TOPICS > Science > Extinction Week

Potential to revive extinct animals raises ethical questions

April 22, 2014 at 6:21 PM EDT
Researchers are working to bring back extinct animals like the woolly mammoth and passenger pigeon, operating under the belief that reviving such species could restore vanishing habitats. But many biologists suggest these efforts should focus on endangered, rather than extinct, species. Gabriela Quiros and Thuy Vu of KQED have the story.

JUDY WOODRUFF: And now, a story on this Earth Day that seems lifted from science fiction.

Researchers and entrepreneurs, many in California, are trying to bring back extinct species. Some scientists believe it’s a way to correct past mistakes and even help endangered animals.

But just because scientists might be able to do this, are they crossing a line they shouldn’t?

Our colleagues at public TV station KQED in San Francisco explored that question in this story produced by Gabriela Quiros and narrated by Thuy Vu.

JULIANNE MOORE, Actress: I will be right back.

JEFF GOLDBLUM, Actor: Sarah, no, no.

THUY VU, KQED: The cloned dinosaurs of the “Jurassic Park” movies captured viewers’ imaginations. But 65 million years after their extinction, there’s no chance scientists can bring dinosaurs back, says University of California, Santa Cruz, biologist Beth Shapiro.

BETH SHAPIRO, University of California, Santa Cruz: “Jurassic Park” is a fantasy and always will be. Dinosaurs are way too old to think that we’re going to be able to recover genetic material.

THUY VU: Instead, scientists are focusing on species that went extinct more recently, for which DNA still exists.

Researchers have already revived one extinct animal. The last of a type of mountain goat was cloned in Spain in 2003. But the clone only lived a few minutes. Here in the U.S., George Church, from Harvard Medical School, is engineering elephant cells with thicker hair and a fatty layer, to make them more like woolly mammoth.

His hope is that these new mammoths could help keep the Arctic from melting. Scientists believe that grazing by herbivores like mammoths strengthened the grass that grew on top of the permafrost and protected it from the sun.

GEORGE CHURCH, Harvard Medical School: The mammoths may have had a big role in maintaining the grass that stabilized the ice, which contains more carbon in it, as in global warming carbon, than all the rain forests put together times two.

THUY VU: To turn elephants into woolly mammoths, Church is using a new tool that allows him to insert genes into the elephant genome.

GEORGE CHURCH: It’s like very precise scissors that allow you to cut and splice with unprecedented accuracy and ease of use.

THUY VU: Despite the ethical question raised by the use of elephants, which are endangered, scientists are already interested in using the technology to bring back other extinct animals. One of them is the passenger pigeon.

BEN NOVAK, Revive & Restore: In the early 1800s, there were five billion of these birds just in the United States. Within the span of about 50 years, they go extinct.

THUY VU: At U.C. Santa Cruz, 27-year-old Ben Novak is working to de-extinct what was once the most abundant bird in the world.

BEN NOVAK: It opens the door to this brand-new future of conservation, in which we can finally shift gears from thinking that we’re losing life on this planet to the fact that we are actually gaining it back.

THUY VU: Not to be confused with domesticated carrier pigeons, passenger pigeons were wild birds that migrated through the Eastern and Central U.S. and Canada.

BEN NOVAK: You had these giant flocks of birds so dense that, with a single shot, you could take down dozens of them.

THUY VU: Shipped by the trainloads to feed hungry cities, the passenger pigeon went extinct in 1914, when the last one died at the Cincinnati Zoo. Novak plans to genetically engineer its closest relative, the band-tailed pigeon. He would insert genes he obtained from passenger pigeon museum specimens.

This is a painstaking process, as DNA is degraded and it’s hard to identify what genes do what. Novak would like to replace band-tailed pigeons’ square tails with the long tail and swift wings that allowed passenger pigeons to fly at 60 miles per hour.

WOMAN: Hey, Ben.


WOMAN: How are you doing?

THUY VU: Ryan Phelan and Stewart Brand’s nonprofit, Revive & Restore, in Sausalito, California, is funding Novak’s work.

STEWART BRAND, Co-Founder, Revive & Restore: Have you seen this cool thing?

BEN NOVAK: Well, according to Amazon, it’s not published yet.

