74 research outputs found

    Selective sweep on human amylase genes postdates the split with Neanderthals

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    Humans have more copies of amylase genes than other primates. It is still poorly understood, however, when the copy number expansion occurred and whether its spread was enhanced by selection. Here we assess amylase copy numbers in a global sample of 480 high coverage genomes and find that regions flanking the amylase locus show notable depression of genetic diversity both in African and non-African populations. Analysis of genetic variation in these regions supports the model of an early selective sweep in the human lineage after the split of humans from Neanderthals which led to the fixation of multiple copies of AMY1 in place of a single copy. We find evidence of multiple secondary losses of copy number with the highest frequency (52%) of a deletion of AMY2A and associated low copy number of AMY1 in Northeast Siberian populations whose diet has been low in starch content

    Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe

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    Archaeological evidence indicates that pig domestication had begun by ~10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ~8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local Euro-pean wild boars, although it is also possible that European wild boars were domesticated independently without any genetic con-tribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process

    STR-genotyping from human medieval tooth and bone samples

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    International audienceWe extracted the DNA contained in samples of bones and teeth from 10 skeletons excavated from the Gravette site (400-1000 AD, south of France). Ancient DNA was analysed by autosomal short tandem repeats (STRs). The DNA present in these ancient remains appeared very degraded, but nevertheless, better conserved in tooth than in bone samples. Moreover, we showed that the DNA extracted from ancient dental pulp was not exempt from polymerase chain reaction (PCR) inhibitors, which could result from extreme DNA fragmentation. An adapted protocol with a supplementary step of purification removed this inhibition

    New Ceramic Data from East Kalimantan: The cord-marked and red-slipped sherds of Liang Abu's layer 2 and Kalimantan's pottery chronology

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    https://pacificarchaeology.org/index.php/journal/article/view/126International audienceArchaeological research in the Liang Abu rock shelter (East Kalimantan) led to the discovery and analysis of a pot-tery assemblage including red-slipped, cord-marked and incised pottery sherds, radiocarbon dated to 1672 ± 21 BP and 1524 ± 22 BP. In order to discuss our findings we undertake a reappraisal of the pottery material and associated radiocarbon dates from archaeological sites on Borneo Island, which provide us with an appropriate framework for a comparative analysis. This allows us to to include the inland region of Kalimantan in the technological network of Neolithic Island South East Asia
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