The wild boar (Sus scrofa), also known as the wild swine, Eurasian wild pig, or simply wild pig, is a suid native to much of Eurasia, North Africa, and the Greater Sunda Islands. Human intervention has spread its distribution further, making the species one of the widest-ranging mammals in the world, as well as the most widely spread suiform. Its wide range, high numbers, and adaptability mean that it is classed as least concern by the IUCN and it has become an invasive species in part of its introduced range. The animal probably originated in Southeast Asia during the Early Pleistocene, and outcompeted other suid species as it spread throughout the Old World. As of 1990, up to 16 subspecies are recognized, which are divided into four regional groupings based on skull height and lacrimal bone length. The species lives in matriarchal societies consisting of interrelated females and their young (both male and female). Fully grown males are usually solitary outside the breeding season. The grey wolf is the wild boar's main predator throughout most of its range, except in the Far East and the Lesser Sunda Islands, where it is replaced by the tiger and Komodo dragon, respectively. It has a long history of association with humans, having been the ancestor of most domestic pig breeds and a big-game animal for millennia. Boars have also re-hybridized in recent decades with feral pigs; these boar–pig hybrids have become a serious pest animal in Australia, Canada, United States, and Latin America. As true wild boars became extinct in Great Britain before the development of Modern English, the same terms are often used for both true wild boar and pigs, especially large or semi-wild ones. The English 'boar' stems from the Old English bar, which is thought to be derived from the West Germanic *bairaz, of unknown origin. Boar is sometimes used specifically to refer to males, and may also be used to refer to male domesticated pigs, especially breeding males that have not been castrated. 'Sow', the traditional name for a female, again comes from Old English and Germanic; it stems from Proto-Indo-European, and is related to the Latin: sus and Greek hus, and more closely to the New High German Sau. The young may be called 'piglets'. The animals' specific name scrofa is Latin for 'sow'. In hunting terminology, boars are given different designations according to their age: MtDNA studies indicate that the wild boar originated from islands in Southeast Asia such as Indonesia and the Philippines, and subsequently spread onto mainland Eurasia and North Africa. The earliest fossil finds of the species come from both Europe and Asia, and date back to the Early Pleistocene. By the late Villafranchian, S. scrofa largely displaced the related S. strozzii, a large, possibly swamp-adapted suid ancestral to the modern S. verrucosus throughout the Eurasian mainland, restricting it to insular Asia. Its closest wild relative is the bearded pig of Malacca and surrounding islands.