人類学：英国人の祖先を調べる

Mass migration into Britain across the North Sea from Germany, The Netherlands and Denmark during the Anglo-Saxon period may have increased European ancestry up to 76% in Britain, reports a Nature paper. The findings suggest that migrations from continental Europe influenced the formation of early medieval British society.

The history of the British Isles and Ireland is characterized by periods of major cultural change — such as after the Roman era — that led to shifts in, for example, language, settlement patterns, manufacture, architecture and agriculture. However, understanding the extent to which human migration from continental Europe mediated these cultural transitions remains challenging. Previous genome-wide studies have focussed on present-day British people to assess ancestry, but these may not be representative of ancient groups with unknown genetic makeup.

To examine contemporary British population dynamics, Stephan Schiffels, Duncan Sayer and colleagues studied archaeological data and genome-wide ancient DNA from 460 medieval individuals — dated between 200 and 1300 CE — across northwestern Europe, including 278 individuals from England. They identified an increase in continental northern European ancestry in early medieval England, which was closely related to the early medieval and current inhabitants of Germany and Denmark. The individuals analysed from eastern England were found to derive up to 76% of their ancestry from the continental North Sea zone. Subsequent demographic events were found to reduce the proportion of continental northern European ancestry and to introduce new components such as southwestern European ancestry, similar to that found in Iron Age France. Additionally, they found that women with immigrant ancestry were more likely to be buried with grave goods, such as brooches, than women with local ancestry. Whereas men with weapons were just as likely to be native or of immigrant ancestry.

The authors suggest that in present-day Britain, a substantial northern continental ancestry remains, albeit at a lower level than during the early medieval period, indicating a lasting demographic impact of the ‘Anglo-Saxon’ migrations.