Population kinetics in the Upper Palaeolithic in Western Europe

After 40 kyr BP, the distribution of archaeological sites shows that the occupation of the western-European peninsula, at the north of the Alpine arc, has the appearance of nodes of concentration, separated by vast zones which are either empty or with a negligible population density. The populational kinetics of the hunter-gatherers in this vast area is characterized by the permanence of a refuge zone located in northern Aquitaine. The leptokurtic aspect of the density distributions of sites observed from the Aurignacian to the Glacial Maximum but not at the Magdalenian suggest occasional long distance movement such as raids or opportunistic expeditions. During the Glacial Maximum, the response to the cold is marked by the complete abandonment of the northern peripheral zone, a contraction of the population mainly on the first peripheral zone surrounding the refuge zone, but without geographical change of position of the refuge zone. An optimistic estimate of the meta-population size of hunter-gatherers, which takes into account the change of area size due to the sea level variation, goes from the Aurignacian, 4000, to the Glacial Maximum 8000. During the Magdalenian a demographic explosion occurred with 40,000 individuals.