Engineer Plans to Bring Back the Long-Extinct Woolly Mammoth

By splicing genes, George Church hopes to revive the woolly mammoth, or at least create a version of the modern elephant that really likes the cold.

Harvard geneticist George Church goes face to face with a woolly mammoth of the computer-generated variety in "How to Clone a Woolly Mammoth," a documentary airing on the Smithsonian Channel on Nov. 29.Renegade Pictures