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Biology subjects

Rottier, S.

Publications and source records attributed to Rottier, S..

2 recordsLinked to original sources

Effects of ancestry, agriculture, and lactase persistence on the stature of prehistoric Europeans

Ancient DNA has revolutionized our understanding of human evolutionary history, but studies focusing solely on genetic variation tell an incomplete story by neglecting phenotypic outcomes. The relationships between genotype and phenotype can change over time, making it desirable to study them directly in ancient populations rather than present-day data. Here, we present a large-scale integration of ancient genomic and phenotypic data, analyzing femur length as a proxy for stature in 568 individuals with published whole-genome ancient DNA data across western Eurasia. Polygenic scores derived from modern European and East Asian genome-wide association studies retain predictive power in ancient populations, explaining up to 10% of phenotypic variance. Contrary to longstanding archaeological hypotheses, we find that Neolithic populations were only modestly shorter than preceding Mesolithic groups, with differences at least partly attributable to genetic rather than environmental factors, challenging narratives of systematic stature decline following the transition to agriculture. Finally, we find that the lactase persistence allele had a large positive effect on stature in ancient individuals (0.24 standard deviations), even though it shows no association with height in modern populations. This gene-environment interaction highlights the limitation of using present-day genetic data to infer past phenotypic relationships. Our results underscore the value of integrating genetic and morphological data from ancient populations to reconstruct the dynamics of human adaptation.

genetics↗

Using Y-chromosome capture enrichment to resolve haplogroup H2 shows new evidence for a two-Path Neolithic expansion to Western Europe

Uniparentally-inherited markers on mitochondrial DNA (mtDNA) and the non-recombining regions of the Y chromosome (NRY), have been used for the past 30 years to investigate the history of humans from a maternal and paternal perspective. Researchers have preferred mtDNA due to its abundance in the cells, and comparatively high substitution rate. Conversely, the NRY is less susceptible to back mutations and saturation, and is potentially more informative than mtDNA owing to its longer sequence length. However, due to comparatively poor NRY coverage via shotgun sequencing, and the relatively low and biased representation of Y-chromosome variants on capture arrays such as the 1240K, ancient DNA studies often fail to utilize the unique perspective that the NRY can yield. Here we introduce a new DNA enrichment assay, coined YMCA (Y-mappable capture assay), that targets the "mappable" regions of the NRY. We show that compared to low-coverage shotgun sequencing and 1240K capture, YMCA significantly improves the coverage and number of sites hit on the NRY, increasing the number of Y-haplogroup informative SNPs, and allowing for the identification of previously undiscovered variants. To illustrate the power of YMCA, we show that the analysis of ancient Y-chromosome lineages can help to resolve Y-chromosomal haplogroups. As a case study, we focus on H2, a haplogroup associated with a critical event in European human history: the Neolithic transition. By disentangling the evolutionary history of this haplogroup, we further elucidate the two separate paths by which early farmers expanded from Anatolia and the Near East to western Europe.

genetics↗