Y Chromosome Evidence for Anglo-Saxon Mass Migration

Abstract

British history contains several periods of major cultural change. It remains controversial as to how much these periods coincided with substantial immigration from continental Europe, even for those that occurred most recently. In this study, we examine genetic data for evidence of male immigration at particular times into Central England and North Wales. To do this, we used 12 biallelic polymorphisms and six microsatellite markers to define high-resolution Y chromosome haplotypes in a sample of 313 males from seven towns located along an east-west transect from East Anglia to North Wales. The Central English towns were genetically very similar, whereas the two North Welsh towns differed significantly both from each other and from the Central English towns. When we compared our data with an additional 177 samples collected in Friesland and Norway, we found that the Central English and Frisian samples were statistically indistinguishable. Using novel population genetic models that incorporate both mass migration and continuous gene flow, we conclude that these striking patterns are best explained by a substantial migration of Anglo-Saxon Y chromosomes into Central England (contributing 50%-100% to the gene pool at that time) but not into North Wales.

The scale and nature of Viking settlement in Ireland from Y-chromosome admixture analysis

“…We also conducted additional admixture analysis with these methods using independent parental populations data sets including a larger Irish grouping (n ¼ 221) 11 and separate Norwegian (n ¼ 250), 6,30,31 Danish (n ¼ 69) 6,32 or Swedish (n ¼ 110) 30 populations. To allow comparability between data sets, this analysis was based on five STR haplotypes (DYS19, DYS390, DYS391, DYS392 and DYS393).…”

The C9ORF72 expansion mutation is a common cause of ALS+/−FTD in Europe and has a single founder

“…We assumed that a random population sample of 39 091 would be expected to yield 137 HREMbearing individuals, based on our observed frequency of 3 in 856 controls, and we assumed that such a sample would form a fraction of 7.8 Â 10 À5 of all Europeans, based on a current population size of 500 million. We performed DMLE þ using a burn-in of 20 000 iterations followed by runs of 100 000 iterations, with population growth rates in Europe of 5%, 20 with a lower limit of 2.5% 21 and an upper limit of 8.5%, 22 and with a 25-year inter-generation time, with lower and upper limits of 20 and 30 years respectively.…”

New genetic evidence supports isolation and drift in the Ladin communities of the South Tyrolean Alps but not an ancient origin in the Middle East

“…Locus-specific priors for the mutation rate per generation were based on observed mutations. 34 These were: DYS19 -Gamma(3,1459), DYS390 -Gamma(5,929), DYS391 -Gamma(3,878), DYS392 -Gamma(2,878), and DYS393 -Gamma(1,878). As a precautionary measure, DYS388 was excluded from BATWING analysis because no published data on observed meioses are available for this locus.…”

“…33 We ran 102 000 Monte Carlo iterations of the coalescent simulation and discarded the first 2000 iterations as burn-in. Population demographic priors were: initial effective population size -gamma(1.1,0.0001), growth rate -gamma(1.01,1), time growth starts (in generations) -uniform(0, time to most recent common ancestor), 34 final population size -uniform(0, 50 000). Locus-specific priors for the mutation rate per generation were based on observed mutations.…”