The effect of area and isolation on insular dwarf proboscideans

摘要: Aim We investigated the hypothesis that insular body size of fossil elephants is directly related to isolation and surface area focal islands. Location Palaeo-islands worldwide. Methods We assembled data on geographical characteristics (area isolation) islands evolution palaeo-insular species for 22 across 17 islands. Results Our results support generality island rule in sense all but one experienced dwarfism islands. The smallest generally harbour elephants. We found no declines with isolation. Body weakly positively correlated proboscideans as a whole, more strongly Stegodontidae when considered separately. Average decrease much higher competitors are present. Main conclusions Body not significantly an island. Surface area, however, significant predictor size. correlation positive relatively weak; c. 23% variation explained by area. seems most influenced ecological interactions competitors, possibly followed time Elephants exhibited far extreme cases than extant mammals, which consistent substantially extended period deep geological selective pressures could act these populations.