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  • Now, extinction is a different kind of death.

  • It's bigger.

  • We didn't really realize that until 1914,

  • when the last passenger pigeon, a female named Martha,

  • died at the Cincinnati zoo.

  • This had been the most abundant bird in the world

  • that'd been in North America for six million years.

  • Suddenly it wasn't here at all.

  • Flocks that were a mile wide and 400 miles long

  • used to darken the sun.

  • Aldo Leopold said this was a biological storm,

  • a feathered tempest.

  • And indeed it was a keystone species

  • that enriched the entire eastern deciduous forest,

  • from the Mississippi to the Atlantic,

  • from Canada down to the Gulf.

  • But it went from five billion birds to zero in just a couple decades.

  • What happened?

  • Well, commercial hunting happened.

  • These birds were hunted for meat that was sold by the ton,

  • and it was easy to do because when those big flocks

  • came down to the ground, they were so dense

  • that hundreds of hunters and netters could show up

  • and slaughter them by the tens of thousands.

  • It was the cheapest source of protein in America.

  • By the end of the century, there was nothing left

  • but these beautiful skins in museum specimen drawers.

  • There's an upside to the story.

  • This made people realize that the same thing

  • was about to happen to the American bison,

  • and so these birds saved the buffalos.

  • But a lot of other animals weren't saved.

  • The Carolina parakeet was a parrot that lit up backyards everywhere.

  • It was hunted to death for its feathers.

  • There was a bird that people liked on the East Coast called the heath hen.

  • It was loved. They tried to protect it. It died anyway.

  • A local newspaper spelled out, "There is no survivor,

  • there is no future, there is no life to be recreated in this form ever again."

  • There's a sense of deep tragedy that goes with these things,

  • and it happened to lots of birds that people loved.

  • It happened to lots of mammals.

  • Another keystone species is a famous animal

  • called the European aurochs.

  • There was sort of a movie made about it recently.

  • And the aurochs was like the bison.

  • This was an animal that basically kept the forest

  • mixed with grasslands across the entire Europe and Asian continent,

  • from Spain to Korea.

  • The documentation of this animal goes back

  • to the Lascaux cave paintings.

  • The extinctions still go on.

  • There's an ibex in Spain called the bucardo.

  • It went extinct in 2000.

  • There was a marvelous animal, a marsupial wolf

  • called the thylacine in Tasmania, south of Australia,

  • called the Tasmanian tiger.

  • It was hunted until there were just a few left to die in zoos.

  • A little bit of film was shot.

  • Sorrow, anger, mourning.

  • Don't mourn. Organize.

  • What if you could find out that, using the DNA in museum specimens,

  • fossils maybe up to 200,000 years old

  • could be used to bring species back,

  • what would you do? Where would you start?

  • Well, you'd start by finding out if the biotech is really there.

  • I started with my wife, Ryan Phelan,

  • who ran a biotech business called DNA Direct,

  • and through her, one of her colleagues, George Church,

  • one of the leading genetic engineers

  • who turned out to be also obsessed with passenger pigeons

  • and a lot of confidence

  • that methodologies he was working on

  • might actually do the deed.

  • So he and Ryan organized and hosted a meeting

  • at the Wyss Institute in Harvard bringing together

  • specialists on passenger pigeons, conservation ornithologists, bioethicists,

  • and fortunately passenger pigeon DNA had already been sequenced

  • by a molecular biologist named Beth Shapiro.

  • All she needed from those specimens at the Smithsonian

  • was a little bit of toe pad tissue,

  • because down in there is what is called ancient DNA.

  • It's DNA which is pretty badly fragmented,

  • but with good techniques now, you can basically reassemble the whole genome.

  • Then the question is, can you reassemble,

  • with that genome, the whole bird?

  • George Church thinks you can.

  • So in his book, "Regenesis," which I recommend,

  • he has a chapter on the science of bringing back extinct species,

  • and he has a machine called

  • the Multiplex Automated Genome Engineering machine.

  • It's kind of like an evolution machine.

  • You try combinations of genes that you write

  • at the cell level and then in organs on a chip,

  • and the ones that win, that you can then put

  • into a living organism. It'll work.

  • The precision of this, one of George's famous unreadable slides,

  • nevertheless points out that there's a level of precision here

  • right down to the individual base pair.

  • The passenger pigeon has 1.3 billion base pairs in its genome.

  • So what you're getting is the capability now

  • of replacing one gene with another variation of that gene.

  • It's called an allele.

  • Well that's what happens in normal hybridization anyway.

  • So this is a form of synthetic hybridization of the genome

  • of an extinct species

  • with the genome of its closest living relative.

  • Now along the way, George points out that

  • his technology, the technology of synthetic biology,

  • is currently accelerating at four times the rate of Moore's Law.

  • It's been doing that since 2005, and it's likely to continue.

  • Okay, the closest living relative of the passenger pigeon

  • is the band-tailed pigeon. They're abundant. There's some around here.

  • Genetically, the band-tailed pigeon already is

  • mostly living passenger pigeon.

  • There's just some bits that are band-tailed pigeon.

  • If you replace those bits with passenger pigeon bits,

  • you've got the extinct bird back, cooing at you.

  • Now, there's work to do.

  • You have to figure out exactly what genes matter.

  • So there's genes for the short tail in the band-tailed pigeon,

  • genes for the long tail in the passenger pigeon,

  • and so on with the red eye, peach-colored breast, flocking, and so on.

  • Add them all up and the result won't be perfect.

