More Science Talk
Steve Mirsky: This Scientific American podcast is brought to you by Audible.com, your source for audiobooks and more. Audible.com features 100,000 titles including Walter Isaacson’s biography, Albert Einstein: His Life and Universe, narrated by Edward Harmon, and Stephen Hawking’s, The Theory of Everything, narrated by Michael York. Right now, Audible.com is offering a free audiobook and a one-month trial membership to the Scientific American audience. For details, go to Audible.com/sciam, S-C-I-A-M. Welcome to the Scientific American podcast, Science Talk posted on April 2, 2013. I’m Steve Mirsky. This week on the podcast:
Kent Redford: No, it’s not going to be exactly the same bat, but there are going to be a lot of them and they're going to be alive and they're going to be continuing to behave like bats, expressing their batness, living and loving and eating insects the way bats should.
Steve Mirsky: That's Kent Redford, he’s a conservation biologist. After completing his doctorate at Harvard, he post-doc'd and served on the faculty at the University of Florida. Starting in 1993, he worked with the Nature Conservancy, which he left in 1997 to join the Wildlife Conservation Society. Last year, he started his own firm, Archipelago Consulting. Redford recognized that synthetic biologists are creating transgenic organisms and altering the sources of natural products to an extent that conservationists may be unaware of, and that synthetic biologists may not realize the environmental issues of some of their work. So he organized a conference that starts April 9th at Clair College in England, titled, How Will Synthetic Biology and Conservation Shape the Future of Nature? We talked about the issues the conference will address at Archipelago Consulting in Irvington, New York, about 20 miles up the Hudson from the city.
Big conference coming up, unfortunately it’s in England, unfortunately for me in New York but fortunate for people in Cambridge. Tell us a little bit about that conference.
Kent Redford: Yes, it’s – the meeting is going to take place the 9th to the 11th of April, so just a few weeks from now. It’s going to be held in Clair College in Cambridge in the UK, and the impetus behind holding the meeting was to bring together two communities of practice which had never met each other previously, yet they are about to meet each other in a very significant fashion. On the one hand is the conservation community, which has been practicing modern-style conservation for 100 years or so, and on the other hand is the synthetic biology community, which really is a matter of years if a decade or so old, and neither community really knows about the other one. And yet, they are headed on paths that are running in towards on another, very soon if not already starting.
The conservation community in my experience is – has been largely backwards-looking. That is, we – because I am one of them, are worrying about what has happened in the past, and trying to prevent extinctions, and we have largely been riding through our lives, bemoaning what we’ve lost. As a result of sitting in the back of the bus looking out the back window, we are always surprised when new things happen, because nobody told us about them until they hit us in the back of the head. Everybody else on the bus who was looking forward knew they were coming, and had had conversations and thought about it, but it was news to us. My favorite example of this is the biofuels, the rise in biofuels which was really largely unknown in the conservation community until all the sudden, it broke around us and there became this tremendous rush to try and figure out what that meant for conservation. So as, in my three decades in the field, I am tired of this happening and work with colleagues in an attempt to make sure that this time, we're looking out the front window of the bus, instead of the back window of the bus, and out of that front window, we are watching the rapidly oncoming vehicle of synthetic biology.
And so the meeting was designed as a first introduction to the two fields, one field to the other, to attempt to get the conservation community to be aware of these developments and to start to consider the potential implications, and at the same time, talk to the synthetic biology community and get them to think about the values that are biodiversity and conservation-based, that may be impacted by their practice. But also, to see whether or not there are some things that they could do to help us with intractable problems that we have been unable to address ourselves.
Steve Mirsky: Can you give me some specifics of the problems you're talking about, the intractable ones?
Kent Redford: Well, I can tell you my favorite one. I have no idea whether it would work, but it’s still my favorite, and that is the really unfortunate situation that is being faced by amphibians, particularly frogs, not all species, but a lot of species of frogs, and another issue, similar issue being faced by bats, colonial nesting – roosting bats in the US, which is the white-nose syndrome. Both of the diseases, the chytrid fungus with frogs and this white-nose disease with bats, are fungal diseases, and the bat numbers have just collapsed in really unfortunate fashions as they have been dying in the roost from this disease. In the case of frogs, a whole set of species has gone extinct and many more are threatened with extinction because of these fungal diseases.
