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The Hominidae (), also known as great apes〔"Great ape" is a common name rather than a taxonomic label, and there are differences in usage. It may exclude human beings ("humans and the great apes") or include them ("humans and nonhuman great apes").〕 or hominids, are a taxonomic family of primates that includes seven extant species in four genera: ''Pongo'', the Bornean and Sumatran orangutan; ''Gorilla'', the eastern and western gorilla; ''Pan'', the common chimpanzee and bonobo; and ''Homo'', the human.〔 Several revisions in classifying the great apes have caused the use of the term "hominid" to vary over time. Its original meaning referred only to humans (''Homo'') and their closest relatives. That restrictive meaning has now been largely assumed by the term "hominin", which comprises all members of the human clade after the split from the chimpanzees (''Pan''). (''See'' below, for a fuller discussion of related and very similar terms, at Terminology.) The current, 21st century, meaning of "hominid" refers to all the great apes including humans. Usage still varies, however, and some scientists and laypersons still use "hominid" in the original restrictive sense; the scholarly literature generally shows the traditional usage until around the turn of the 21st century. Within the taxon Hominidae, a number of extant and known extinct, that is, fossil, genera are grouped with the humans, chimpanzees, and gorillas in the subfamily Homininae; others with orangutans in the subfamily Ponginae (see classification graphic below). The most recent common ancestor of all Hominidae lived roughly 14 million years ago, when the ancestors of the orangutans speciated from the ancestral line of the other three genera.〔Dawkins R (2004) ''The Ancestor's Tale''.〕 Those ancestors of the Hominidae family had already speciated from the Hylobatidae family (the gibbons), perhaps 15 million to 20 million years ago.〔 == History == In the early Miocene, about 22 million years ago, there were many species of arboreally adapted primitive catarrhines from East Africa; the variety suggests a long history of prior diversification. Fossils at 20 million years ago include fragments attributed to ''Victoriapithecus'', the earliest Old World Monkey. Among the genera thought to be in the ape lineage leading up to 13 million years ago are ''Proconsul'', ''Rangwapithecus'', ''Dendropithecus'', ''Limnopithecus'', ''Nacholapithecus'', ''Equatorius'', ''Nyanzapithecus'', ''Afropithecus'', ''Heliopithecus'', and ''Kenyapithecus'', all from East Africa. At sites far distant from East Africa, the presence of other generalized non-cercopithecids, that is, non-monkey primates, of middle Miocene age—''Otavipithecus'' from cave deposits in Namibia, and ''Pierolapithecus'' and ''Dryopithecus'' from France, Spain and Austria—is further evidence of a wide diversity of ancestral ape forms across Africa and the Mediterranean basin during the relatively warm and equable climatic regimes of the early and middle Miocene. The most recent of these far-flung Miocene apes (hominoids) is ''Oreopithecus'', from the fossil-rich coal beds in northern Italy and dated to 9 million years ago. Molecular evidence indicates that the lineage of gibbons (family Hylobatidae), the lesser apes, diverged from that of the great apes some 18–12 million years ago, and that of orangutans (subfamily Ponginae) diverged from the other great apes at about 12 million years. There are no fossils that clearly document the ancestry of gibbons, which may have originated in a still-unknown South East Asian hominoid population; but fossil proto-orangutans, dated to around 10 million years ago, may be represented by ''Sivapithecus'' from India and ''Griphopithecus'' from Turkey. Species close to the last common ancestor of gorillas, chimpanzees and humans may be represented by ''Nakalipithecus'' fossils found in Kenya and ''Ouranopithecus'' found in Greece. Molecular evidence suggests that between 8 and 4 million years ago, first the gorillas (genus ''Gorilla''), and then the chimpanzees (genus ''Pan'') split off from the line leading to the humans. Human DNA is approximately 98.4% identical to that of chimpanzees when comparing single nucleotide polymorphisms (see human evolutionary genetics). The fossil record, however, of gorillas and chimpanzees is limited; both poor preservation—rain forest soils tend to be acidic and dissolve bone—and sampling bias probably contribute most to this problem. Other hominins probably adapted to the drier environments outside the African equatorial belt; and there they encountered antelope, hyenas, dogs, pigs, elephants, horses, and other forms becoming adapted to surviving in the East African savannas, particularly the regions of the Sahel and the Serengeti. The wet equatorial belt contracted after about 8 million years ago, and there is very little fossil evidence for the divergence of the hominin lineage from that of gorillas and chimpanzees—which split was thought to have occurred around that time. The earliest fossils argued by some to belong to the human lineage are ''Sahelanthropus tchadensis'' (7 Ma) and ''Orrorin tugenensis'' (6 Ma), followed by ''Ardipithecus'' (5.5–4.4 Ma), with species ''Ar. kadabba'' and ''Ar. ramidus''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hominidae」の詳細全文を読む スポンサード リンク
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