Science, Ethics, and De-Extinction – AMNH SciCafe


>>Ross McPhee: The idea of de-extinction is
that we can bring back species that are now completely gone. We may, within our lifetimes,
within the next 10 or 20 years, see species that have been brought back from perhaps just
yesterday or perhaps hundreds or even thousands of years. It’s a bit Brave New World-ish.
It’s certainly unexpected that we’ve moved so far along with biology that we’re able
even to consider this sort of thing. Now, the term “de-extinction” does not
have an explicit meaning yet. It’s rather loosely defined to cover entities all the
way from populations or species all the way up to entire ecosystems. The idea that you
can recreate worlds that are lost or at least misplaced by virtue of modern science. Another aspect about de-extinction that occurs
to me is that, in a sense, it’s more like theater at this point than it is about nature.
And by that I mean, you’re going to be asked to willingness suspect your disbelief, just
as you would watching a play, when eventually we see some of the products of de-extinction
methodology. Consider dioramas at a place like this, like
the American Museum of Natural History. The dioramas are real enough, but they’re parts,
they’re not wholes. It’s not life but mimicry of life that we’re talking about.
Imagine that you’re gazing over New Jersey 10 years from now and you see mammoths. Or
something that looks like mammoths. Or mammoth-like elephants. Well, what are they, really? What
they are really will be facsimiles. They’ll be replicas of what existed no sooner than
10,000 years ago. They will exist as the result of human artifice. I’m saying it that way because there is
a break between the last mammoths that were here naturally and the present day. So what
we will create may look phenotypically—that is, an external appearance—like a mammoth,
may act differently from an ordinary elephant—we’ll ascribe that to its mammoth-ness, I guess;
but in many respects, it needn’t be and perhaps won’t be the same. And that raises a number of issues. I’m
going to talk about three ways that people are now thinking of doing de-extinction. One
is artificial selection, the traditional kind of thing that humans have practiced for 10,000
years or more, selecting for features that they want in species that they’re interacting
with. A second is reproductive cloning. You perhaps
all remember Dolly the sheep, she was the first of several efforts—in fact, many efforts
now, to clone advanced creatures like vertebrates from adult somatic cells. And then, finally, synthetic biology, which
is really the techie gorilla in the room. This is what’s going to change our lives
in ways that are scarcely imaginable. This is actually creating life out of building
blocks, much like an engineer might create a building. I have one overriding ethical issue which
will come up again and again, so I’m going to speak about it now. My greatest concern
about de-extinction is not whether it’s done, but how it is done. And what it means
to bring back species, populations, individual animals that, for all intents and purposes,
are not part of the modern fauna. “In the case of de-extinction, what we’re
really talking about is undertaking a whole lot of unplanned experiments, the consequences
of which are very hard to predict. We don’t want a situation in which we drive out species
that are perhaps already endangered, thanks to us, with something else that we drove to
extinction thousands of years ago. That makes no sense. That’s not a successful strategy
at all. “The way to think about this instead is
that de-extinction, to the degree it will take place, should be limited in its scope,
limited in its ambition, limited in the kinds of species that we bring back.” I’m now going to talk about the top ten
things that I think you ought to hear about de-extinction. And let’s start with #1,
which is why should we even try to de-extinct anything? A first reason is, Hey, we think we can do
it. We’ve got the machines. We can run whole genomes of individual organisms, as long as
they’re not too big and [in] the space of an overnight experiment. Another reason: It’s our fault, isn’t
it, dammit? That they’ve gone extinct. I’m introducing here this in terms of an idea
in the philosophy of law called restorative justice. What that is is that embodies the
idea that the victim ought to be restored to the condition that he or she was in beforehand
before the wrong occurred. In other words you as perpetrator have to heal the wrong,
not just pay a fine or go to jail or something of that nature. For species that are still with us, an example
of restorative justice might be to recompense them in some way for the lands that we’ve
usurped from them by increasing their ranges, by setting aside range. For extinct species,
it’s going to be more complicated. Perhaps for species that became extinct because of
human activities we ought to feel particular obligation. We ought to provide them, in short,
with new lives. And that’s what the idea of de-extinction carries with it. Yet another view: Because we can bring back
entire ecosystems. Now, what does this really mean? What dates are we talking about? In
this country, are we talking about 1492? Are we talking about 10,000 years ago, before
the big Pleistocene extinctions? What do we mean when we say we want to restore entire
ecosystems? There’s those who believe, for example,
they’re called “rewilders” and the idea is rewilding, that today we live in the ecological
wreckage left over from the disappearance of some 70 species among mammals alone, about
an equivalent number of birds that died out in these big extinctions at the end of the
Pleistocene. And their feeling is that we could “rewild” America by introducing
species that are either the same as the ones that have disappeared but survived elsewhere
or, nowadays, through de-extinction. We can bring back the mammoth, we can bring back
ground sloths, we can bring back whatever you want. Reinstall them and go back maybe
10,000 years. By virtue of being engaged in efforts to de-extinct
things that are no longer with us, there’ll be a lot of work done. There will be payoffs.