THUY VU: Brand is best known for his Whole Earth Catalog. Started in 1968, it encouraged readers to live in tune with nature. Today, Brand hopes to excite a new generation through de-extinction.

STEWART BRAND: Do you want extinct species back? Do you want extinct species back?


STEWART BRAND: That a huge population could just go to zero, that was the beginning of taking extinction seriously. And so to go back to that original mistake or crime, and try to undo it, there might be some redemption in that.

JIM PATTON, Museum of Vertebrate Zoology, University of California, Berkeley: That, to me, is the wrong attitude.

THUY VU: Biologist Jim Patton, at the University of California, Berkeley, doesn’t share Brand’s enthusiasm.

JIM PATTON: We’re lost, unless we realize that we’re just a part of this intricate web. And we ought to bring species back if they can help maintain that web, but not because it makes us feel better and sleep better at night.

THUY VU: Phelan and Brand estimate it will take $5 million to $50 million to bring back the passenger pigeon.

STEWART BRAND: Where the money tends to be coming in is from people in high-tech. They like being on cutting edges, and this is one.

THUY VU: Brand believes passenger pigeons could help restore the East Coast’s forests by spreading seeds around. But the pigeons could end up in conflict with humans once again, especially if they were listed under the Endangered Species Act.

BETH SHAPIRO: If it’s an endangered species, then, all of a sudden, all of the forest habitat where it goes into will be off-limits to hunting and hiking and biking.

JIM PATTON: Will the people in the East Coast be willing to put up with thousands of pigeons defecating all over everything?

THUY VU: And Brand recognizes that much of the science is still unknown.

STEWART BRAND: If you turn a band-tailed pigeon into a passenger pigeon, is it really a passenger pigeon, or is it just some weird kind of chimera or hybrid or what? And the answer is, we don’t know yet. And you won’t really know until you try it.

THUY VU: The enterprise of reviving disappeared species is driven, at least in part, by the increasing extinction rate that scientists have observed in the past 500 years.

At San Francisco’s California Academy of Sciences, biologist Jack Dumbacher guards the remnants of extinct animals.

JACK DUMBACHER, California Academy of Sciences: There are actually only two keys to this case. I have one and the collection manager has the other.

Humans are the reason why species are going extinct at a higher rate. Human population sizes are so big that we’re having a huge impact, destroying habitat and converting habitat from its natural form into agriculture, to cities, to other things that we use.

THUY VU: Climate change is making things worse, by turning the oceans inhospitable to coral reefs, for example. Some scientists estimate that if temperatures continue to climb, they could contribute to the disappearance of half the world’s species.

JACK DUMBACHER: If you have got some ecosystem that we know is collapsing because we have lost some key ecosystem component, and we can de-extinct it, why wouldn’t we do that?

THUY VU: But many biologists believe that efforts should focus on endangered, rather than extinct, species.

JIM PATTON: It comes down hugely to priorities.

If we have these technologies and these technologies can be brought to bear to help preserve what is already here, that’s where I would put my resources.

THUY VU: Scientists say the need for these tools is great. At the San Diego Zoo’s Safari Park, in Escondido, California, Nola and Angi are two of only seven northern white rhinos left in the world.

Poached for their horns, the rhinos are believed to have disappeared in the wild around 2006. At 40, the park’s two rhinos have ended their baby-making years, and it’s also unlikely that the other five will reproduce either, says zoo geneticist Oliver Ryder.

OLIVER RYDER, Director of Genetics, San Diego Zoo Institute for Conservation Research: Without some extraordinary intervention, northern white rhinos are doomed.

THUY VU: Those extraordinary measures begin with rhino cells stored at minus-250 degrees at the San Diego Zoo’s Frozen Zoo. Scientists have collected cells from 12 northern white rhinos. Using stem cell techniques and in vitro fertilization, they hope to increase the rhino population and its genetic diversity.

The frozen zoo holds the cells of 1,000 different species, many of them endangered. With new technologies, these cells could one day become a lifeline.

JUDY WOODRUFF: And there’s more on our Web site. Watch KQED’s full half-hour documentary, “Reawakening Extinct Species.”  That’s part of NewsHour’s Extinction Week online.