Bring back the Shasta ground sloth
Bringing extinct animals back to life is big news this week. Not because there’ve been any particular recent breakthroughs, but because the upcoming issue of National Geographic features the topic as a cover story, and is hosting a related TEDx meeting this Friday in Washington D.C. that’s also sponsored by Stewart Brand’s Long Now Foundation. There’s a Twitter hashtag for the meetup, National Geographic has set up a portal page for the topic (credit Brian Switek for that labor), and the event is driving a lot of traffic to the Long Now site — which is worth checking out, especially its FAQ and its list of criteria for choosing extinct animals to bring back.
But I see no mention of bringing back the extinct animal we actually really need.
Here’s a teaser for the conference via NatGeo:
Bringing back extinct species is a controversial topic, and for a number of good reasons. Once a species goes extinct the relationships individuals of that species had with other species also go extinct, and the ecosystems in which the vanished species once lived change. Sometimes that change is radical. Long Now points out the extinction of the Mammoth Steppe environment that went along with the extinction of the mammoth, as boreal forests grew up without elephants to trample them.
Sometimes the change might be barely noticeable. If a particular species of bee and a particular species of annual plant have an exclusive pollination relationship, one of them going extinct might cause the other species to die out as well, but with little overall effect on the ecosystem that surrounds them, with local animals having one less flavor of bug or plant to eat but otherwise carrying on unaffected. Regardless, the ecosystems an extinct species might have lived in generally don’t sit around being stable once one of their components is gone. They move in a new direction and become, to extents major or minor, new ecosystems. No one’s really talking about reviving vanished species so that we can keep them in zoos or research labs forever: eventually, we’ll be considering whether to release them. But where do we release them? North America has had 8-12,000 years to adapt to the loss of its megafauna: reintroducing the woolly mammoth into its former geographic haunts could be seen as releasing a potentially destructive invasive species into a habitat that has long since moved on. Far from helping heal ancient damage, such a reintroduction might well cause even more new damage.
Another complicating factor is that organisms, as my co-blogger here has pointed out on several occasions, are more than their genome. This is especially true of some animals. The larger a brain an animal has, the more likely it is to have something like culture. This became important when the California condor went extinct in the wild. Pre-breeding-program California condors taught their young how to behave in the wild — how to approach food, how to avoid danger, things like that. Condor culture was passed down from generation to generation. When condor biologists captured the last wild condors in the mid-1980s to enlist them into the so-far successful captive breeding and reintroduction program, they had to play close attention to that condor culture. They’ve done probably as good a job of maintaining that culture as they can, feeding chicks with condor puppets and such, but there are inevitable changes to that culture as a result of human interference.
If the extinct Teratornis merriami had a culture anything like the condor’s, are we really reviving the teratorn when we clone it from some old DNA and hatch it under, say, a condor host mother? Or are we really making a zombie Teratornis that possesses the physiognomy of its extinct kin but is otherwise as blank a slate as its genome allows?
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