<P> Research published in 2003 on Y - chromosome marker variation, taken from a larger sample population and from more sites throughout Britain, came to a different conclusion . This study suggested that in most of England, continental (North German and Danish) paternal genetic input varied between 20% and 40%, with York forming an outlier at about 60% . Southern England, including Kent, had markedly lower frequencies of non-indigenous Y - chromosome markers than eastern England, where Danish Viking settlement is attested . However, the study could not distinguish between North German and Danish populations, thus the relative proportions of genetic input derived from the Anglo - Saxon settlements and later Danish Viking colonisation could not be ascertained . </P> <P> Historical evidence suggests that following the Anglo - Saxon transition, people of indigenous ethnicity were at an economic and legal disadvantage compared to those having Anglo - Saxon ethnicity . This has led to the development of the "apartheid - like social structure" theory to explain this high contribution to the modern gene pool, where the proportion of settlers would be smaller . </P> <P> This view has been challenged by JE Pattison, who suggested that the Y - chromosome evidence could still support the idea of a small settlement of people without the apartheid - like structures . In addition, there is no reliable method for dating the influx of genetic material into Britain from the Continent; and the genetic similarities between people on either side of the North Sea may reflect a cumulative process of population movement, possibly beginning well before the historically attested formation of the Anglo - Saxons or the invasions of the Vikings . The' apartheid theory' has received a considerable body of critical comment, especially the genetic studies from which it derives its rationale . Problems with the design of Weale's study and the level of historical naivete evidenced by some population genetics studies have been particularly highlighted . </P> <P> Stephen Oppenheimer reviewed the Weale and Capelli studies and suggested that correlations of gene frequency mean nothing without a knowledge of the genetic prehistory of the regions in question . His criticism of these studies is that they generated models based on the historical evidence of Gildas and Procopius, and then selected methodologies to test against these populations . Weale's transect spotlights that Belgium is further west in the genetic map than North Walsham, Asbourne and Friesland . In Oppenheimer's view, this is evidence that the Belgae and other continental people--and hence continental genetic markers indistinguishable from those ascribed to Anglo - Saxons--arrived earlier and were already strong in the 5th century in particular regions or areas . Oppenheimer, basing his research on the Weale and Capelli studies, maintains that none of the invasions since the Romans have had a significant impact on the gene pool of the British Isles, and that the inhabitants from prehistoric times belong to an Iberian genetic grouping . He says that most people in the British Isles are genetically similar to the Basque people of northern Spain and southwestern France, from 90% in Wales to 66% in East Anglia . Oppenheimer suggests that the division between the West and the East of England is not due to the Anglo - Saxon invasion but originates with two main routes of genetic flow--one up the Atlantic coast, the other from neighbouring areas of Continental Europe--which occurred just after the Last Glacial Maximum . Bryan Sykes, a former geneticist at Oxford University, came to fairly similar conclusions as Oppenheimer, which he set forth in his 2006 book called Blood of the Isles: Exploring the Genetic Roots of our Tribal History, published in the United States and Canada as Saxons, Vikings and Celts: The Genetic Roots of Britain and Ireland . Many feasible scenarios can be constructed to account for evidence . However, Y - chromosome evidence relies on the archaeological and historical evidence for interpretation, and there is a danger of creating a circular argument . Therefore, scenarios that are not justified by other evidence or are created to account for the historical evidence have not been universally accepted . </P>

Where did the anglo saxons settled in britain