Hominidae and Homo – discontinuity and continuity, « environnementalisme et comportementalisme »

The family Hominidae, starting with the split of the Panidae from the common ancestors Hominoidea, are comprising the two subfamilies Australopithecinae and Homininae. Because of the geographic division of their ancestors into a western and into an eastern group, the Panidae and Hominidae were never together. The eastern solution was the adaptation to an open habitat and the story of this adaptation is the story of the Hominidae – I have called it East Side Story ; it is a cladogenesis, a discontinuity. The Australopithecinae with three possible genera (Motopithecus, Pre‑Australopithecus, Australopithecus) and six possible species is more complex than it was thought.

The origin of Homo is a product of discontinuity and “environmentalism” again. Their oldest remains could be 2.5 to 3 m.y. old. The evolution of this genus is passing through 3 main steps : Homo habilis, Homo erectus, Homo sapiens, which are more looking like grades than true species and the evolution of Homo is looking like a continuum, an anagenesis, a phyletic gradualism. Tool‑making activity preceded Homo. With Homo, the cultural evolution which is also a continuity, is going successively, shown than biology, first, and then faster. The speeds of the biological and of the technological evolution are different and reverse.