Genetic researchers may have resolved a long-standing dispute by proving there are two species of African elephant.Savannah and forest elephants have been separated for at least three million years, they say, and are as distinct from each other as Asian elephants are from the extinct woolly mammoth. The researchers also made what they say are the first sequences of nuclear DNA from the extinct American mastodon. > "The divergence of the two species took place around the time of the divergence of the Asian elephant and woolly mammoths," said Michi Hofreiter, a specialist in ancient DNA at the UK's York...