If the stages of this second conquest of the Earth start to be known, a scientific controversy divides the specialists: several theses clash as for the origin of Homo sapiens. Is it, like its ancestor Homo erectus, originating in only one area (in fact Africa, once again) or the change did it occur in various areas of the world where Homo erectus was present? Certain geneticists and linguists think of being able to prove the anteriority of the first African representatives of Homo sapiens by the thesis of the monocentrism.

However, the archaeological traces seem to militate in favor of the polycentrism. Current humanity would have had several cradles, and each one of them would have been connected to its neighbors following the nomadism of the populations. The passage of Homo erectus with Homo sapiens was carried out gradually. The physical and intellectual transformations do not appear contemporary of an area with another. It seems that certain characteristics of the human independent groups (Asian, Aborigènes of Australia, circum-Mediterranean, African) evolved over long periods, roughly in the zones which these people occupy still today. In fact, it appears difficult to admit that the descendants of hypothetical “African Eve” completely replaced, everywhere in the world, the groups of Homo erectus, whose one can measure, by the fossils, the evolution continues and local towards Homo sapiens. The example of the Middle East seems particularly convincing. The first modern men of the area, resulting from a native Homo erectus, cohabited a long time with the last Neanderthal men, towards - 100 ' 000 years. One distinguishes there, in the actual position of knowledge, no irruption of a modern man who would have from Africa.  

At all events, towards -100 ' 000 years, there seems to have been a separation in two groups already, the Eastern one and the Westerner, which are at the origin of the current people of the Earth. This separation could have taken place in Eastern Africa or in the Middle East. But of innumerable interbreedings with the indigenous former populations led to the current diversity of the people of the Earth. This diversity hardly has, in fact, more than 25 ' 000 to 30 ' 000 years, and sometimes much less. From - 50 ' approximately 000 years, many migrations were recognized. They are often related to the evolution of the climate during the last glaciation, which, of - 85 ' 000 to -10 ' 000 years, upset the surface of planet. On several occasions, icecaps covered north with Eurasia and America. The climate, excessively cold, was unfavourable to the man in many areas now moderate.

In parallel, the sea level dropped considerably. It was, for example, to -110 m compared to the current level 18 ' 000 years ago, thus discovering immense spaces which allowed connections dry foot between areas now separated by stretches of water. On the contrary, certain periods were more lenient, in particular towards -100 ' 000 and -35 ' 000 years, which supported the human expansion. From -10 ' 000 years, the end of the glaciation led in a few millenia to the current climate and the man could occupy the whole of the Earth.  

The man of Neandertal

The man of Neandertal corresponds to a kind of paléanthropien, thus named according to the valley of Neander, near of Düsseldorf (Germany), where the incomplete remainders of a human skeleton were discovered in 1856 in the cave of Feldhofer.  

Of small size (approximately 1.55 m), equipped with a flattened skull convex in chignon with the back, with a fleeing face and strong orbital pads, the man of Neandertal had an identical cranial capacity, even higher, with that of the current man, without however expressing the same development of the frontal lobes. Distribute in all Europe and in the Middle East, the Neanderthal men set up a relatively homogeneous group. Typical representatives of the Paleolithic means, they appeared 80 ' approximately 000 years ago - they are the representatives of the long evolution of the subspecies Homo sapiens neandertalensis which seems to appear in Europe there is more than 300 ' 000 years - and developed during the first two phases of the glaciation of Würm to disappear towards 35 ' 000 before our era. They constituted of the human lines adapted to the cold climate.  

Even if it is not sure that the Neanderthal men are the persons in charge, single at least, of industry moustérienne (this one is, in Israel, associated with fossils with more modern men), they all the same left testimonies of industries remarkably specialized and characterized by the technique of Levallois cutting up. Certain indices of spiritual concerns (burials), artistic (ocher traces), and perhaps medical are also attested.

In addition, the end of the time moustérienne does not correspond to the extinction of the Neanderthal men, since a skeleton of this type was found in a level châtelperronien in Saint-Césaire (Charente-Maritime). It is thus during the Paleolithic superior that they gradually left the place to the Homo sapiens sapiens, i.e. with the man of the current type.

The man of Cro-Magnon

The man of Cro-Magnon represents the oldest specimen of the kind Homo sapiens sapiens. Appeared some 40 ' 000 years ago, during the recent phase of the last glaciation of Würm, it is distinguished from the man of Neandertal by more evolved physical characteristics, which are very close to the modern man (big size, robustness, bulky and lengthened skull). Both would be the result of distinct lines, resulting from a common ancestor, Homo erectus.

The man of Cro-Magnon lived still primarily of hunting; he lived rock shelters, caves, or sometimes even of the arranged campings. He controlled fire and buried his deaths. He left testimonies of sculpture and painting which are among the oldest works of art of humanity.