Traces paléoanthropologiques et archéologiques d'une transition démographique néolithique en Europe

Abstract
Une base de données de 68 nécropoles mésolithiques et néolithiques d'Europe (réduites à 36 à cause d'un biais d'échantillonnage) est mise en œuvre dans ce travail; elle représente un échantillon de la distribution spatiotemporelle d'une information démographique non conventionnelle : la proportion des immatures dans l'échantillon des squelettes. Son analyse permet de détecter, entre le Mésolithique et le Néolithique, le signal d'un important changement démographique. Caractérisé par une rupture nette d'avec l'ancien régime stationnaire des chasseurs-collecteurs, sur la durée relativement brève d'environ 500 ans, on l'appelle "transition démographique néolithique " . Ce résultat est confronté à une catégorie de données archéologiques indépendante : les enceintes néolithiques, considérées comme des réponses, dans l'organisation de l'espace social, à la croissance de la densité de population. On montre que l 'échantillon de 700 sites européens suit une variation quantitative compatible avec la transition démographique détectée dans les nécropoles. Le rythme et la force de la pression démographique envisageable d'après les données anthropologiques trouvent donc un écho bienvenu dans les formes d'organisation de l'habitat.This study begins by establishing a database of 68 European Mesolithic and Neolithic cemeteries (reduced to 36 due to a sampling bias), representing a sample of the space-time distribution of an unconventional kind of demographic evidence: the proportion of subadults between 5 and 19 years old in the sample of skeletons aged 5 or over. Its analysis reveals a signal of important demographic change, between the Mesolithic and the Neolithic, called the "Neolithic demographic transition ". The signal is characterized by a 70% increase in the mean proportion of subadults in cemeteries, which shifts from 16 to 27% between the Mesolithic and the Neolithic. In counter-intuitive manner, the rise in the proportion of subadults in cemeteries principally reflects the birth rate, and beyond this the rate of growth, through broadening of the base of the age pyramid of the living population. This Neolithic demographic transition is characterized by a clear break with the old, stationary hunter-gatherer regime, over a relatively short period of about 500 years. Using the technique of palaeodemographic estimators, the estimated growth rate varies from -0.3% to +1.3% (±1.07%) during the Mesolithic-Neolithic transition. This result is confronted with an independent category of archaeological data: Neolithic enclosures, considered as responses, through the organization of social space, to growth in population density. About 700 sites in central and western Europe, from N.H. Andersen's inventory (1997), are taken into consideration. Their distribution in time (calibrated C14) clearly shows the existence of two distinct phenomena, separated by a millennium: the first culminates in the first half of the 5th millennium and the second in the 4th. Yet analysis of the temporal distance of each site from the start of the "Neolithic" way of life in its region reveals that the sample of 700 sites varies quantitatively in a manner compatible with the demographic transition detected in cemeteries. The frequency of enclosures generally reaches a peak between 600 and 900 years after the beginnings of an agricultural way of life in a region. The rhythm and force of demographic pressure that can be envisaged from the anthropological data thus find a welcome echo in forms of settlement organization. The link between these two categories of biological and cultural evidence - the frequency of subadults in cemeteries and the enclosure systems - is population growth following the establishment of a farming way of life. Both provide the signal of a relatively abrupt demographic change and they also converge in the estimation of the speed at which this first demographic transition in Europe generally took place. The phenomenon reaches a peak about 500 years after "Neolithization " of a given region for the anthropological data, and about 600-900 years for the enclosure data. The demographic change which produced relatively important population growth thus occurred over quite a short time-span. Detection of the signal for this transition depends on the space-time evidence available; the demographic pattern obtained and the resulting estimates are thus a kind of average on a continental scale. This does not mean that the Neolithic demographic transition happened at the same speed everywhere, especially on the periphery of Europe. Geographical differentiation in the process must certainly be envisaged, depending on the regional speed and intensity of the establishment of the "Neolithic " way of life.Bocquet-Appel Jean-Pierre, Dubouloz Jérôme. Traces paléoanthropologiques et archéologiques d'une transition démographique néolithique en Europe. In: Bulletin de la Société préhistorique française, tome 100, n°4, 2003. pp. 699-714