Look, over here! Hair!" shouts one of the sperm hunters, pointing to a frayed brown tangle protruding from a cliff along the Kolyma River in Siberia. The young man tugs gently at the strands, in the hope that they're attached to a hulk that long ago lay down for the last time in this Ice Age sediment.
Could this, finally, be the hair of a woolly mammoth, its frozen body, and more important, its genitalia, locked inside the crumbling black cliff? Could this be the first step in a bizarre quest led by Japanese biologists to inseminate an Asian elephant with woolly mammoth sperm and selectively breed a fabled prehistoric creature that became extinct thousands of years ago? “I know it sounds unbelievable,” says Kazufumi Goto, “but no science can deny our idea.”
Zimov turns the hair in his hands, rubs it between his fingers and thumb, then poisons the air with his words: “Steppe bison.” He yanks out the rest of the clump to reveal only more loess, no skin or meat.
Many scientists are skeptical of Goto prospects of resurrecting even one woolly mammoth, but few dismiss the plan out of hand—a remarkable sign of how far reproductive technologies have come in only a few years. It’s not the technology that’s stopping Goto, it’s simply a matter of finding a well-preserved woolly mammoth. “The leap of faith is finding the viable sperm or oocytes [cells that become eggs],” says John Critser, scientific director of the Cryobiology Research Institute in Indianapolis. Critser, who has transplanted elephant ovarian tissue into mice and gotten the mice to produce elephant eggs, says that producing an embryo “is not so far-fetched.”
