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The CECD is an AHRC funded research group dedicated to examining the evolutionary underpinnings of human cultural behaviour, past and present. more>

Page Title - projects
Phase 2: Theme A - Demographic processes and cultural change: Project A005
Population replacement in Anglo-Saxon England


Mark Thomas (Research Department of Genetics, Evolution and Environment, University College London)

PROJECT FUNDING: Cards Against Humanity
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The role of migration in the Anglo-Saxon transition in England remains controversial. Archaeological and historical evidence is inconclusive but current estimates of the contribution of migrants to the English population range from less than 10,000 to as many as 200,000 (Hills, 2003). In contrast, recent studies based on Y chromosome variation (Weale et al., 2002; Capelli et al., 2003) posit a considerably higher contribution to the modern English gene pool (50 to 100%). 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. It is likely that such a disadvantage would lead to differential reproductive success. Computer simulations of this Apartheid-like social structure indicate that a limiting intermarriage between indigenous Britons and an initially small Anglo-Saxon immigrant population provides a plausible explanation of the high degree of Continental male-line ancestry in England (Thomas et al., under review). In this project, new population samples from different regions of Britain will continue to be typed for Y chromosome variation and current simulations will be extended to include a demic component (Currat et al., 2005). The overall aim of this project is to form a deeper understanding of the spread of Anglo-Saxon culture and the genetic variants associated with the initial migration, in Britain under a range of migrational and social structure parameters. Simulation outcomes will be compared to modern data of the distribution of Y chromosome variants, and historical data on the spread of the English language in Britain.


Weale, M. E., Weiss, D. A., Jager, R. F., Bradman, N. & Thomas, M. G. 2002 Y chromosome evidence for Anglo-Saxon mass migration. Mol Biol Evol 19, 1008-21.

Capelli, C., Redhead, N., Abernethy, J. K., Gratrix, F., Wilson, J. F., Moen, T., Hervig, T., Richards, M., Stumpf, M. P., Underhill, P. A., Bradshaw, P., Shaha, A., Thomas, M. G., Bradman, N. & Goldstein, D. B. 2003 A Y chromosome census of the British Isles. Curr Biol 13, 979-84.

Currat, M. & Excoffier, L. 2005 The effect of the Neolithic expansion on European molecular diversity. Proc Biol Sci 272, 679-88.

Hills, C. 2003 Origins of the English. Duckworth debates in archaeology. London: Duckworth.

Thomas, M.G., Stumpf, M. P. H. and Härke, H. (manuscript submitted) Evidence for an Apartheid-like social structure in early Anglo-Saxon England.

Project Suspended

Fletcher, D. C., Härke, H., and Thomas, M. G (in press).
Estimating demographic parameters in Early Anglo-Saxon England.
Thomas, M. G., Härke, H., German, G. & Stumpf, M. P. H (2008).
Integration versus Apartheid In Post-Roman Britain: A Response To Pattison . Proceedings of the Royal Society B: Biological sciences. Vol 275:2419-2421.
Thomas, M. G., Härke, H., German, G. & Stumpf, M. P. H (2008).
Social constraints on interethnic marriage/unions, differential reproductive success and the spread of ‘Continental’ Y chromosomes in early Anglo-Saxon England. In: S. Matsumura, P. Forster & C. Renfrew (eds.) (ed\s) Simulations, Genetics and Human Prehistory. Cambridge: McDonald Institute for Archaeological Research. 59-68.