Gaea Pangaea (gaeapangaea) wrote,
Gaea Pangaea

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this sounds like a terrible idea all around, although i can appreciate the theory behind it.

Jennifer Viegas, Discovery News

July 11, 2006 — Scientists are questioning a plan to "re-wild" parts of North America with large mammals, mostly from Africa, that are close counterparts to extinct Pleistocene-period animals that once roamed the Great Plains.

Studies suggest humans contributed to the extinctions during the Pleistocene,which spanned 1.8 million to about 10,000 years ago. The losses left critical gaps in ecosystems that proponents of the plan hope to fill.

The proposal, published in Nature last year, suggested, for example, that free-ranging African cheetahs, feral horses, wild asses, Bactrian camels, lions and Asian and African elephants could be brought to large tracts of private western North American land.

"We are not advocating backing up a van and letting elephants and cheetahs out into the landscape," said Josh Donlan, a doctoral candidate in the Department of Ecology and Evolutionary Biology at Cornell University."All of this would be science-driven."

Critics, however, believe we cannot fully revisit the past.

"When the Pleistocene megafauna went extinct more than 10,000 years ago,their ecosystems nonetheless continued to change and evolve without them," said Dustin Rubenstein, lead author of an upcoming Biological Conservation paper addressing the proposal.

Rubenstein, are searcher in the Department of Neurobiology and Behavior at Cornell,added, "We do not have the luxury of being able to start over and recreate the bygone habits and associated megafauna. We can never return North American ecosystems to the way that they were in the Pleistocene, especially since we are not sure what they really were like back then."

One of the goals of the Pleistocene rewilding concept is to restore the evolutionary potential of remaining North American animals. For example, pronghorns probably evolved the ability to run 60 miles per hour after four million years of being hunted by the now extinct American cheetah.

Donlan and his group say introducing free-ranging African cheetahs back to the Southwest could restore such interactions between pronghorns and cheetahs.

Rubenstein and his team believe that would be a mistake because the puma is actually more genetically similar to the long-extinct American cheetah.

"It is impossible to restore the evolutionary potential of extinct species,although it may be possible to help maintain the evolutionary potentialof some extant species," Rubenstein told Discovery News.

"For instance, reintroducing extant native predators like mountain lions and wolves to western ecosystems could, in theory, help maintain the evolutionary potential of existing prey species like big horn sheep and pronghorn antelope."

Pleistocene rewilding, in fact, may be disastrous, according to Rubenstein’s group. At best, it would not work, and many of the introduced animals could perish, they believe. At worst, they argue it could "irreparably disrupt current ecosystems and species assemblages."

Another goal of the Pleistocene plan is to help prevent the extinction of existing species by creating new and potentially better-protected populations in North America.

But,since conservation resources are scarce, Rubenstein thinks money and effort would be better spent on preserving native North American animals and their indigenous habitats, and on reintroducing species to places in their historical ranges from which they were only recently wiped out.

"If people are given incentives not to destroyanimals, plants and their local habitats, they become partners in preserving them," he said.
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