Though several morphological differences exist between African savannah elephants and forest elephants, it has been a challenge to conclusively determine the genetic relationship between them. Up until now they have been classified as subspecies (Loxodonta africana and Loxodonta cyclotis). In a recent study published in the journal PLoS Biology, scientists from the U.S., UK and Germany analyzed the DNA of modern elephants, as well as that of extinct mammoths and mastodons. They concluded that the divergence between the two African elephants occurred between 2.6 and 5.6 million years ago - about as ancient as the split between Asian elephants and mammoths. Study leader Alfred Roca of the University of Illinois at Urbana-Champaign says it is important to develop separate conservation plans for the two species in light of the findings. A little over a fifth of Africa’s 500,000 elephants are forest elephants, and their numbers, in particular, are dwindling rapidly from ivory poaching and habitat loss.