Forest elephants in Africa have been confirmed as a different species from the larger savanna elephant seen here. Scientists believe the savanna elephant is as different from the forest elephant as Asian elephants are from woolly mammoths. The two African species diverged about two million years ago, the same time the mammoth and the Asian elephant are thought to have diverged. What evidence do scientists offer to support their idea that the African elephants are two different species? A) The elephants occupy two different niches in Africa. B) One species of elephant appeared much later than the other. C) The two elephant species have different physical characteristics. D) DNA analysis reveals that the two elephants are genetically different.