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>>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 *** neanderthalensis and *** 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.
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