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Biology subjects

Bar-Yosef, O.

Publications and source records attributed to Bar-Yosef, O..

2 recordsLinked to original sources

Paleolithic DNA from the Caucasus reveals core of West Eurasian ancestry

The earliest ancient DNA data of modern humans from Europe dates to [~]40 thousand years ago1-4, but that from the Caucasus and the Near East to only [~]14 thousand years ago5,6, from populations who lived long after the Last Glacial Maximum (LGM) [~]26.5-19 thousand years ago7. To address this imbalance and to better understand the relationship of Europeans and Near Easterners, we report genome-wide data from two [~]26 thousand year old individuals from Dzudzuana Cave in Georgia in the Caucasus from around the beginning of the LGM. Surprisingly, the Dzudzuana population was more closely related to early agriculturalists from western Anatolia [~]8 thousand years ago8 than to the hunter-gatherers of the Caucasus from the same region of western Georgia of [~]13-10 thousand years ago5. Most of the Dzudzuana populations ancestry was deeply related to the post-glacial western European hunter-gatherers of the Villabruna cluster3, but it also had ancestry from a lineage that had separated from the great majority of non-African populations before they separated from each other, proving that such Basal Eurasians6,9 were present in West Eurasia twice as early as previously recorded5,6. We document major population turnover in the Near East after the time of Dzudzuana, showing that the highly differentiated Holocene populations of the region6 were formed by Ancient North Eurasian3,9,10 admixture into the Caucasus and Iran and North African11,12 admixture into the Natufians of the Levant. We finally show that the Dzudzuana population contributed the majority of the ancestry of post-Ice Age people in the Near East, North Africa, and even parts of Europe, thereby becoming the largest single contributor of ancestry of all present-day West Eurasians.

genetics

Adaptation of the FADS gene family in Europe: Variation across time, geography and subsistence

Fatty acid desaturase (FADS) genes encode rate-limiting enzymes for the biosynthesis of omega-6 and omega-3 long chain polyunsaturated fatty acids (LCPUFAs). This biosynthesis is essential for individuals subsisting on LCPUFAs-poor, plant-based diets. Positive selection on FADS genes has been reported in multiple populations, but its presence and pattern in Europeans remain elusive. Here, with analyses of ancient and modern DNA, we demonstrated that positive selection acted on the same FADS variants both before and after the advent of farming in Europe, but on opposite alleles. Selection in recent farmers also varied geographically, with the strongest signal in Southern Europe. These varying selection patterns concur with anthropological evidence of differences in diets, and with the association of recently-adaptive alleles with higher FADS1 expression and enhanced LCPUFAs biosynthesis. Genome-wide association studies revealed associations of recently-adaptive alleles with not only LCPUFAs, but also other lipids and decreased risk of several inflammation-related diseases.

genomics