Reconstructing the colonization and demographic dynamics that gave rise to extant forests is essential to forecasts of forest responses to environmental changes. Classical approaches to map how population of trees changed through space and time largely rely on pollen distribution patterns, with only a limited number of studies exploiting DNA molecules preserved in wooden tree archaeological and subfossil remains. Here, we advance such analyses by applying high-throughput (HTS) DNA sequencing to wood archaeological and subfossil material for the first time, using a comprehensive sample of 167 European white oak waterlogged remains spanning a large temporal (from 550 to 9,800 years) and geographical range across Europe. The successful characterization of the endogenous DNA and exogenous microbial DNA of 140 (~83%) samples helped the identification of environmental conditions favouring long-term DNA preservation in wood remains, and started to unveil the first trends in the DNA decay process in wood material. Additionally, the maternally inherited chloroplast haplotypes of 21 samples from three periods of forest human-induced use (Neolithic, Bronze Age and Middle Ages) were found to be consistent with those of modern populations growing in the same geographic areas. Our work paves the way for further studies aiming at using ancient DNA preserved in wood to reconstruct the micro-evolutionary response of trees to climate change and human forest management.

The introduction of farming had far-reaching impacts on health, social structure and demography. Although the spread of domesticated plants and animals has been extensively tracked, it is unclear how these nascent economies developed within different environmental and cultural settings. Using molecular and isotopic analysis of lipids from pottery, here we investigate the foods prepared by the earliest farming communities of the European Atlantic seaboard. Surprisingly, we find an absence of aquatic foods, including in ceramics from coastal sites, except in the Western Baltic where this tradition continued from indigenous ceramic using hunter-gatherer-fishers. The frequency of dairy products in pottery increased as farming was progressively introduced along a northerly latitudinal gradient. This finding implies that early farming communities needed time to adapt their economic practices before expanding into more northerly areas. Latitudinal differences in the scale of dairy production might also have influenced the evolution of adult lactase persistence across Europe.

From 1989 to 1991, a rescue-dig took place at Poses, «Le Vivier- Le Clos-Saint-Quentin». The area studied is situated on the flood-plain, which explains in this place important alluvial deposits, and consequently exceptionnal conservation of neolithic and chalcolithic seulement levels. On four hectares, the excavation has induced the study of seven settlements and also secondary areas (particularly combustion structures of polynesian type and accumulation of blocks of sandstone). The two oldest settlements belong to the «post-rubané» cultures (Villeneuve-Saint-Germain, Cerny) and the five others to the chalcolithic cultures. The most important resuit concerns, on one hand, the first neolithisation of the country and, on the other hand, the development of a chrono-cultural framework for the Late Neolithic - Early Bronze Age transition. The excavations have shown the existence of original late neolithic features (assemblages 3 and 4), have confirmed the large impact of Bell Beakers espansion in a late time in the Lower Valley of the Seine River and their evolution (assemblages 5 and 6), and finally have allowed to discover an unknown chalcolithic feature (assemblage 7). This operation enables us also to approach the theme of the development of marginal lands in areas liable to flooding.

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