 It's a question that paleontologists have been trying to answer for years. Were the last woolly mammoths wiped out by a sudden mysterious event, or did their numbers just dwindle? The last group is known to have lived on an island off the coast of Siberia. DNA tests carried out on their remains by teams from the Swedish Museum of Natural History and Stockholm University found evidence of inbreeding, but also that their numbers were stable until the end. This challenges the theory that they died out because they were inbred.