IRA FLATOW, host:
This is TALK OF THE NATION/SCIENCE FRIDAY. I'm Ira Flatow.
The North America of the past was not like the North America of today, and I don't just mean strip malls and subdivisions. The basic ecology was different. Go back just 13,000 years or so, and you'd find, roaming free, large animals similar to those you'd find in zoos or wildlife preserves today. North America had species related to wild horses, camels, lions and even elephants. Now what if--What if?--we could have them back again?
Writing in a commentary this week in the journal Nature, a group of ecologists propose that--what they call the Pleistocene re-wilding, trying to reintroduce large wild animals back into the landscape, animals that were last seen here thousands of years ago, or to introduce close relatives of extinct species, trying to fill their same ecological niches.
Does that sound crazy to you? Do you think we should have camels in Kansas and cheetahs zipping across Nebraska? What do you think?
Joining me now is Josh Donlan, one of the authors of the paper and a graduate student in the department of ecology and evolutionary biology at Cornell University in Ithaca. He joins us from the studios of member station KQED in San Francisco.
Welcome to SCIENCE FRIDAY.
Mr. JOSH DONLAN (Graduate Student, Department of Ecology and Evolutionary Biology, Cornell University): Thanks for having me. It's a pleasure to be here.
FLATOW: How--it's hard--I don't think very many of us realize what was roaming around here these many years ago. Was that during--before the last Ice Age?
Mr. DONLAN: Right. This is--our vision of this plan uses, or strives to use, ecological history to inform conservation action or conservation plans. And when I talk about ecological history, we're talking mainly about the Pleistocene. Now the Pleistocene is the time period starting two million years and coming up to about 13,000 years ago. In particular, we're interested--or our benchmark we're talking about is right about 13,000 years ago, where North America was a very different place. We had our very own lions, cheetah, camels and lots of large mammals, not unlike Africa. In fact, it was more diverse than Africa 13,000 years ago. And we lost, in the blink of an eye, over 60 species larger than a hundred pounds.
FLATOW: What? Because of the Ice Age?
Mr. DONLAN: Well...
FLATOW: The ice killed them all, or what?
Mr. DONLAN: More and more evidence now points to humans playing a significant role. This has been a big debate in ecology and paleontology over the past 40 years, since Paul Martin came up with the idea of Pleistocene overkill that it's called; that is, when humans came over to North America for the first time, they played a role in this extinction. Over the past 30 years, not only in North America but throughout the globe, more and more evidence is pointing to humans playing a major, if not a significant, role in these extinctions.
FLATOW: Now give me a scenario for how you would repopulate the area.
Mr. DONLAN: Well, we're interested--we know from long-term studies in Africa, long-term studies in North America and elsewhere, that these large mammals play very important roles in the ecosystems; that is, the processes that these large mammals are involved--predation, herbivory and just interacting with their environment--often play extremely important roles in terms of maintaining biodiversity and structuring ecosystems. So when we lost these large mammals in North America, one has to ask the question: What were the ecological consequences of losing that ecological function, if you will? We're arguing, through science and taking a science-based approach, can we use closely related species to help in an attempt to partially restore these lost processes that these large mammals are responsible for that were probably very important to the biodiversity of North America?
FLATOW: Well, you haven't told me where you'd put them and what animals and how you'd get them there and things like that.
Mr. DONLAN: Well, this would all be staged process, in terms of starting in the now and spanning the coming century. One of the big misrepresentations that's been happening in the press over the past few years--I mean, over the past few days; excuse me--is that people are saying that we're arguing stealing Africa's animals and moving jeopardized species from Africa back to North America. This is not the case, while we are arguing that some of the closely related species to our North American species are the cheetah, for example, and are elephants--that is, the African cheetah is very closely related to the Asian cheetah. Asian and African elephants are the closest living relatives to the five species of elephants that were here in North America.
But we're arguing to take a science-based approach, to use captive populations in the United States, or populations that are already present here in wild game parks, such as Texas, and potentially use small, experimental reintroductions into protected areas.
FLATOW: Give me a scenario of an area and a protected area, because I have trouble, and I think my listeners might have trouble, imagining elephants and lions roaming wild in Kansas or the other Plains states. Where would they be? Where would you put them? How would they survive the people who'd be in their cars and things like that?
