theodp writes: Slashdot's been following de-extinction efforts for a good 15 years. Now, in The Mammoth Cometh, this week's NY Times Magazine cover story, Nathaniel Rich writes that "bringing extinct animals back to life is really happening — and it’s going to be very, very cool. Unless it ends up being very, very bad." Among the "genetic rescues" being pursued by The Long Now Foundation's Revive & Restore project is The Great Passenger Pigeon Comeback. And returning a flock of passenger pigeons to the planet is just the tip of the iceberg. "We're bringing back the mammoth to restore the steppe in the Arctic," says Stewart Brand. "One or two mammoths is not a success. 100,000 mammoths is a success." De-extinction, while no doubt thrilling ("It would certainly be cool to see a living saber-toothed cat,” Stanford's Hank Greely and Jacob Sherkow argued in Science), is disturbing to many conservation biologists who question the logic of bringing back an animal whose native habitat has disappeared, worry about disease, and are concerned that money may be diverted from other conservation efforts.