Recent paleogenetic studies have confirmed that the spread of the Neolithic across Europe was neither genetically nor geographically uniform. To extend existing knowledge of the mitochondrial European Neolithic gene pool, we examined six samples of human skeletal material from a French megalithic long mound (c.4200 cal BC). We retrieved HVR-I sequences from three individuals and demonstrated that in the Neolithic period the mtDNA haplogroup N1a, previously only known in central Europe, was as widely distributed as western France. Alternative scenarios are discussed in seeking to explain this result, including Mesolithic ancestry, Neolithic demic diffusion, and long-distance matrimonial exchanges. In light of the limited Neolithic ancient DNA (aDNA) data currently available, we observe that all three scenarios appear equally consistent with paleogenetic and archaeological data. In consequence, we advocate caution in interpreting aDNA in the context of the Neolithic transition in Europe. Nevertheless, our results strengthen conclusions demonstrating genetic discontinuity between modern and ancient Europeans whether through migration, demographic or selection processes, or social practices.

The ancestry of the long mound has long been a key focus in debates on the origins of monumental and megalithic architectures in western France. Typological schemes and absolute dates have alike been invoked in support of different models of monument development, but with limited success. Recent excavations at Prissela-Charriere, a 100-metre long mound in the Poitou-Charentes region, have emphasised the importance of internal structure and the complex process of modification and accretion by which many long mounds achieved their final form and dimensions. Excavations have revealed an early megalithic chamber in a dry-stone rotunda, that was progressively incorporated in a short long mound, then in the 100 m long mound we see today, which contains at least two further chamber tombs. The wide range of monument forms present in western and northern France during the 5th millennium BC suggests that the issue of monument origins must be viewed in a broad inter-regional perspective, within which a number of individual elements could be combined in a variety of different ways. Consideration of seven specific elements, including the shape of the mound, the position and accessibility of the chamber, and the significance of above-ground tomb chambers as opposed to graves or pits leads us to propose a polygenic model for the origins of the long mounds and related monuments of western France.The Neolithic chambered tombs of north-west Europe, despite their prominent architecture, have proved extraordinarily difficult to date. The crucial problem arises from the fact that those elements that are susceptible to radiocarbon dating (such as charcoal, and even human bone) are only indirectly or insecurely associated with the construction phase of the monument itself. This has meant that chronological schemes for these tombs have frequently relied on the morphology and typology of their structure. The first serious attempts to arrange the monuments in a typological series were made in the 19th century. In 1868, for example, W.C. Lukis published a brief account of 'the various forms of monuments, commonly called dolmens, in Brittany, pointing out a progress in their architectural construction, with an attempt to reduce them to

Cet article présente le résultat de six années de recherches sur le tumulus C de la nécropole mégalithique de Péré à Prissé-la-Charrière (Deux-Sèvres). Ce monument déforme trapézoïdale se présentait sous la forme d'une butte de 115 m de long pour 30 m de large et 4 m de haut. Il a été construit en plusieurs étapes. La plus ancienne reconnue à ce jour correspond à un petit monument funéraire long de 7,20 m d'est en ouest, et large de 8,80 m. Construit essentiellement en terre, il contenait un « coffre » largement ouvert vers l'extérieur et ceinturé par une chemise de pierres. Dans un second temps, l'entrée du coffre a été obturée et le monument a été étendu vers l'est afin d'obtenir un tertre allongé de 23 m de long. L'ensemble était circonscrit par un fossé périphérique. Puis, intervient la construction d'un tumulus trapézoïdal de 100 m de long qui recouvre le monument précédent à l'ouest. Il contient au moins une chambre mégalithique de plan quadrangulaire desservie par un couloir d'accès débouchant sur la façade septentrionale, au tiers de sa longueur environ en partant de son extrémité occidentale. Cette chambre funéraire a également livré du mobilier attribuable au Néolithique moyen. Nous discuterons de l'apport de ces travaux pour la connaissance du mégalithisme régional et en particulier du problème de ses origines.