The name 'elephant' is coined from the Greek word for ivory, 'elephas'. The name largely refers to the tusks of the mammal. Elephants belong to the family Elephantidae. These magnificent terrestrial creatures are now studied as members of three distinct living species―the African Bush or Wild, the African Forest, and the Asian Elephant. Research reveals that other related species became extinct during the last ice age. Fossil remains highlight that mammoths survived till 2000 BC. Previously, the gigantic terrestrial mammals were classified in the order Pachydermata, because of their thick skin. However, the classification now recognizes the elephant as a member of the Proboscidea order.
A study of the evolution of elephants begins with the ancient Eocene. Gene comparisons have established genetic evidence of a linked ancestry with the sirenians and hyraxes. Fossil studies have proved that the hyrax family comprised amphibious hyracoids that grew to enormous sizes. A theory suggests that the mammals initially spent most of their time underwater and used their trunks as snorkels, hence, the growth. The debate continues as the modern elephant displays the distinct ability to swim for up to 6 hours at a stretch. The wider variety of genera that existed in the past included mammoths.
Research on anatomical and morphological data reveals a common ancestor for the elephant varieties that inhabit the planet today. The modern elephant is a relative of all the 350 proboscideans that existed over 50 million years ago. They are believed to have inhabited every region, except Antarctica and Australia. The first fossils unearthed in 1904 in Egypt revealed the evolution stage characterized by enlarged incisors or tusks, and a lifestyle similar to that of a hippopotamus. Evolution of the modern elephant also bears traces of the palaeomastodon and gomphotheres families. This root of the ancestry is tapped due to features such as the elongated nose and enlarged incisors.
Though a popular belief is that the mastodons and mammoths, the other elephant ancestors, were related, research reveals that mastodons had heavier frames and flattened heads in comparison to the mammoths. The confusion mainly arises due to the fact that both the species inhabited the same regions. Further up, and on the last rung of the evolutionary tree, is the Primelephas, the oldest ancestor of Elephantidae, a family that inhabited the planet around 7 million years ago. The branches of the modern elephant's evolutionary tree seems to move along two distinct segments from Primelephas. While the Loxodonta evolved into the modern African elephant, the Elephas evolved into the Asian elephant species.
The Proboscidea order now has only three major surviving species. 'Motty', a hybrid calf at the Chester Zoo, would have been another rung in elephant evolution. The successful hybridization between an African and Asian elephant resulted in African elephant cheeks, ears, and legs, and Asian elephant toenail numbers and single trunk finger. However, the calf succumbed to infection and is now a mounted specimen at London's Natural History Museum. The future of the order is threatened due to increasing ivory trade, indiscriminate poaching, and ongoing cultivation of their natural habitats. There are a number of problems associated with elephant reserves too. Elephant rage and foraging activities are known to break down borders between winter and spring breeding areas. The gigantic mammals also inflict enormous damage to the local landscapes they inhabit. Nevertheless, the dwarfed fauna and high adaptability to human intervention continue to make the elephant a natural wealth. They are an inseparable part of cultures across the world, and are heralded for their wisdom and memory.