DE-EXTINCTION: Molecular paleontologist Beth Shapiro spoke at the recent TEDxDeExtinction event, warning how difficult it will prove to resurrect the woolly mammoth.
Image: Courtesy of TEDxDeExtinction
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WASHINGTON, D.C.—The rebirth of an extinct frog species may come from the freezer, not the stomach. The gastric brooding frog, when it existed on Earth, swallowed its eggs, transformed its stomach into a womb and vomited up its young once sufficiently grown. But the frog disappeared from the mountains of southern Australia shortly after it was discovered in the 1970s, persisting only as a few frozen specimens in the bottom of a scientist's freezer.
The cells in those tissues should have been ruptured by the swelling ice crystals that formed within and around them. But some of the cells remained reasonably intact, according to paleontologist Michael Archer of the University of New South Wales in Australia, who is attempting to resurrect the species via his Lazarus Project. He and his colleagues transplanted the nucleus of that cell and others like it into hundreds of eggs from a closely related species. "Last February we saw a miracle starting to happen," Archer announced for the first time to the crowd at the TEDx De-Extinction event on March 15 at the National Geographic Auditorium. "One of them began to divide." (Archer’s group has not published the work yet.)
While tadpoles may be a long way off, let alone a viable frog, the southern gastric brooding frog might be the first species brought back from the dead permanently. The first de-extinction happened in 2003, although it lasted all too briefly. Scientists coaxed a clone of an extinct ibex from Spain to birth from a special hybrid goat. But the cloned bucardo bore a third lung and couldn't breathe properly, dying within 10 minutes.
Although this early effort failed, the growing cohort of resurrection projects raises a central question: Does extinction mean forever, anymore? If not, do we have an obligation to bring species back? "If it's clear that we exterminated these species, we not only have a moral obligation to see what we can do about it but a moral imperative to do something if we can," Archer argued. The new science of synthetic biology aims to make it possible for him to fulfill that moral imperative.
Sixth extinction
Humans have killed off many species, both iconic and common. A lighthouse keeper's cat Tibbles—aided by a few feral cats perhaps—caught and killed nearly every single Stephens Island wren just as they were discovered by science in 1900. Hungry sailors ate the Steller's sea cow to death within a century of its discovery. The Xerces Blue butterfly disappeared with the sand dunes from San Francisco in the 1940s as that city swelled. The American chestnut, once the most abundant tree in eastern North America, succumbed to a fungal blight imported from Asia by humans.
"As a human species, we have been amazingly efficient at making things extinct," noted conservation scientist Kate Jones of University College London at the TEDx DeExtinction event.
As the extinction rate swells thanks to habitat loss, over-hunting and human-induced climate change, the world may be on pace to lose half of all species by the end of this century—a reality dubbed the sixth extinction because it would represent the sixth mass die-off of life in Earth's history. Of course, the other five were caused by climatic, planetary or astronomic events.
The de-extinction effort is being led by a group of scientists and others, ranging from synthetic biologist George Church of Harvard Medical School to environmental gadfly Steward Brand of the Long Now Foundation and its Revive & Restore project. They have banded together to see if new genetic tools might enable them to bring back even more species, as Archer is attempting to do with the gastric brooding frog. Their first target is the passenger pigeon, which once was so abundant it darkened the skies of eastern North America.
A similar bid by scientists in South Korea to revive the woolly mammoth—an even more scientifically challenging feat because it has been extinct for thousands of years—may garner the most attention, however. And no need to stop there; extinct human species, like the Neanderthal, could be revived as well, or even sabre-tooth cats—although species that have been extinct for more than a few thousand years are unlikely to be found preserved with enough DNA intact to permit their restoration. (Say goodbye to Jurassic Park.)
As the bucardo example shows, however, de-extinction will be no easy feat. For the bucardo, scientists will not only need to get a female clone to survive, they will also need to find a Y chromosome to make a male bucardo and then stitch that into the cloned DNA. Another approach, championed by Robert Lanza of Advanced Cell Technology, is to forego cloning and instead create stem cells from the ancient DNA. That would then enable Lanza or other scientists to create sperm or egg cells that bear the DNA of endangered or extinct species—and can provide the genetic code to restore or resurrect them.
Going from DNA to a stem cell of some kind, that is then coaxed into becoming a sperm or egg cell, and finally grows into a mammoth, however, is a process still beyond even the most advanced genetic science. "You cannot realistically change one or 10 percent of a genome and have that go to term," Lanza noted in an interview with Scientific American, which is the reason for multiple implantations when attempting to impregnate. But "this is the beginning. It's not going to stop."