We in the conservation community have really been able to do almost nothing about this, except document the extinctions and the population declines. There have been some attempts to bring in colonies into captivity and try to prevent the complete loss of a species, but largely, it’s really a rear-guard action. So my hope would be that there might be available, through the techniques that synthetic biologists use, a way to address these fungal disease problems. Now, when I try this out on my colleagues in the conservation community, they put their hand to their mouth and say, “Oh my god, I can't believe you're actually proposing releasing a new, genetically modified organism,” and my answer is, “Yes, that is what I am proposing, if it’s feasible and it makes sense, because in the absence of that action, we stand to lose this tremendous number of species and populations that are not only of importance to humans, but important on their own right,” and I don't know but that's the kind of thing that I’m hoping we can talk to with the synthetic biology community. And since they don’t know us, and they don’t know our problems, I seriously doubt they have even thought about this issue, and that's the – those are the kinds of conversations that I’m really hoping will take place at the meeting in early April.
Steve Mirsky: Just to pursue this a little bit, what – theoretically, what kind of altered organism are you talking about? You talking about doing something with bats, doing something with the fungus?
Kent Redford: Well, I’m not a synthetic biologist. I'm known for having ideas long before any data are available [laughter] so to me, the important thing is to ask the question of people who know the techniques, and to see whether or not they are interested and able to develop tools to address them. But in this case, it may be that changing the bats and the fungus might both be possible. So for example, it appears that the white nose syndrome fungus is found in Europe, and it doesn’t kill European bats, and it does kill North American bats. So that suggests that there may be a genetic basis that has – genetic basis for the resistance of European bats that might be something that could be available to use with these bats. I don't know, I, as – again, what I want to do is get – use that as an example of the kind of question that we would like to pursue with this new community.
Steve Mirsky: So best-case scenario, there's a gene for resistance in the European species, and we find that gene and insert it into American bats and let them breed so that they don’t – with the new gene so that they don’t succumb to the disease.
Kent Redford: Yes, and I know what immediate response is from my colleagues and other, which is, “Oh my god, then it’s not going to be the same bat,” and my answer is going to be, “No, it’s not going to be exactly the same bat, but there are going to be a lot of them and they're going to be alive, and they're going to be continuing to behave like bats, expressing their batness, living and loving and eating insects the way bats should, and who cares if it has this other gene? I don’t.”
Steve Mirsky: You don’t, but a lot of conservationists do, as you say, and there's almost a fly in amber kind-of notion that everything has to stay exactly the way it is, or it’s no good.
Kent Redford: Yeah, so it’s an interesting image you use, because it was the mosquito in amber that was the start of Jurassic Park, [laughter] so you may be stuck in the amber, but that doesn’t mean you're going to remain inert. And not that there's going to be DNA to make dinosaurs taken out of mosquitoes in amber, but the point is that our notion of what is hybrid and what is pure is really a human, value-based view of the world which is not manifested in most species. That is, purity largely doesn’t exist. The notion of what a species is, when you look carefully at the definitions, frequently involves introgression, that is genes coming from other species and mixing with this, and I gave – I was invited to give a presentation ten days ago at a meeting that Revive and Restore, the organization, put together what the National Geographic Society, called De-Extinction, and it was held at the National Geographic Society. Anyway, my talk was called Tainted Species, with a question mark, and it raised this exact question, what it is about humans that makes us really relish and desire to maintain discrete categories, while sanctioning anything that falls between those categories, yet simultaneously and against that background, still embracing things that are hybrid. And this is such a dominant human position that the French anthropologist Claude Lévi-Strauss wrote a book called The Raw and the Cooked, which is exactly about this quality in humans.
So then when we ask this question about bats and hybrids, we have to be very careful about contrasting our own desire to order the world in ways that allow us to deal with it, with the way the world itself has self-organized. And there is nowhere that this comes out more clearly than in this question of hybrids and hybridicity. One of the things that I did with the Wildlife Conservation Society was help lead the re-establishment of the American Bison Society on its 100th anniversary in 2005, and one of the major issues that we dealt with and that bison conservationists in North America are dealing with, is the fact that many bison that look like bison and act like bison are defending their offspring from wolves, are following fire to eat grass, are interacting with native species, have cattle genes in them. From a period in the late 1800s when some of the cattle ranchers, who in fact, along with the American Bison Society were responsible for preventing bison from going extinct, worked on cross-breeding. So as the animals increased, as bison increased in number to the current 500,000 or so, many of those animals have cattle genes in them. The question is, what difference does that make? And there are people who steadfastly maintain that impure bison should be eliminated, and I personally and we at the American Bison Society and at WCS took the position that if there's only a very small percentage of involvement of cattle genes, and the bison are managed in ways that allow them to express their bisonness, then we are all in favor them.