And those payoffs might be utilized for protecting and enhancing the lives of species that are
merely endangered, not just dead. This is the whole idea of facilitated adaptation.
To give you some examples: Could we not, perhaps, with modern technology, introduce genes that
will provide resistance to malaria in Hawaiian honey creepers, which have been devastated
by avian malaria? Could we not find a way to introduce genes that would make it easier
for female pandas to give birth successfully? Live births. These are important conservation-related
questions. They usually have nothing to do necessarily with de-extinction, but the idea
is that by being involved in such studies, that might be one of the payoffs. And, finally, and of course, why not? For
the money. For the power. For the fame. And I ask you, who wouldn’t give five bucks
to pat the butt of a thylacine? I would. Who wouldn’t want to feed a dodo, if you could?
With, of course, the right kind of bird food. So, the next question is how might de-extinction
really work? What could we do that would in fact bring back extinct species looking like
they did, acting like they did and, presumably, surviving like they did. This is what humans
do. We go into nature, we find products or entities that we like because we can eat them
or utilize them in some way. And then we breed them. We breed the most desirable individuals
to get what we want. Whether it’s chickens or apples or pansies. What you see on the
screen now is a cave painting from Lascaux in France, of bos primigenius, the aurochs.
This is a member of the cattle family, closely related to our cattle, but yet different from
it. There is, among the rewilders, an interest
in back-breeding cattle that we have today, who presumably still carry some of the same
genes, to recreate the aurochs. Now, why would they want to do such a thing? How would they
do such a thing? That’s fairly simple. It’s breeding for what you want. The character
of the horns, the hide color, size, things of that nature. And they’ve had some success.
They now have animals that for most intents and purposes look very aurochs-y-like. Their
view is that there’s a reason to do it for ecosystem recovery. We’re used to I think
thinking of Europe as being a land of forests from Spain as far as you wanted to go, because
that’s how the ancients described it. Their point is that, if you went back to the
Pleistocene, it would not have looked like that, because you would have had all of these
large herbivores. Grazers, browsers, manurers, who would have kept down the forest, much
as elk and deer do in parts of this country nowadays. There’s so many of them that they
eat the saplings. And as a result, develop large, open spaces within the forest. So the idea here would be—this is another
reason for de-extinction, to return as far as you can, if you will, Europe to how it
looked. Whether they will be successful or not is a completely different question. It is true that you can phenotypically, as
in the case of aurochs-like animals today, get back to something resembling probably
what they looked like. But you won’t be able with any certainty
to recover behavior, because nobody knows how aurochses behaved. And you don’t know
other things, too. Resistance to disease, an important feature. And, as I’ve already
mentioned, what exactly do you mean by recovering the collapsed ecosystem? Which ecosystem?
When? Another way, through cloning. Very briefly,
what this method envisages is that you take a genetic material, the nucleus of one cell.