Furthermore, as paleogenomicist Beth Shapiro of the University of California, Santa Cruz, reminded the TEDx audience, creating an embryo is just the first step in bringing any extinct species back. There is also the mammoth challenge of restoring the world—or at least the ecosystems—that the elephant relatives inhabited, among other hurdles. And given the perilous plight of still extant elephant species, humanity has yet to show that it can manage the survival, let alone the revival, of a pachyderm.
Keep it cool
Still, there are lessons to be learned from the mammoth, not least the importance of cold. The Arctic "is the best place for the long-term preservation of DNA," Shapiro said. "It's cold and it's been cold for at least the last million years."
Just as mammoth DNA has waited in the Siberian tundra, preserved by constant cold temperatures, the cold of the San Diego's frozen zoo may be the key to ensuring that today's biodiversity makes it through the next few centuries of the Anthropocene intact. This ark, maintained at a steady -197 degrees Celsius, holds the cells of 503 mammals, 170 birds, 70 reptiles and 12 amphibians and fish—out of an estimated 10 million animal, plant, microbe and fungal species on the planet. The collection displays a bias toward charismatic megafauna and thus against the uncharismatic microfauna that keep the planet alive. The cold Svalbard seed vault in Norway performs the same function for crops—species that, despite their importance to us, have dwindled in biodiversity as genetic engineering has created specialized variants that now dominate the landscape.
Some conservationists also pour cold water on the very idea of de-extinction, worrying that it could enable the extinction of yet more species by diverting funds from proven efforts to sustain them, such as protected areas, intensive management of small surviving populations, even advertising campaigns to reduce the consumption of endangered species. We might bring the mammoth back while letting its relatives slip away. "At this moment, brave conservationists are risking their lives to protect forest elephants from armed poachers," noted biologist David Ehrenfeld of Rutgers University at TEDx. "And we're talking in this safe auditorium about bringing back the woolly mammoth?"
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24 Comments
Add CommentThe comment about protecting forest elephants is a non sequiter. There is no reason to ignore one while pursuing the other, especially since (as Ehrenfeld made clear) the two worthy projects would be undertaken by two non-overlapping groups of people. If anything, the desperate difficulty of de-extinction would do *more* to make clear to the public how valuable it is to preserve a diversity of species.
Reply | Report Abuse | Link to thisThe attitude behind the problem is not "let them go extinct, because we can later undo this harm", but is instead: "let them go extinct because I don't really see much value in preserving some stupid tadpole-puking frog". If we see scientists passionately trying to move heaven and earth to make this happen, this can only ignite enthusiasm for species diversity.
One question I don't see addressed here it the effect of the revived species on the existant related species in terms of natural selection. If the ultimate goal is to restore the revived species to nature, would this endanger the survival of animals living today, whether related or not?
Reply | Report Abuse | Link to thisI rather suspect that some of the limited habitat species could be restored with no harm. It would be wonderful to recover the golden toad of Costa Rica. And I suspect that modern conservation ethics would avoid some mistakes of the past. I doubt we'd kill off the passenger pigeon, Carolina parakeet or Steller's sea cow today, even with our far greater numbers.
Reply | Report Abuse | Link to thisIt's a fair point. The concern seems to be that in a zero sum game over the pool of funding for conservation too much might be diverted into "sexy" efforts like de-extinction rather than the patient, hard work of species preservation, like the California condor.
Reply | Report Abuse | Link to thisThe short answer is: no one knows. Some think that, say, restoring the mammoth would help revitalize a landscape that is "missing" them, like the Siberian tundra. But it's at least equally possible that bringing back the passenger pigeon could turn out to be a vector for some avian flu that then decimates other populations. We don't know.
Reply | Report Abuse | Link to thisHear hear! I hope you would be right.
Reply | Report Abuse | Link to thisA species like the North American chestnut that is recently extinct and fits into the current ecosystem may well be worth reviving. And it is not likely to be dangerous. However, a species that has been extinct for many years is much more problematic. Any introductory ecology text has multiple stores like kudzu. A species that was introduced into an environment for a potential benefit, that then out-competes native species and drives them into or towards extinction. Reviving an old species and placing it in an ecosystem that it did not evolve in is a serious issue and needs to be carefully thought out.
Reply | Report Abuse | Link to thisLife evolves to utilize energy niches. Each species has an environmental footprint, that interacts with all other species in the ecology. Time of day, what they eat, where they crap, is all part of the mix.
