No fabled creature of the Pleistocene Era has a more powerful hold on the imagination than does the woolly mammoth. Cave paintings of the giant beasts hint at the profound role they played in early human culture-our Ice Age ancestors built igloo-shaped huts out of mammoth bones and even feasted on mammoth tongues. Eager to uncover more clues to this mystical prehistoric age, explorers since the time of Peter the Great have scoured Siberia for mammoth...