Clarence (2012) suggests that afro-textured hair may have initially evolved because of an adaptive need amongst humans’ early hominid ancestors for protection against the intense UV radiation of the sun in Africa. With regard to the hypothesized recent African origin of modern humans, the author argues that afro-textured hair was the original hair texture of all modern humans prior to the “Out-of-Africa” migration that populated the rest of the globe.
According to Clarence (2012), afro-textured hair may have been adaptive for the earliest modern humans in Africa because the relatively sparse density of such hair, combined with its elastic helix shape, results in an airy effect. The resulting increased circulation of cool air onto the scalp may have thus served to facilitate the body-temperature-regulation system of hominids while they lived on the open savannah. Afro-hair requires more moisture than straight hair and tends to shrink when dry. Instead of sticking to the neck and scalp when damp (as do straighter textures), unless completely drenched it tends to retain its basic springiness. The trait may have been retained and/or preferred among many anatomically modern populations in equatorial areas, such as Polynesians, Micronesians, Melanesians, Australoids and the Negrito, because of its contribution to enhanced comfort levels under tropical climate conditions.