Research undertaken by Professor Einar Árnason at the University of Iceland, Reykjavik and published in the January 2003 issue of Annals of Human Genetics highlights the inaccuracy of claims that Icelanders are a ’genetically homogenous’ population.
Professor Árnason explains in his article: "Recently, statements have been made about a special ’genetic homogeneity’ of the Icelanders that are at variance with earlier work on blood groups and allozymes." Iceland has been said to be an "island so inbred that it is a happy genetic hunting ground", ideal for gene mapping, and that "nowhere else has such a pure – and predictable – genetic inheritance" in the popular press. This supposed genetic homogeneity was a major factor in the establishment of deCODE Genetics, the biotechnology company set up in Iceland in 1996 to map disease genes in the Icelandic population. The geographical isolation of the country with little migration for over 1000 years, combined with a series of disasters such as plague and famine, was presumed to have minimized variation in the gene pool. Researchers now suggest that there was a lack of evidence to confirm this homogeneity.
To investigate these claims an extensive reanalysis of mtDNA variation was undertaken by examining primary data from original sources for 26 European populations. The results showed that Icelanders are actually among the most genetically heterogeneous Europeans by the mean number of nucleotide differences, as well as by estimates of parameters of the neutral theory. This is a signature of population admixture during the founding or history of Iceland. Examination of the published literature on blood group and allozyme variation did not provide any support for the notion of special genetic homogeneity of the Icelanders, and further studies of microsatellite variation are unlikely to do so. It is doubtful that population changes during past calamities had much effect on the genetic variability of Icelanders.
Professor Einar Árnason | EurekAlert!
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