According to some researchers, wearing clothes may predate early human global migrations by an additional 70,000 years. In this case, the migrations were themselves facilitated by the innovation of clothing. It is believed that earlier species of archaic humans, including Homo neanderthalensis, Homo rhodesiensis, Homo heidelbergensis, Homo antecessor, either were not able to create true clothing, or were not able to do it as well as Homo sapiens sapiens (anatomically modern humans). At most, as in the case of Homo neanderthalensis, they are believed to have worn only capes, if any coverings at all. This lack of behavioral adaptation, in turn, may have contributed to their eventual extinction during ancient climate changes when they may have succumbed to hypothermia, frostbite and other cold ailments.
The amount of clothing worn depends on functional considerations, such as a need for warmth, as well as social circumstances. In some situations, a minimum amount of clothing or none at all may be considered socially acceptable, while in others much more clothing may be expected. Social considerations involve cultural issues of modesty, subjective decency and social norms, besides other considerations, and these may depend on the context. There may also be legal considerations.
Full nudity refers to complete nudity, while partial nudity refers to less than full nudity, with parts of the body covered in some manner. The term "partial nudity" is sometimes used to refer to exposure of skin beyond what the person using the expression considers to be within the limits of modesty. If the exposure is within the standards of modesty of a given culture and setting (e.g. wearing a bikini at a non-nude beach), terms such as nudity, partial or otherwise, are not normally used. If however, the degree of exposure exceeds the cultural norms of the setting, or if the activity or setting includes nudity as an understood part of its function, such as a nude beach, terminology relating to nudity and degrees thereof are typically used. Toplessness is regarded by most people as partial nudity.
Full frontal nudity describes a state of full nudity with the subject facing towards the viewer, with the whole front of the body exposed, including intimate parts such as a man's penis or woman's vulva. Partial frontal nudity typically only refers to the exposure of the breasts. Non-frontal nudity describes nudity where the whole back side of the body, including the buttocks, is exposed, or a side-view from any other direction.
Hair probably evolved in mammals before about 220 million years ago. The closest living genetic relatives of humans, apes and especially chimpanzees, possess an almost complete covering of fur.