Mr. DONLAN: Right. The--obviously, there's a lot of unknown questions here, and that's why we've been arguing for a science-based approach, a step-by-step process, so we can learn as we go along. I can give you an example of how the--would be the first steps in terms of what could happen now, in the immediate time period. If we go back 13,000 years ago, there was a large tortoise, weighing up to a hundred pounds, found all across the Southwest--Arizona, Texas and New Mexico. Thirteen thousand years ago, that tortoise was drastically reduced in terms of its distribution, and today it's critically endangered in a small area of Mexico.
So reintroducing populations to North America offer huge not only conservation benefits, but also cultural benefits. Honey would be able to take her kid to see these large tortoises...
FLATOW: I understand this, but if you're...
Mr. DONLAN: Right.
FLATOW: ...not able to describe how you can do this, how are you going to do--how are you going to get interest in this if you can't describe how you're going to go about doing it?
Mr. DONLAN: Describe it in terms of how it would actually happen?
Mr. DONLAN: So we were--we're arguing that first we start with things such as tortoises, and then we take a science-based approach and, say, take a protected area or take, say, a private ranch, for example, and then reintroduce these potential species that play very important roles. Take pronghorn, for example, which is a deerlike animal that's found throughout the Western landscape. Now we know that--and the pronghorn are actually one of the fastest land mammals in the world. We know that the pronghorn's astounding speed is a direct result of four million years of predation by American cheetah. So one could ask the question: Could we restore that strong interaction between pronghorn and cheetah by reintroducing African cheetah to potentially play that same ecological role?
And these are all questions that would be answered by science in a research-driven approach. By no means are we advocating backing up a van and taking out a van full of cheetah back onto the landscape.
FLATOW: We never suggested you were. (Laughs)
Mr. DONLAN: Right. Right. Right. Oh, I know.
FLATOW: Well, you're visiting us with the sins of other people. 1 (800) 989-8255. Let's go to Andrew in Ithaca, New York. Hi, Andrew.
ANDREW (Caller): Good afternoon. Can Josh tell us where he got the word `re-wilding' from? Surely `reintroduction' is better. We are trying to elevate the standard of our students at Cornell in Ithaca.
(Soundbite of laughter)
Mr. DONLAN: Great question.
FLATOW: Somebody who must know you. Go ahead.
Mr. DONLAN: Actually, `re-wilding' has an interesting history, actually. The word `re-wilding' was coined in the early '90s when Dave Foreman and Michael Soule, conservation biologists, formed the Wildlands Project. And they articulated a vision of a series of network reserves, private land, protected land, from--spanning the entire continent, in an effort to preserve the nation's biodiversity. Our proposal is actually termed `Pleistocene re-wilding,' as referring to Pleistocene, pushing back our conservation benchmark; that is, where do we aim to restore to? We're saying that 13,000 years ago, while maybe not--while clearly not an appropriate benchmark for many places in the United States, it should be debated and in some places it might be a very valid benchmark in terms of where we aim to try to restore our biodiversity in North America.
FLATOW: Mm-hmm. Let's go to a quick phone call. Is it to Cecile in San Francisco? It's Caroline. I'm sorry.
CAROLINE (Caller): Hi. I just was--just wanted to make a comment and maybe a quick question concerning the fact that I think that the concept here is a little farfetched. It seems to appear that we're just looking at large animals and not small rodents and all the vegetation that these creatures may need to feed upon, regardless if they're in an actual wildlife refuge. I just think that that might not work at all and if that--even, then, taking into consideration the science.
Mr. DONLAN: She brings up a good point in the fact that, over this past year, since we've been trying to articulate this framework, we found when we talked to this idea--when we talked to people about this idea for five minutes, they think we're nuts. When we sit down and talk to them about it for about an hour, they start to see the value of trying to think beyond into deep time; that is, thinking back thousands of years ago and what the biodiversity was like in North America then, and what does it mean--what does all that biodiversity that we lost--what does that mean in terms of conservation?