Steve Mirsky: It’s almost a eugenics-like attitude.
Kent Redford: Well –
Steve Mirsky: I don’t mean that in the sense of racial purity in humans.
Kent Redford: No, I understand that, but you look right now at the current cases being reviewed as we speak by the US Supreme Court about what makes proper marriage, and you look at the eugenics debate, you look at miscegenation laws, you look at religious intolerance, you are looking at this basic human desire to created discrete categories and to sanction things which cross over between those categories. It should come as no surprise to us that that desire on the part of humans extends into the world of conservation.
Steve Mirsky: Just to go back a little to this scenario that I mentioned about if there were a single gene in the European species that offered – that conferred resistance in the bats and we could insert that into the American species, there might be some conservations who didn’t like it. But if a mutation happened randomly that gave the North American spices the exact same gene, and then the selection pressure of the presence of the disease stabilized it in the population, conservationists presumably wouldn’t have any problem with that.
Kent Redford: Well, that's absolutely true, and even more interesting is the fact that the work that is being done on whole genomes is showing us that genomes are made up of genes from many other taxa, anyway. So you look at our own genome, homo sapiens, and it turns out we've got Denisovans, one of the early hominid genes, we've got Cro-Magnon – sorry, Neanderthal genes. Even more provocative, nine percent of the human genome is said to consist of viral genes that came from viruses. So exactly what is the worry about moving a gene from European bats? So that – we just have to look at what the background nature of what is going on, and then ask what the intervention sits in relationship to that. And then on a completely different front, we have to ask with this term is, the counterfactual. That is, what would happen if we didn’t take action, and then you ask, “If we didn’t take action, do we like that outcome better than if we did take action?” and to me, if this can be managed in ways that seem reasonable, I have no compunction about changing the genetic structure in a tiny way of bats in North America in order to allow them to continue to be bats.
Steve Mirsky: Now, what do we have to, as conservationists, then watch out for? What – when do you – where do you put the line where there's stuff that we shouldn’t be doing?
Kent Redford: I don’t have an answer to that. I don't know, but I think that what I am asking my colleagues to do is to recognize that the answer to that question is only partially a science answer, and that much of it is a human values answer.
Steve Mirsky: It’s almost an aesthetic choice sometimes.
Kent Redford: It’s an aesthetic choice, and it’s out of a sense of what you consider appropriate enough. This issue is – has come up in the – in endangered species legislation, and the question of whether or not we should be practicing what is called genetic rescue, where you incorporate genes from non-local populations in order to allow the local population to persist. That was done with the Florida panther, where because of inbreeding, small population size, there was a sense that they were going extinct as a sub-species, this is at sub-species, and that it would be all right to introduce panthers, mountain lions, pumas from Texas in order to alter the gene pool of the Florida panthers and allow them a chance to survive. That was done and it appears to have been successful, so is that a problem? Are you worried about the loss of purity, or do you celebrate the fact that there are now healthier populations of Florida panthers? And here in the northeast, the northeastern sub-species of peregrine went extinct, and the birds that were re-introduced came from six or seven different sub-species of peregrines, including all the way from Australia. Some of these birds were introduced as adults and some of them were bred with sub-species from Europe or the pacific to create offspring that were released. And we've got peregrine’s just all over the northeast and people celebrate seeing them. These huge gatherings of people staring at birds when they show up, harassing pigeons and raising babies and being peregrines. Well, they're mongrels. Does that matter? Well, it doesn’t matter to me. I'm just happy to have peregrines back.
Steve Mirsky: And you're a mongrel, too.
Kent Redford: I’m a mongrel, too. I, my – yes, that's right, Neanderthals and viruses in my genome and I'm OK.
Kent Redford: I saw a peregrine at the Rye Marshlands, and it probably flew up from I don't know, the White Stone Bridge in the Bronx connecting the Bronx and Queens, and it’s the only time I've seen a peregrine. I haven’t been looking for them very hard, but it’s the only time I’ve happened on a peregrine, and it’s a real thrill and – but I thought it was just a peregrine. I had no idea that it might have some Australian genes in it.
