The pronghorn antelope is North America’s speediest animal, capable of running 60 miles per hour — but why? Its predators don’t run nearly that fast, so why would the pronghorn evolve such a capability?The answer is probably the cheetah. We think of cheetahs as African, but America had its own cheetahs, along with elephants, lions, camels and wild horses. Since cheetahs can run 60 or 70 mph for short bursts, and enjoy antelope steak, the pronghorns adapted.Now comes one of the craziest — and appealing — ideas in the biological world: reintroducing species to the Americas. Eventually, this could allow Americans to go on camera safaris and see scenes that humans haven’t witnessed on this continent since about 11,000 BC.The genesis for this idea is the realisation that Native Americans were not the fine ecological stewards we imagine. In the Americas, hunters began using effective spears about 13,000 years ago, and in only about four centuries nearly three-quarters of the large animal species had disappeared. Something like that also happened in Australia. So today we think of lions as African, but similar lions were once integral to the ecosystem of North America. So were elephant-like creatures, along with ancient wild horses and the camelops — a Bactrian camel with an American accent.So in a commentary in Nature in August, a handful of scientists led by Josh Donlan of Cornell University suggested a “Pleistocene re-wilding” — the introduction of species from elsewhere that would closely resemble those in the ecosystem of the Pleistocene era, from about 1.65 million years ago until about 10,000 years ago.The proposal provoked gasps of horror, some from Americans who did not wish to look out their back window and see a cheetah devour a camel — or, worse, their child. There’s been such a furor about reintroducing wolves in Yellowstone that I doubt this column will go over well with Montana and Wyoming ranchers.But the idea is not for a Jurassic Park. Things would start slowly with less threatening creatures like the Bolson tortoise, which can weigh 100 pounds. It is now found only in Mexico but was once common in the US.The next step would be to find a 200,000-acre ranch in the Southwest that saw an economic opportunity in working with scientists to recreate a Pleistocene ecosystem and then charging tourists to come and gawk. And, yes, such a game reserve would have a strong perimeter fence.Something similar is being tried in Siberia. As the journal Science recounted in May, biologists in the Russian region of Yakutia are trying to create a Pleistocene Park by reintroducing species similar to the ones that humans killed off there long ago.“Right now when people think of conservation, 1492 is the de facto benchmark,” Donlan said. But he noted that if we really wanted to recover part of the wilderness that existed before humans helped muck up the ecosystem, we might want to go back to what is a heartbeat away in cosmic time: say, 13,000 years.—The New York Times
