The peopling of Greenland: further insights from the analysis of genetic diversity using autosomal and X-chromosomal markers

Abstract

The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence of a sex-biased, admixed genetic background. This work further explores the genetics of the Greenlanders by analysing autosomal and X-chromosomal data to obtain deeper insights into the factors that shaped the genetic diversity in Greenlanders. Fourteen Greenlandic subsamples from multiple geographical settlements were compared to assess the level of genetic substructure in the Greenlandic population. The results showed low levels of genetic diversity in all sets of the genetic markers studied, together with an increased number of X-chromosomal loci in linkage disequilibrium in relation to the Danish population. In the broader context of worldwide populations, Greenlanders are remarkably different from most populations, but they are genetically closer to some Inuit groups from Alaska. Admixture analyses identified an Inuit component in the Greenlandic population of approximately 80%. The sub-populations of Ammassalik and Nanortalik are the least diverse, presenting the lowest levels of European admixture. Isolation-by-distance analyses showed that only 16% of the genetic substructure of Greenlanders is most likely to be explained by geographic barriers. We suggest that genetic drift and a differentiated settlement history around the island explain most of the genetic substructure of the population in Greenland.

A study of the peopling of Greenland using next generation sequencing of complete mitochondrial genomes

“…Low genetic diversity has previously been found in Ammassalik, both from autosomal, X, and Y chromosomal data (Hallenberg et al, ; Pereira et al, ). Ammassalik is an area that is difficult to access with irregular terrain and high mountains.…”

“…This is contrary to what was observed in the Y‐chromosomal gene pool of Greenland, where 40% of the male lineage was European (Olofsson et al, ). Studies based on X‐chromosomal and autosomal information (Moltke et al, ; Pereira et al, ) supported the observation of a sex‐biased Inuit/European admixture pattern in modern days Greenlanders.…”

“…Previous studies have shown that the admixture pattern is sex‐biased: the male ancestry of Greenlanders is around 60% Inuit and 40% European (Olofsson et al, ), while the female ancestry is mostly Inuit (Gilbert et al, ; Helgason et al, ; Raghavan et al, ). Autosomal admixture analyses and comprehensive SNP investigations showed that the Greenlandic gene pool had around 80% of Inuit and 20% of European components (Moltke et al, ; Pereira et al, ). Moreover, high levels of linkage disequilibrium were detected between markers at the X chromosome (Pereira et al, ).…”

“…Autosomal admixture analyses and comprehensive SNP investigations showed that the Greenlandic gene pool had around 80% of Inuit and 20% of European components (Moltke et al, ; Pereira et al, ). Moreover, high levels of linkage disequilibrium were detected between markers at the X chromosome (Pereira et al, ).…”

High Y‐chromosomal Differentiation Among Ethnic Groups of Dir and Swat Districts, Pakistan

“…Also, investigations of the maternal lineages via mitochondrial genomes should be highly informative, as they may depict a different genetic history if dispersal and gene flow differ between males and females. Such a pattern has been described in geographic areas largely influenced by European settlers such as South America (Roewer et al., ; Fridman et al., ) and Greenland (Pereira et al., ; Helgason et al., ; Olofsson et al., ), and it is likely that the same pattern would be observed among the ethnic groups of Dir and Swat districts given a common preference for patrilateral first‐cousin marriages coupled with postmarital virilocality (Donnan, ; Hussain & Bittles, ; Saadat & Tajbakhsh, ; Saify & Saadat, ; Wahab & Ahmad, ).…”