Kent Redford: Well, does it matter?
Steve Mirsky: It – not to me.
Kent Redford: It didn’t matter to you, you saw it and you relished that sight and the way it was acting, and to me, that’s reasonably good. Now it’s –
Steve Mirsky: But let me ask you one thing about the bison as a case, because even if you could have the pure bison again, the habitat that they lived in doesn’t exist anymore, so sometimes we look at the organism outside of its context and it comes up better when there's talk recently about the possibility of resurrecting the passenger pigeon. But the passenger pigeon has such a unique lifestyle and life history, where you need millions of them and they need a particular habitat, that the question then comes up if you could bring back one passenger pigeon, what is it? It’s not – it doesn’t live the way that they lived.
Kent Redford: Well, let’s start with bison, which is where you started and we could then go to passenger pigeons. So this species of bison, bison bison, was only one of the species that existed in North America in the Pleistocene. There were much bigger bison and medium-sized bison, and only – this is the only one that made it.
Steve Mirsky: The ones that used to be there are – were bigger than the ones that are –
Kent Redford: Much bigger.
Steve Mirsky: Wow.
Kent Redford: Much bigger, and they're gone, and this one has survived, but this one doesn’t live in the same place that it lived in the Pleistocene. So even if humans hadn’t almost eliminated them in North America, they still wouldn’t be living in the same place they'd been living then. So this notion about there being a or an habitat, and that if you don’t have that habitat then you don’t have the species, fails to understand that the word habitat means the biophysical situation in which an animal finds itself. So the word habitat has to be modified by what species you're talking about. So if you have bison living relatively in the wild, then you have bison habitat. So their habitat is there because there they are, and besides, additionally, bison ranged all the way from Alaska to central Mexico. So they are not specific to any particular kind of habitat, but they can survive – the species can survive in very different climactic and vegetation zones from high mountains to deserts in the southwest.
Steve Mirsky: They're not just on Ted Turner’s ranch in Montana.
Kent Redford: No, he’s got a lot of them. But so the thing about bison is that’s not a good one to talk about in relationship to habitat, because it has such a broad habitat tolerance. It’s much more interesting as a question when you talk about organisms like the Kihansi spray toad, which Wildlife Conservation Society has been working on breeding and releasing to the wild, and they were find – it’s a little toad, beautiful little thing that would sit on the end of your thumbnail, they're that small. And they were found only in a gorge below a waterfall in Tanzania, and the river was dammed, and the spray which came from the waterfall, which created this moist habitat where the toads were found was eliminated. So there's a case where there really was a loss of habitat. Well, so those animals are now being re-introduced to the wild by installing artificial sprayers, in order to create artificial habitat, but the animals appear to be OK, at least at this stage in re-introducing them.
So it’s not clear that kind-of a – this notion of there is no habitat, is always grounds for saying therefore, we shouldn’t do anything, and I think that's particular true of passenger pigeons. For one, we know only so much about their biology, and there is a speculation about how there need to be tens of thousands or hundreds of thousands in a flock in order for them to be able to reproduce. We don’t, in fact, know that, and the technologies that are being proposed now for restoring passenger pigeons involve cross-walking passenger genome into band-tailed pigeon. So what you end up with will not be 100 percent passenger pigeon, it'll be some mixture of passenger pigeons and band-tailed pigeons. So we don’t know what that kind of animal would need, but on top of that, at the same time, there is an effort ongoing to restore the American chestnut tree, largely through genetic alteration of the North American chestnut so that its resistance to – resistant to the chestnut blight. So maybe we will be restoring chestnut forests at the same time that we're trying to bring passenger pigeons back. I don't know, I don't think any of us know, but the interest is in trying to do something that provides a signal of hope, and to enlist a new set of people with a new set of passions and technologies to try and address the serious problems being faced by those of us in conservation.
Steve Mirsky: Part 2 of my conversation with Kent Redford will be posted shortly.
[End of Audio]
Redford is a co-author of a paper in the journal PLoS Biology [Kent H. Redford, William Adams and Georgina M. Mace, Synthetic Biology and Conservation of Nature: Wicked Problems and Wicked Solutions] that frames the issues the conference will begin to address.