needs. So Christen, what are the conservation gains that Ben thinks we're going to see? Ben gave me the example of the gray wolf and Yellowstone National Park. The wolf was hunted out of existence in the American West, but in the nineties gray wolves from Canada were reintroduced to Yellowstone.
Today the parks as wolves have made a huge difference in the local ecology. There aren't just more wolves, they are also more beavers and aspen trees. So that does sound promising, But don't you think that, well, the gray wolf was gone from Yellowstone for just a couple of generations. It sounds like a very different thing to bring back the Willie mammoth, which has been gone for millennia, right, And I should say, scientists debate how much the gray
wolf has really helped Yellowstone ecosystem. In the decades the wolf was gone, so much in the park has changed bringing one predator back can't possibly fix an entire ecosystem. Yeah, and just personally that idea of bringing back a species like the wily mammoth, which has been gone for so long, it sounds a bit like humans messing with nature in a way that could have unexpected ramifications further down the line, Right, And that's not the only argument against providing your stink species.
I also talked to Ross McPhee about this. He's one of the strongest critics out there. He's a curator at the American Museum of Natural History in New York and a paleo mammologist, which means he studies ancient mammals as usual. As it is all about some of our needs are and because we've made a mess of the planet and are continuing to do so, somehow we want to get a technological fix. So this isn't the fix. It's going
to make a difference. It's not Ras said that trying to resurrect the wooly mammoth or even the northern white rhino is missing the point fixing the wrong problem. The problem, he said, is humans, things like poaching and destruction of natural habitats. Why bring back a species from the past instead of solving the problems that continue to threaten living
species today. If you want to spend money and attention on problems that really do have some merit, and surely those are the kinds of problems that do not trying to you know, sort of thing books a post and say that you're going to bring back things in some sort of balance as they were at the end of the price to say this is this is produment. It's not anything that is ever going to happen. So he's saying it's a waste of resources that could be going
to help save species that are still alive. Ross said, it is also not clear that reintroducing law species will have any positive impact on the environment. So Kristen, I actually find Ross's argument pretty compelling that you know, even if after all this process a baby rhino is born, there will still be poaches out there who are after it's horn. Right, this is a multi pronged problem, and science can't fix everything. But you know, I'm a science reporter.
I love science, and I tend to think that his perspective is actually too narrow. There is value in the idea of science for the sake of science. You know, sure, this is expensive to do right now, and there are other species that aren't extinct that are threatened, but who knows where the science will lead or how expensive it
will be in the future. The first genome sequence caused billions of dollars, and now you can get a full sequencing for a thousand dollars or twenty three and me test for a hundreds, So who knows where this will lead? You know, Kristen, my perspective on this issue has actually changed over the course of the last few weeks that we've been working on it together. You know, at the outset, I went into this thinking much more about how saving the rhinos is a noble cause, it's something we should
be doing because it's an altruistic thing to do. But then a few weeks ago, the intake of a mental panel on climate change released this devastating report which talked about how a million different species could be at risk of extinction in the coming decades, and that really made me think about how our own destiny as a civilization depends upon the health and abundance of the natural world.
You know, the raw materials that we use for manufacturing the food and fresh water that we rely on to survive. All of these things depend on having plentiful natural habitats, and it made me think about conserving the rhinos in a different light. One thing I was thinking a lot about when we were recording this is, you know, what it means to restore something, what it means to save
a species. You know, we talked about restoring the passenger pigeon, which one extinct in nineteen fourteen, But very little of our world looks like it did in nineteen fourteen when we talked about conservation, when we're talking in these really static terms, but I think the world is really a lot more dynamic than that. So I mean, like, po, how how do you think about conservation in a world that's fluid. On the one hand, we don't want to be nostalgic and be trying to bring back things that
have passed out of existence already. On the other hand, we really do need to pay attention to save what's still left. And I wonder I would be interested to see where the further out and line some of these new emerging scientific techniques are able to, you know, once they've been tested and refined on a species like the rhino, maybe there will be a more mainstream and more potent application for it. Right, So those fight is much bigger
than the rhino. It's about saving what's left of the world's natural habitats and recognizing that we also derive economic benefit from a healthy planet. That's it for this week's episode of Decrypted. Thanks for listening. We always want to know what you think of the show. You can write to us at Decrypted at Bloomberg dot net or I'm on Twitter at Kristin B. Brown and I'm at pare Gatkari and please help us spread the word about our show by leaving us a rating or review wherever you
like to listen. This episode was produced by Pia Goodcary and Lindsay Cratterwell. Our story editor was Emily Busso. Thank you also to Akido and Vandermain and Brad Stone. Francesca Levi is head of Bloomberg Podcast. We'll see you next week.