The african elephant genus contains two (or, arguably, three) living species; whereas, the asian elephant species is the only surviving member of the asian elephant genus, but can be divided into four subspecies. Although the fossil evidence is uncertain, scientists discovered genetic evidence that the elephant family shares distant ancestry with the sirenians (sea cows) and the hyraxes through gene comparisons. In the distant past, members of the hyrax family grew to large sizes, and it seems likely that the common ancestor of all three modern families was some kind of amphibious hyracoid. One theory suggests that these animals spent most of their time under water, using their trunks like snorkels for breathing. Modern elephants have retained this ability and are known to swim in that manner for up to 6 hours and 50 km (30 miles).
In the past, there was a much wider variety of elephant genera, including the mammoths, stegodons and deinotheria. There was also a much wider variety of species.The elephants of the genus loxodonta, known collectively as african elephants, are currently found in 37 countries in africa. African elephants are distinguished from asian elephants in several ways, the most noticeable being their ears which are much larger. The african elephant is typically larger than the asian elephant and has a concave back. Both african males and females have external tusks and are usually less hairy than their asian cousins. The world population of asian elephants – also called indian elephants – is estimated to be around 60,000, about a tenth of the number of african elephants.