Fine-Scale Population Structure in Humans

Biswas et al. Genome-wide Insights into the Patterns and Determinants of Fine-Scale Population Structure in Humans. The American Journal of Human Genetics, Volume 84, Issue 5, 641-650 15 May 2009 doi:10.1016/j.ajhg.2009.04.015

Studying genomic patterns of human population structure provides important insights into human evolutionary history and the relationship among populations, and it has significant practical implications for disease-gene mapping. Here we describe a principal component (PC)-based approach to studying intracontinental population structure in humans, identify the underlying markers mediating the observed patterns of fine-scale population structure, and infer the predominating evolutionary forces shaping local population structure. We applied this methodology to a data set of 650K SNPs genotyped in 944 unrelated individuals from 52 populations and demonstrate that, although typical PC analyses focus on the top axes of variation, substantial information about population structure is contained in lower-ranked PCs. We identified 18 significant PCs, some of which distinguish individual populations. In addition to visually representing sample clusters in PC biplots, we estimated the set of all SNPs significantly correlated with each of the most informative axes of variation. These polymorphisms, unlike ancestry-informative markers (AIMs), constitute a much larger set of loci that drive genomic signatures of population structure. The genome-wide distribution of these significantly correlated markers can largely be accounted for by the stochastic effects of genetic drift, although significant clustering does occur in genomic regions that have been previously implicated as targets of recent adaptive evolution.

Link; supplementary material; press release.

Ancient Basque DNA

Press release:

Ancient DNA: reconstruction of the biological history of Aldaieta necropolis

A research team from the Department of Genetics, Physical Anthropology & Animal Physiology in the Faculty of Science and Technology at the Leioa campus of the University of the Basque Country (UPV/EHU), and led by Ms Concepción de la Rúa, has reconstructed the history of the evolution of human population and answered questions about history, using DNA extracted from skeleton remains.

[. . .]

Aldaieta brings together certain important features which make this site a prime archaeological and historical record and its conservation an important task of restoration and study. In this vein, the Department of Genetics, Physical Anthropology & Animal Physiology in the Faculty of Science and Technology at the University of the Basque Country (UPV/EHU), has undertaken a study of DNA in the necropolis at Aldaieta (Araba).

[. . .]

Despite the problems inherent working with ancient DNA, the methodology drawn up for the current work as well as the precautions and criteria of authentication undertaken have enabled reliable and verifiable results of the population buried at Aldaieta to be obtained.

Within the great homogeneity of the mitochondrial lines on the European continent, the genetic substrate of the population buried at Aldaieta falls within the variability of that expressed by current populations on the Cantabrian coast and Atlantic axis, thereby indicating the existence of genic flow between these human groups in ancient times.

Besides the characterisation of the mitochondrial genome, they have carried out the characterisation of the chromosome Y, using techniques focused on ancient DNA, an have shown the existence of family relationships within the necropolis, given that certain mitochondrial lines have a particular distribution, the grouping of individuals belonging to the same line having been discovered at nearby burial sites. Besides, there exists a significant differentiation gender wise, men having qualitatively and quantitatively more important funerary artefacts than women.

Some UPV/EHU pdfs are available here, though I don't recall seeing any ancient Y-DNA results published by this group as yet.

Update: Here is a web page of the lead investigator mentioned in the release. No recent publications listed.