Genetics: Ancient DNA sheds light on Britain's history of migration

New analyses of the ancient DNA of British individuals help disentangle the impact of migration events from continental Europe into Britain before and after the Anglo-Saxon invasion (circa fifth century AD). The results are described in two separate papers published in Nature Communications.

Past genetics studies based on modern genomes have resulted in mixed opinions about the migratory history of people in and out of the British Isles. The recent refinement of techniques that allow the extraction of ancient genetic information can provide insight into the major migration events in human history.

In one paper, Daniel Bradley and colleagues sequence the DNA of nine individuals from north Britain, including seven individuals from a Roman era (late BC/early AD) cemetery in York, one from an earlier Iron Age burial and one from a later Anglo-Saxon burial. They find that the whole genomes of Roman-era individuals from northern Britain are similar to the modern British Celtic population and to the earlier Iron Age genomes, but differ significantly from modern day Yorkshire genomes or Anglo-Saxon genomes. The authors show that all Roman-era individuals except one were indigenous Britons in terms of their genomic signal. A single Roman individual possessed high genetic similarity to modern day Middle Eastern and North African populations, suggesting movement of people from very distant areas was taking place within the Roman Empire.

In the other paper, Stephan Schiffels and colleagues sequence the genome of ten individuals dating back to the Iron Age and the Anglo-Saxon period, from cemeteries in east England, close to Cambridge. They use present-day genetic data to characterize the relationship of these ancient individuals to contemporary British and other European populations. They show that the contemporary population in eastern England derives approximately 30% of its ancestry from Anglo-Saxon migrations, with a lower percentage in Welsh and Scottish individuals, and find that Anglo-Saxon samples share more genetic similarities with modern Dutch and Danish populations than with Iron Age samples.