You put it into another, an egg. And that egg is then placed in an animal that will
act as surrogate mother and produce an offspring. You get Dolly. Now, Dolly didn’t last too
long. She lasted about six years, but for her breed or at least the breed of her donor,
it should have been six to 12 years. So what happened to Dolly? She developed lung cancer,
which is common in that particular breed. But it’s an age-related thing and they usually
don’t show features related to cancer until about the ages of 11 or 12. She died young. One view is that she actually started out
at 6 years of life, which was the donor’s age. Her cell, the one that was used, the
egg, was already in a genetic sense 6 years old. So she had her life span, but it was
contracted in terms of her actually being on the planet. She also had other physical problems. And
in fact so it is with most of the cloning efforts that have been tried. There’s actually
a large number of different species that people have attempted using adult nuclear transfer.
And most of them have been one-offs. And the reasons are simple. Most of the clones are
not very healthy. Most of the clones don’t last very long. Most of the clones don’t
reproduce very easily. And, for that reason, as a method of de-extinction, it’s probably
not going to go anywhere unless there’s vast improvements about which we know nothing
at present. But I do need to mention, don’t I—since
I’m the mammoth man here—about the efforts to clone mammoths. This started in the late
90s, largely because of the success with Dolly. And the idea was, all you really need to do
is go to Siberia, find yourself a mammoth carcass, extract a cell, a viable cell, presumably.
Take it back to the lab, do the whole cloning technology that I described for Dolly. And,
before you know it, out of an Asian elephant, you get your baby. A hybrid mammoth. Well, the reason why you have heard nothing
about success in this quarter is because nothing has happened. And here is a really good reason
why. This is what they mostly look like. This happens to be an extremely well-preserved
mammoth mummy from Siberia. It’s a lot more like a road pizza than it is anything else
and the chances of getting anything viable out of it are effectively nil. And the reason
is because the DNA degrades. The bones break, you get smaller and smaller fragments, there’s
no energy coming into the cell to keep things together, it’s dead. That’s a medical
term. Okay, let’s get to the crux of things now.
Synthetic biology. Because this is different. You’re using the materials of biology, rather
than cement and steel to make things. What you’re making in this case are genes, synthetic
chromosomes and in that way finding a way for creating life. Some of that life may be
de-extincted life. Some of that life will probably be things that never existed before.
The drug companies are interested because it’s a way of making vaccines out of bacteria
that are programmed to do the work. It’s a way, perhaps, in future of getting petroleum.
There are bacteria that have been genically tricked into producing petroleum. Not in large
measure at this time, but that’s what’s going to happen eventually, probably. The
idea is that synthetic biology is going to be the future. It is going to be terribly
important What I want to talk about very briefly is
an effort to bring back the passenger pigeon, which is an extinct bird, that disappeared
almost exactly a hundred years ago. Passenger pigeons have several very close relatives
among pigeons and one is the down-tailed pigeon, which is very close indeed. In recent years, scientists have been isolate
the differences between the genomes of extinct passenger pigeons and living down-tailed pigeons.
They have been able to inject these novel sequences into the germ line of developing
down-tailed pigeons. And using surrogates with the sex cells of passenger pigeons, if
you crossbreed them one to another, you will in the next generation get something that
should look exactly like a passenger pigeon. Now, is this feasible? Technically, it certainly
is. But with regard to all of the species that one might want to think about, there
are other issues. So one thing that is clear is birds are going to be easier than mammals,
because with birds, they’ve got external eggs. You can do a lot of manipulation that’s
really not possible or not easily possible with mammals. It’s also going to depend how recently they
became extinct. So this Christmas Island rat, which is very close to me, because I studied
it, has living relatives. And everybody, of course, would like to see more rats in the
world. But it only died out in 1888 or thereabouts. So the chances are that there’s some possibility
of recovery. Size matters. For the surrogates. And the
idea with mammoths is that you would get the developing embryo into an Asian elephant to
which mammoths are closely related. You’d probably still have to do a caesarean rather
than natural childbirth, but the idea is that it would nevertheless work. It’s not going
to work, I’m sorry to say, with ground sloths. These guys came in at four or five tons. They
are hundreds of times larger as adults than the largest living tree sloths, which come
in about 5 kilograms. Not going to happen. I want to go on to ethics, because we don’t
have de-extinction now. You can say with regard to back-breeding, but in a technical sense.