Reply | Report Abuse | Link to thisReintroducing extinct species is a bit of a ridiculous task in my opinion.
We'll be putting far more into extinction than we'll ever reintroduce.
We've already put the forces in motion to ruin the biosphere for human life.
Few understand or accept this, but imho it's fact.
That's why I have no children, it's the best anyone can do to reduce their lifetime environmental impact.
www.vhemt.org we're vehement.
How lucky we women are to have the option to not have children for whatever reason.
Reply | Report Abuse | Link to thisThe scientific learning possible through de-extinction in the laboratory would be highly valuable. And we might gain access to new drugs that would benefit humankind.
Reply | Report Abuse | Link to thisHowever, releasing de-extincted animals or plants into the wild is a really bad idea.
You ask: "Will We Kill Off Today's Animals If We Revive Extinct Ones?" Are you kidding? Of course we will, in our fathomless zeal to destroy and re-order the earth and its inhabitants to our ignorant satisfaction. While volatile, the earth was in a very stable state, a state of balance altered very slowly by natural forces and evolution, until the past 100 years. A stable state, one welcoming to the survival of the human race, its current inhabitants and the inhabitants we have driven to extinction, in the mistaken belief advanced by mind-boggling hubris, that our ravaging will have no consequences, or even worse the belief that we can improve the earth as we found it (or it found us).
Reply | Report Abuse | Link to thisAs we continue to tamper with the natural order of all things, organic and inorganic, BECAUSE WE CAN (that being the kind of species we are), we ourselves pose an existential threat to our survival.
I am not a luddite. I believe in and have benefited during my life from innovation and progress. I am all for enlightenment but with all our "smarts", we somehow should be smart enough to manifest a little more humility in the exercise of our intelligence and not just barrel ahead as if we were in a friggin amusement park.
Growers of the American Chestnut may find this report of it's demise to be greatly exaggerated:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/American_chestnut
While it has been devastated by the disease, there are still healthy groves and progress is being made in restoring them.
Not for long. That choice will be gone with 2 decades if not sooner.
Reply | Report Abuse | Link to thisphil5Bob, I couldn't agree with you more. Human innovation and the dogged refusal to accept things "as they are" is the force that propelled Salk, Pasteur, Mendel--hell, even Galen (as backward as he was). Such a fine line between audacity and recklessness, though. Your amusement park analogy is quite on point.
Reply | Report Abuse | Link to thisAs someone else has commented, the American chestnut is not extinct. It persists as infected stump sprouts throughout its original range, and there are a few isolated healthy groves at the far limits of its range to which the blight hasn't spread. The resprouting stumps are a common sight in New England woods.
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Reply | Report Abuse | Link to this~
Why don't we consider reviving Intelligent humans?
Those seem to have gone extinct recently.
~
Just look at New Zealand, if you want to see what happens when species are introduced where they don't belong.
Reply | Report Abuse | Link to thisPossums, rabbits, feral cats, rats, mice etc don't belong here.
And the most destructive of all, humans!
Isn't it way too obvious that the issue here is not extinction, it is over-population of our species; Domination rather than stewardship?
Reply | Report Abuse | Link to thisWe do not know the long term effects or the unforeseen consequences of this proposed work.
Reply | Report Abuse | Link to thisI feel that although it would be a wonderful learning opportunity - I should be left well alone!
Sorry I meant It should be left well alone!
Reply | Report Abuse | Link to thisNot to worry. I think more living species would be better, and we're much better at exterminating them than (re)creating them, though too good at "recreating" individuals of our own species.
Reply | Report Abuse | Link to thisI actually think de-extinction is a wrong thing. The process of evolution does not account for this kind of stuff. If we let the extinct species remain extinct, then future species will have been able to adapt traits in which the next time there is anything of mass human impact, they will be able to adapt to it. However, if we try to de-extinct certain species, those species will likely soon die off. Again, there was a reason why they were extinct in the first place- they couldn't survive the conditions.
Reply | Report Abuse | Link to thisAlso, let's take some common sense. Who in the world would want mega-large animals the size of dinos roaming around the earth?
When the skies were darkened by massive flocks of passenger pigeons, what happened to those on the ground underneath them? Has anyone examined the effects of extremely large quantities of pigeon feces on the health of those who experience it? Every time I see a reference to this species, it's always in romanticized terms; oh, how wonderful it must have been. How would the reality have been? We don't ask that very often.
Reply | Report Abuse | Link to thisThe only de-extinctification I know of is Tiger Woods career. Thot Elan killed all that.
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