In terms of the caller's comment on what--that small mammals and the plants might be different in terms of what it as 13,000 years ago, if you look back 13,000 years ago, that's really not the case. We see this huge extinction then of large mammals, but we don't see any real plant extinctions or small mammal extinctions. And so we're arguing that we need to think farther back than Columbus. Right now in conservation biology, the de facto benchmark--that is, what we're trying to restore to--is 1492. That doesn't really make much sense anymore, in terms of now we know earlier Americans were having large impacts on our biodiversity, and we lost most of our biodiversity back beyond 1492.
And so when we're thinking about restoration, one good example is to think about wolves. Despite what you hear, most Americans are behind the reintroduction of wolves.
FLATOW: Hold that. Josh, hold that thought on wolves...
Mr. DONLAN: OK.
FLATOW: ...'cause we have to take a break, and we'll come back and talk more about wolves and take more phone calls and talk about steps you might take toward re-wilding North America. Stay on the phones. We're talking with Josh Donlan, a graduate student in the department of ecology and evolutionary biology at Cornell, talking about lions and tigers and--bears are here already, so we've got them all already. Stay with us. We'll be right back.
I'm Ira Flatow. This is TALK OF THE NATION/SCIENCE FRIDAY from NPR News.
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FLATOW: You're listening to TALK OF THE NATION/SCIENCE FRIDAY. I'm Ira Flatow.
We're talking this hour about reintroducing animals that used to be living in North America till about 13,000 years ago, animals that you'll find now in zoos and wildlife preserves--reintroducing them back into their native habitats here in North America. And this idea is being proposed by Josh Donlan, who wrote a paper in Nature describing it.
Josh, can you give us a place where--you said it might start out on a ranch someplace, right? Give us a scenario, over decades, of how the introduction might happen.
Mr. DONLAN: Well, we see it as potentially happening first on private lands; that is, large, private ranches and other property, perhaps in the Southwest, where these lands exist, with owners that are interested in biodiversity conservation.
FLATOW: And people like who...
Mr. DONLAN: Moving out--I'm sorry.
FLATOW: Yeah--like--and sort of making the reintroduction--you mentioned wolves, and we've seen the buffalo and the bison come back. You're just talking about expanding that kind of idea.
Mr. DONLAN: Exactly. And we're arguing that not only is there a scientific justification for this, but there also might be economic benefits, as well, to ranchers that are potentially looking for alternative economic avenues.
FLATOW: Mm-hmm. 1 (800) 989-8255. Marty in Ann Arbor. Hi, Marty.
MARTY (Caller): Hi, Ira. I'm an ecology student at Montana State University in Bozeman, Montana, and my question for Josh is: How would he suggest that we assess, through the geological record, what niches or ecological roles these species that are now extinct actually filled? And how would he suggest seeing that there's some sort of continuity between those proposed niches and the niches that--these animals he's suggesting introducing into the American Plains.
Mr. DONLAN: That's a great question. That's a great question, because, obviously, the niche--that basically is a word for what role does an animal play in its environment--isn't captured in the fossil record, so we can't go to the fossil record and say, `What were the five species of elephants doing in America?' What we can do is go over to Africa and Asia, where there are existing elephants, and look at the role they play there through long-term research, which has been done. And we know that elephants play tremendous keystone roles in their biodiversity.
Then we can go back to North America--and people have done this. People like Dan Janzen and others have looked at plant characteristics and looked at the fossil record, and have deduced--although it's not hard data in terms of the data we have in Africa, you can deduce from the overall picture that these large mammals almost certainly played very important roles. And that doesn't mean that the Asian elephant, if we bring it back over to North America, is going to play that exact same role. We're arguing that we can try to answer those questions with science by doing this at the same time.
FLATOW: OK, Marty?
MARTY: Yeah. That's a very interesting project. Thank you.
FLATOW: Thank you. 1 (800) 989-8255. It's hard to believe that there were elephants roaming around this country or this continent. Where were they? Could you describe what parts of the continent they were on?
Mr. DONLAN: There was roughly--well, there was five species of elephants all across all of North America and South America 13,000 years ago.
FLATOW: Hmm. And you feel that they may have been hunted out of existence.
Mr. DONLAN: More and more evidence is pointing to a significant role of humans--humans playing a significant role in terms of the extinction event, not only hunting, but also probably indirect effects, as well.