What we have now is that we’re perched on the cusp of being able to do it. And shouldn’t
we, accordingly, think through what it’s going to mean. We would not want these de-extincted
animals to be kept in a zoo-like place or under rigid confinement. We would want instead
something like what they lived in, to the degree that we can emulate that. But consider:
Say we took mammoths and put them onto the Great Plains, where mammoths once lived. That’d
be fine. Except, what happens if you get a really bad winter and a lot of them die? As
happens all the time to large mammals on the Great Plain. Doesn’t make any sense to have
several large species of herbivores that used to live on this continent wandering around,
outside Duluth, crossing interstates—right? Not a good plan. Now, we can run kind of a thought experiment,
which I’m going to ask you to perform with me. Is there any species out there living
in the U.S. now which we could identify as a result of rewilding and draw lessons from
it as to what might happen in future? Now, one thing you’re probably thinking
of bison. Bison was certainly brought back from the brink of extinction. It’s now,
for all intents and purposes, recovered. That’s not the one I want to talk about. This is
the one I want to talk about. The horse. Bison are newcomers. They came
into North America about 125,000 years ago. Horses, the family Equidae, evolved here in
the Eocene 50 million years ago. And there has not been a geological epoch since then,
except for the last 10,000 years, that we didn’t have horses. Ten thousand years ago,
they disappeared with the mammoths. As I’m sure you all know, they were introduced 500
years ago by the Europeans. Numbers over time became feral. We call these in the West nowadays
mustangs. They occupy parts of Wyoming, Oregon, Montana. On Bureau of Land Management land, where they
are mostly concentrated, it’s felt that they are an invasive species. You can see
that on their website. And every year, there’s a culling operation. Helicopters are used
to drive the animals into confined areas where they are evaluated and a certain proportion,
most of the time, are taken out and euthanized. Now, there are management issues. I’m not
ignoring that. But this is a species that used to live here. This same exact species
evolved in North America. And we regard it now, some do, as an invader. Would the same
thing happen with mammoths? We can do all this work? Why couldn’t we
bring back Neanderthals? After all, they’re something like four to six percent of our
genetic makeup that is Neanderthal-derived. What this means is homo neanderthalensis and
homo sapiens are inter-fertile. So what would it be like to bring them back? What would
it mean? Would they be regarded as fully human? Half-human? Three-fifths human? Would they
be patentable as intellectual property? The U.S. Supreme Court just last year decided
that stem cells, because they are in fact products of nature, were not eligible for
patenting. So perhaps in this case, that wouldn’t happen. Should they, could they have full
citizenship in this country? Be allowed to vote? Live next door? Should they, could they
be restricted in their mating opportunities? And, if unrestricted, how are the hybrids
going to be treated? A final point, the last of my top ten. There
is a feeling in the conservation community, which I’m very well aware of, that this
kind of attention to de-extinction, bringing back these animals, how is that going to indirectly
or directly affect conservation activities, conservation funding? There are some people
who argue that this is exactly what conservation biology needs. It needs to stop being a nostalgia
trip, trying to conserve only, and you get people more interested if there’s something
else going on. If you could bring back mammoths, would that not mean that there would be abundant
and new interest in conserving what we have, in making it better, in doing that restorative
justice thing that I mentioned at the outset? The counter to this, and it’s a valid one,
is that just bringing back a few mammoths or a few of whatever, is not about conservation
at all, but it’s a further example of human manipulation of the biosphere, which we haven’t
been very good at, have we? And if I have a parting message on all of
this for you, it is don’t just fear and loathe the idea that synthetic biology’s
going to change your life. But instead, just like with anything else that’s important
to you, try to grapple with the big questions, try and find your own answers. Try and speak
out or speak with or carry on imagining what life would be like under conditions like the
ones that I’ve outlined today, where we know now so much that we’re able to play
god, but still don’t have the omniscience thereof. Thank you. End of audio
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