Dwarf elephants are prehistoric members of the order
Proboscidea which, through the process of
allopatric speciation on islands, evolved much smaller body sizes (around 1.5-2.3 metres) in comparison with their immediate ancestors. Dwarf elephants are an example of
insular dwarfism, the phenomenon whereby large terrestrial vertebrates (usually mammals) that colonize islands evolve dwarf forms, a phenomenon attributed to adaptation to resource-poor environments and selection for early maturation and reproduction. Some modern populations of
Asian elephants have also undergone size reduction on islands to a lesser degree, resulting in populations of
pygmy elephants.