FLATOW: Mm-hmm. Is there a possibility that if they get developed here they might turn into an invasive species and wreck the countryside?
Mr. DONLAN: That's going to be a clear concern, and there's definitely potential for unexpected ecological consequences from an invasive-species context. What we're arguing--and I actually spend half my time trying to remove species from islands as conservation, so I'm well-versed and well-versed in the invasive-species concept. But we're arguing that what's different here is the species that we're proposing to restore are supported by the fossil record and supported by ecological history.
Let me give you an example. Goats on islands in the Galapagos--never, in the thousands of years of the Galapagos have they had a mammal herbivore like a goat, so goats get introduced onto the Galapagos and they have huge biodiversity impacts and ecosystem degradation. So it's justified to remove those animals in an effort to conserve the biodiversity in the Galapagos, compared to North America, where we had cheetah...
Mr. DONLAN: ...and we had elephants.
FLATOW: Right. 1 (800) 989-8255. Let's go to Sierra in Tallahassee. Hi, Sierra.
SIERRA (Caller): Hey. Yeah, I had a couple of questions and comments. I'm in Tallahassee so, you know, we have to deal with the Florida panther here, and they're always having trouble trying to keep its population up. So I wondered, like you said, Ira, about, you know, it being an invasive species and it taking over niches that are currently filled by other things that are local. And the other--the question I really had is--I think I've heard that there is, like, woolly mammoth DNA available. Are you guys considering doing anything like a "Jurassic Park" thing, where you actually...
SIERRA: ...create some of them? I mean, that would be really cool.
FLATOW: Yeah. And...
SIERRA: Not that it's not neat to try and keep--you know, try and salvage the animals in Africa from becoming extinct by giving them other places to live, but bringing back ones that are already extinct would be really...
FLATOW: You'd like to see a woolly mammoth on Route 1, wouldn't you?
SIERRA: I would love to. You got it.
(Soundbite of laughter)
SIERRA: We've got a six-feet one that's, you know, all bones down in downtown...
SIERRA: ...and I'd love to see a real one.
FLATOW: Can you imagine the traffic cop to report--when that...
(Soundbite of laughter)
FLATOW: All right. But OK, let's talk seriously about it. What about it, Josh? Why can't you--there must be DNA from some of these species still around, right?
Mr. DONLAN: Well, researchers are definitely getting better and better at pulling DNA, ancient DNA, out of samples and out of fossils, out of fossil bones. And there was an attempt to try to extract DNA out of a frozen mammoth a few years back. It's an extremely complicated process, and I think they're probably at least a little bit, if not a long ways, off in terms of being able to do that.
FLATOW: Mm-hmm. But would that be something you'd look for--I mean, you know, try to find some DNA? You're talking about a century now--doing this over a century. I would imagine that technology, biotechnology, over the course of a century might be improving to the point where you could extract the DNA.
Mr. DONLAN: It definitely is improving, and we'll have to see--we're arguing that we should use extant, living, closely related species from Africa and elsewhere. I should also say--point out a comment to the caller that we're not suggesting a primary role of this plan is to steal--or not steal, but try to save Africa's wildlife from extinction. We definitely feel that the best place to save Africa's wildlife is in Africa. But we are arguing that there's--North America's empty, to a certain extent, and perhaps some of the African species that are closely related could help fill those roles.
FLATOW: But if you could resurrect a native species that's extinct by its DNA, how much better something native than bringing a relative from Africa.
Mr. DONLAN: Definitely gets you thinking, huh?
FLATOW: (Laughs) You know--but I'm surprised you're not jumping on that concept, for some reason.
Mr. DONLAN: Well, I think we're a long ways off, and I think, you know, there's a lot of obstacles to that, both scientifically and ethically.
FLATOW: Mm-hmm. Well, I want to thank you for taking time to talk with us, and we'll be watching, and sounds like an interesting project.
Mr. DONLAN: Thanks for having me.
FLATOW: You're welcome.
Josh Donlan is a graduate student in the department of ecology and evolutionary biology at Cornell University in Ithaca, and co-author of one of the papers--author of a paper published this week on the idea of Pleistocene re-wilding that was published in Nature.