AS DRAMATIC AS it may have been, the defrosting still didn't bode well for the prospects of cloning—the lurking, thrilling idea that had drawn the huge television audiences (and me) in the first place. Since the heady first days after the mammoth's helicopter flight, the prospect of a reborn race of woollies someday emerging from the ice cave has receded further and further into the distance.

Ever since the movie Jurassic Park and the 1996 birth of Dolly the sheep, the idea of cloning prehistoric animals has hovered around the collective consciousness of both Hollywood and science. A few years before Buigues arrived on the scene, a Japanese expedition came to the Taimyr to search (without success) for a specimen from which they might clone a mammoth. Buigues and one of his scientific collaborators, a University of Northern Arizona paleontologist named Larry Agenbroad, originally hailed their specimen as a possible source of viable DNA—or even sperm—that would permit cloning. But almost immediately other scientists (including MacPhee, who hadn't yet met Buigues) stepped forward to denounce the notion that a mammoth could ever be cloned—or that even if it could be, it ought to be.

The biggest practical difficulty, MacPhee says, is that DNA's fragile strands deteriorate quickly, and no foreseeable technology can repair it. And besides, he adds, "Who's going to want to have a herd of mammoths lumbering across the countryside? You'd end up with one or two animals cloned, as a kind of freak show, and then everyone would lose interest."

Even so, the week I left for Khatanga, a New York Times headline announced the planned cloning of an extinct animal: not a mammoth, but a breed of Spanish mountain goat, the last of which had died a few months earlier. The scientists were given a good chance of success.

Agenbroad still believes that the Khatanga mammoth, despite its condition, may yet yield cloneable DNA. Moreover, he has few qualms about the prospect. "I live in the West, where we humans, the hunters and ranchers, eliminated huge numbers of grizzly bears and wolves. Now the federal government is bringing them back. Is that so different?" After Agenbroad spoke in favor of cloning on the Discovery Channel's first broadcast, he received a barrage of hate e-mail. But he continues unapologetically to envision a not-too-distant future in which mammoths range like bison across the grasslands of Asia and North America—and points out that the director of Pleistocene Park, a nature reserve in Siberia, has announced that he's ready to provide a loving home to a cloned mammoth, whenever the first one happens to be born.

If the birth of that 21st-century mammoth remains out of reach, solid information about the disappearance of the Pleistocene mammoths is equally elusive. By around 8,000 b.c. they were all gone, save a remnant population that held out for a few thousand years longer on a small Siberian island, living and dying while the pharaohs ruled Egypt. Scientists are sharply divided over what caused the extinction. Their three leading hypotheses, Agenbroad told me, can be summed up as "overkill, overchill, and overill." The debate is about far more than paleontology. It's about the past and future of humanity's relationship with the natural world.

MacPhee is the illness theory's leading proponent. It's nearly impossible that humans hunted mammoths to extinction, he told me as we sat one morning in his room at Khatanga's lone hotel, drinking cognac. "It contradicts everything we know about how extinctions happen," he said. "Look at whales. For centuries you had enormous whale fleets armed with the most sophisticated technology of their time, manned by experts working morning, noon, and night to kill more whales. And of course they caused enormous destruction. But how many whale species have gone extinct in the past 500 years? Zero." The most likely culprit for the mammoths' demise, MacPhee believes, was some sort of global epidemic, a "hyperdisease" possibly borne by humans. This would explain why the animals vanished from the New World shortly after the ancestors of native Americans arrived.

Scientists of the "overchill" school believe that climate changes after the last Ice Age destroyed habitat and vegetation that the mammoths needed to survive. But the theory that most captures the public's imagination is the overkill hypothesis. Agenbroad has spent decades excavating mammoth remains around the western United States. "You can't work on a mammoth-kill site without getting the idea you're looking at a magnificent animal that has been butchered by humans," he says. "Eleven thousand years ago, man and mammoths were mixing it up, no doubt about it. Especially in America, where they'd never been hunted before and weren't used to this funny-looking predator. It was like shooting ducks in a bathtub." Agenbroad believes that a sudden burst in human population, along with wickedly efficient new tools such as improved spearpoints, drove mammoths over the brink.

In other words, humans were doing then exactly what their descendants, according to environmentalists, are doing now: overbreeding and trashing nature with technology. MacPhee scoffs at what he sees as the all-too-convenient sentimental appeal of this idea: "It fits with the worldview that everything wrong with the planet has to do with what humans have done." Furthermore, he adds, the theory would be far less appealing if woolly mammoths didn't make such cute, guilt-inducing victims: not just elephants, but shaggy, plush-toy versions of elephants—a species that could've been invented by Hasbro.

Still, Agenbroad takes his argument one step further. If the mammoth was one of the first species that human technology sent into oblivion, we can atone for it by making it one of the first species that human technology will resurrect. "We almost owe it to 'em," he says.