  • But it should be be perfect enough,

  • because nature doesn't do perfect either.

  • So this meeting in Boston led to three things.

  • First off, Ryan and I decided to create a nonprofit

  • called Revive and Restore that would push de-extinction generally

  • and try to have it go in a responsible way,

  • and we would push ahead with the passenger pigeon.

  • Another direct result was a young grad student named Ben Novak,

  • who had been obsessed with passenger pigeons since he was 14

  • and had also learned how to work with ancient DNA,

  • himself sequenced the passenger pigeon,

  • using money from his family and friends.

  • We hired him full-time.

  • Now, this photograph I took of him last year at the Smithsonian,

  • he's looking down at Martha,

  • the last passenger pigeon alive.

  • So if he's successful, she won't be the last.

  • The third result of the Boston meeting was the realization

  • that there are scientists all over the world

  • working on various forms of de-extinction,

  • but they'd never met each other.

  • And National Geographic got interested

  • because National Geographic has the theory that

  • the last century, discovery was basically finding things,

  • and in this century, discovery is basically making things.

  • De-extinction falls in that category.

  • So they hosted and funded this meeting. And 35 scientists,

  • they were conservation biologists and molecular biologists,

  • basically meeting to see if they had work to do together.

  • Some of these conservation biologists are pretty radical.

  • There's three of them who are not just re-creating ancient species,

  • they're recreating extinct ecosystems

  • in northern Siberia, in the Netherlands, and in Hawaii.

  • Henri, from the Netherlands,

  • with a Dutch last name I won't try to pronounce,

  • is working on the aurochs.

  • The aurochs is the ancestor of all domestic cattle,

  • and so basically its genome is alive, it's just unevenly distributed.

  • So what they're doing is working with seven breeds

  • of primitive, hardy-looking cattle like that Maremmana primitivo on the top there

  • to rebuild, over time, with selective back-breeding,

  • the aurochs.

  • Now, re-wilding is moving faster in Korea

  • than it is in America,

  • and so the plan is, with these re-wilded areas all over Europe,

  • they will introduce the aurochs to do its old job,

  • its old ecological role,

  • of clearing the somewhat barren, closed-canopy forest

  • so that it has these biodiverse meadows in it.

  • Another amazing story

  • came from Alberto Fernández-Arias.

  • Alberto worked with the bucardo in Spain.

  • The last bucardo was a female named Celia

  • who was still alive, but then they captured her,

  • they got a little bit of tissue from her ear,

  • they cryopreserved it in liquid nitrogen,

  • released her back into the wild,

  • but a few months later, she was found dead under a fallen tree.

  • They took the DNA from that ear,

  • they planted it as a cloned egg in a goat,

  • the pregnancy came to term,

  • and a live baby bucardo was born.

  • It was the first de-extinction in history.

  • (Applause)

  • It was short-lived.

  • Sometimes interspecies clones have respiration problems.

  • This one had a malformed lung and died after 10 minutes,

  • but Alberto was confident that

  • cloning has moved along well since then,

  • and this will move ahead, and eventually

  • there will be a population of bucardos

  • back in the mountains in northern Spain.

  • Cryopreservation pioneer of great depth is Oliver Ryder.

  • At the San Diego zoo, his frozen zoo

  • has collected the tissues from over 1,000 species

  • over the last 35 years.

  • Now, when it's frozen that deep,

  • minus 196 degrees Celsius,

  • the cells are intact and the DNA is intact.

  • They're basically viable cells,

  • so someone like Bob Lanza at Advanced Cell Technology

  • took some of that tissue from an endangered animal

  • called the Javan banteng, put it in a cow,

  • the cow went to term, and what was born

  • was a live, healthy baby Javan banteng,

  • who thrived and is still alive.

  • The most exciting thing for Bob Lanza

  • is the ability now to take any kind of cell

  • with induced pluripotent stem cells

  • and turn it into germ cells, like sperm and eggs.

  • So now we go to Mike McGrew

  • who is a scientist at Roslin Institute in Scotland,

  • and Mike's doing miracles with birds.

  • So he'll take, say, falcon skin cells, fibroblast,

  • turn it into induced pluripotent stem cells.

  • Since it's so pluripotent, it can become germ plasm.

  • He then has a way to put the germ plasm

  • into the embryo of a chicken egg

  • so that that chicken will have, basically,

  • the gonads of a falcon.

  • You get a male and a female each of those,

  • and out of them comes falcons.

  • (Laughter)

  • Real falcons out of slightly doctored chickens.

  • Ben Novak was the youngest scientist at the meeting.

  • He showed how all of this can be put together.

  • The sequence of events: he'll put together the genomes

  • of the band-tailed pigeon and the passenger pigeon,

  • he'll take the techniques of George Church

  • and get passenger pigeon DNA,

  • the techniques of Robert Lanza and Michael McGrew,

  • get that DNA into chicken gonads,

  • and out of the chicken gonads get passenger pigeon eggs, squabs,

  • and now you're getting a population of passenger pigeons.

  • It does raise the question of,

  • they're not going to have passenger pigeon parents

  • to teach them how to be a passenger pigeon.

  • So what do you do about that?

  • Well birds are pretty hard-wired, as it happens,

  • so most of that is already in their DNA,

  • but to supplement it, part of Ben's idea

  • is to use homing pigeons

  • to help train the young passenger pigeons how to flock

  • and how to find their way to their old nesting grounds

  • and feeding grounds.

  • There were some conservationists,