Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

: Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants

Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

Publisher Copyright: © 2023, The Author(s).Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants.Peer reviewe

Chapitre 2. Sous-emploi et inadéquation professionnelle

Introduction Les indicateurs traditionnels du marché du travail ne parviennent pas à saisir les caractéristiques distinctives des pays en développement (PED), ainsi que la manière dont ces marchés s’ajustent. L’absence d’assurance-chômage, l’importance de l’emploi dans le secteur informel, la faiblesse de la régulation par l’État, entre autres, impliquent que les indicateurs de quantité (mesurés par le taux de chômage) soient moins pertinents. Dans ce contexte, les changements de qualité de l..

Quelle stratégie déchantillonnage pour évaluer l'impact d'un projet d'urbanisation dans un bidonville de Djibouti ?

nonouirecherchenationa

Migrations, natalité et solidarités familiales : La société de Mayotte en pleine mutation

Les mobilités sont très prégnantes à Mayotte et recomposent la population : en 2015, plus d’un adulte sur deux vivant à Mayotte n’y est pas né. Les natifs d’Anjouan sont les plus nombreux (30 %). Quatre résidents sur dix, âgés de 18 à 79 ans, sont ainsi de nationalité étrangère, la moitié d’entre eux étant en situation administrative irrégulière. L’émigration est également forte. En 2012, aux mêmes âges, 26 % des natifs de Mayotte et résidant en France vivent en dehors du département, et même 45 % des 18-24 ans. Par ailleurs, 30 % des adultes nés à Mayotte, et qui y résident, ont déjà séjourné plus de six mois en dehors de l’île. Le modèle familial mahorais repose sur deux fondements essentiels : le mariage et une fécondité élevée. Mais avec la généralisation de la scolarisation et notamment celle des femmes, les schémas traditionnels évoluent. Les solidarités familiales constituent un ciment essentiel de la cohésion de la société mahoraise. Dans un contexte de forte précarité, l’entraide financière régulière y est deux fois plus fréquente que dans les autres DOM. En outre, quatre personnes sur dix apportent une aide non financière à leur entourage, tout particulièrement pour la garde d’enfants ou pour aider les personnes âgées

Ross River Virus Seroprevalence, French Polynesia, 2014–2015

Ross River virus (RRV), spread by Aedes and Culex mosquitoes, is the most commonly transmitted arbovirus in Australia. A serosurvey of blood donors in French Polynesia during 2011–2013 suggested that RRV circulated without being detected. We report RRV circulation in French Polynesia based on further screening of blood samples collected during 2014–2015

Limits of calcium isotopes diagenesis in fossil bone and enamel

International audienceDiagenesis has been recognized for decades to significantly alter the trace elements biogenic signatures in fossil tooth enamel and bone that are routinely used for paleobiological and paleoenvironmental reconstructions. This signature is modified during diagenesis according to a complex continuum between two main processes, addition and substitution. For an additive-like, or early diagenesis, the trace elements biogenic profiles can be restored by leaching secondary minerals, but this technique is inefficient for a substitutive-like, or extensive diagenesis for which secondary trace elements are incorporated into the biogenic mineral. This scheme is however unclear for Ca, the major cation in tooth enamel and bone hydroxylapatite, whose stable isotope composition (δ44/42Ca) also conveys biological and environmental information. We present a suite of leaching experiments for monitoring δ44/42Ca values in artificial and natural fossil enamel and bone from different settings. The results show that enamel δ44/42Ca values are insensitive to an additive-like diagenesis that involves the formation of secondary Ca-carbonate mineral phases, while bone shows a consistent offset toward 44Ca-enriched values, that can be restored to the biogenic baseline by a leaching procedure. In the context of a substitutive-like diagenesis, bone exhibits constant δ44/42Ca values, insensitive to leaching, and shows a REE pattern symptomatic of extensive diagenesis. Such a REE pattern can be observed in fossil enamel for which δ44/42Ca values are still fluctuating and follow a trophic pattern. We conclude that Ca isotopes in fossil enamel are probably not prone to extensive diagenesis and argue that this immunity is due to the very low porosity of enamel that cannot accommodate enough secondary minerals to significantly modify the isotopic composition of the enamel Ca pool