Uncovering the Genetic History of the Present-Day Greenlandic Population

Ida Moltke,Matteo Fumagalli,Thorfinn S Korneliussen,Jacob E Crawford,Peter Bjerregaard,Marit E Jørgensen,Niels Grarup,Hans Christian Gulløv,Allan Linneberg,Oluf Pedersen,Torben Hansen,Rasmus Nielsen,Anders Albrechtsen

doi:10.1016/j.ajhg.2014.11.012

Abstract

Because of past limitations in samples and genotyping technologies, important questions about the history of the present-day Greenlandic population remain unanswered. In an effort to answer these questions and in general investigate the genetic history of the Greenlandic population, we analyzed ∼200,000 SNPs from more than 10% of the adult Greenlandic population (n = 4,674). We found that recent gene flow from Europe has had a substantial impact on the population: more than 80% of the Greenlanders have some European ancestry (on average ∼25% of their genome). However, we also found that the amount of recent European gene flow varies across Greenland and is far smaller in the more historically isolated areas in the north and east and in the small villages in the south. Furthermore, we found that there is substantial population structure in the Inuit genetic component of the Greenlanders and that individuals from the east, west, and north can be distinguished from each other. Moreover, the genetic differences in the Inuit ancestry are consistent with a single colonization wave of the island from north to west to south to east. Although it has been speculated that there has been historical admixture between the Norse Vikings who lived in Greenland for a limited period ∼600–1,000 years ago and the Inuit, we found no evidence supporting this hypothesis. Similarly, we found no evidence supporting a previously hypothesized admixture event between the Inuit in East Greenland and the Dorset people, who lived in Greenland before the Inuit.

Highlights

With its more than 2,150,000 km[2], Greenland is the largest island in the world
To investigate the genetic history of the present-day Greenlandic population, we analyzed genetic data from 4,127 Greenlandic individuals from 15 different locations in Greenland (Figure 1), 547 Greenlandic individuals living in Denmark, 50 Danish individuals, and 208 unrelated individuals from the original HapMap project
The Danish individuals were included to represent the European ancestors of the Greenlanders, which are mainly from Denmark and Norway, and the HapMap individuals were included for comparison to other populations from the rest of the world

Summary

Introduction

With its more than 2,150,000 km[2], Greenland is the largest island in the world. because of its cold climate and remote location, it has historically been only sparsely populated, and the size of its present-day population is only about 57,000 individuals.Archeological evidence indicates that Greenland was colonized several times when people from northeastern Canada entered into the northwestern part of the island.[1]. Archaeology has provided substantial evidence of contact between Norse, Late Dorset, and Inuit pioneers.[2,3] These interactions did not necessarily take place close to the Norse settlements but could have taken place anywhere in West Greenland.[2] From the 14th century onward, the Inuit settled in West and Southeast Greenland They traveled north around the country and settled in Northeast Greenland for four centuries, and several archeological studies have suggested that a gradual migration south into Southeast Greenland originated there.[4,5] In the 17th century, the Inughuit Polar Eskimos (new Inuit people from the central Canadian Arctic) settled in the Thule district. In 1721, the Norwegian priest Hans Egede initiated a period during which Greenland was a Danish colony, which lasted until 1953 and ended formally in 1979, when Denmark granted home rule to Greenland

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Results

Conclusion