Mark G. Thomas (born 5 June 1964 on Kingston-upon-Thames, Surrey, England) is a human evolutionary geneticist, Professor of Evolutionary Genetics at the Research Department of Genetics, Evolution and Environment at University College London. He was formerly a researcher in the department of Biological Anthropology at the University of Cambridge.
Thomas is notable for a number of scientific publications in the fields of human demographic and evolutionary history inference, molecular phylogenetics of extinct species using ancient DNA, Cultural evolutionary modelling, and molecular biology. In 1994 Thomas was one of the first people to read the DNA sequence of the extinct woolly mammoth and in 1998 he coauthored a paper providing genetic support to the claim of recent patrilineal common ancestry among the Jewish priestly caste known as Kohanim (singular "Kohen", "Cohen", or Kohane). Between 2000 and 2003 Thomas coauthored several other papers on the origins of various Jewish and Judaic groups, including the Lemba, otherwise known as the "Black Jews of Southern Africa". In 2002 Thomas coauthored a paper providing Y chromosome evidence for a very high Anglo-Saxon component of patrilineal ancestry in central England. This result proved unpalatable for many archaeologists and led to Thomas developing the "apartheid-like social structure" model to explain the discrepancy between archaeological and genetic estimates of the scale of Anglo-Saxon migration.
Thomas has also worked extensively on the evolution of lactase persistence (see Lactose intolerance), the ability of some humans to produce the enzyme lactase throughout their adult life and thus to consume appreciable quantities of fresh milk without the discomforts of lactose malabsorption. In 2004 he led a study to show that most lactase persistent Africans did not have the same mutation causing it as Europeans. In 2007, in collaboration with Joachim Burger's group in Mainz, Germany, he showed that the genetic variant that causes lactase persistence in most Europeans (-13,910*T) was rare or absent in early farmers from central Europe. In 2009 Thomas led a computer simulation study indicating that lactase persistence started to co-evolve with the culture of dairying in the LBK (Linearbandkeramik) culture.
In 2009 - in collaboration with Prof Stephen Shennan and Dr Adam Powell - Thomas published a study in the journal Science showing that population density and or migratory activity are likely to be a major determinants in the maintenance or loss of culturally inherited skills, and that this seemed to explain a number of curious features of the appearance of behavioural modernity in humans at different times in different parts of the world.
Selected scientific publications
- Hagelberg E, Thomas MG, Cook Jr CE, Sher AV, Baryshnikov GF, Lister AM. 1994. DNA from ancient mammoth bones. Nature 370:333-334.
- Thomas, MG; Skorecki K, Ben-Ami H, Parfitt T, Bradman N, Goldstein DB (1998). "Origins of Old Testament priests". Nature 394: 138-40. doi:10.1038/28083. PMID 9671297.
- Thomas, M. G., Hagelberg, E., Jone, H. B., Yang, Z. & Lister, A. M. 2000a Molecular and morphological evidence on the phylogeny of the Elephantidae. Proc R Soc Lond B Biol Sci 267, 2493-500.
- Thomas, M. G., Parfitt, T., Weiss, D. A., Skorecki, K., Wilson, J. F., le Roux, M., Bradman, N. & Goldstein, D. B. 2000b Y Chromosomes Traveling South: The Cohen Modal Haplotype and the Origins of the Lemba--the "Black Jews of Southern Africa". Am J Hum Genet 66, 674-86.
- Thomas, M. G., Stumpf, M. P. & Harke, H. 2006 Evidence for an apartheid-like social structure in early Anglo-Saxon England. Proc Biol Sci 273, 2651-7.
- J. Burger, M. Kirchner, B. Bramanti, W. Haak, M. G. Thomas (2007) Absence of the Lactase-Persistence associated allele in early Neolithic Europeans. Proceedings of the National Academy of Sciences USA 104: pp3736-3741.
- Yuval Itan, Adam Powell, Mark A. Beaumont, Joachim Burger and Mark G. Thomas (2009) The Origins of Lactase Persistence in Europe. PLoS Comput Biol 5(8): e1000491.
- Powell, A., Shennan, S., and Thomas, M.G. (2009) Late Pleistocene Demography and the Appearance of Modern Human Behavior. Science 324: pp 1298 - 1301.
- B. Bramanti, M. G. Thomas, W. Haak, M. Unterlaender, P. Jores, K. Tambets, I. Antanaitis-Jacobs, M. N. Haidle, R. Jankauskas, C.-J. Kind, F. Lueth, T. Terberger, J. Hiller,9§ S. Matsumura, P. Forster, J. Burger (2009) Genetic Discontinuity Between Local Hunter Gatherers and Central Europe's First Farmers. Science 326: pp 137 - 140.
- Helena Malmström, M.Thomas P. Gilbert, Mark G. Thomas, Mikael Brandström, Jan Storå, Petra Molnar, Pernille K. Andersen, Christian Bendixen, Gunilla Holmlund, Anders Götherström, and Eske Willerslev (2009) Ancient DNA Reveals Lack of Continuity between Neolithic Hunter-Gatherers and Contemporary Scandinavians. Current Biology 19, pp 1-5.
- ^ Prof Mark Thomas Archived 2010-09-29 at the Wayback Machine., UCL School of Life and Medical Sciences
- ^ Hagelberg et al., 1994; Thomas et al., 2000a
- ^ Thomas et al., 2000b.
- ^ Weale et al., 2002.
- ^ Thomas et al., 2006
- ^ Charlotte A. Mulcare, Michael E. Weale, Abigail L . Jones, Bruce Connell, David Zeitlin, Ayele Tarekegn, Dallas M. Swallow, Neil Bradman and Mark G. Thomas (2004) The T allele located 13.9 kb upstream of the lactase gene (LCT) (C-13.9kbT) does not predict or cause the lactase persistence phenotype in Africans. American Journal of Human Genetics 74: pp1102-1110.
- ^ J. Burger, M. Kirchner, B. Bramanti, W. Haak, M. G. Thomas (2007) Absence of the Lactase-Persistence associated allele in early Neolithic Europeans Archived 2008-10-31 at Archive-It. Proceedings of the National Academy of Sciences USA 104: pp3736-3741.
- ^ Yuval Itan, Adam Powell, Mark A. Beaumont, Joachim Burger and Mark G. Thomas (2009) The Origins of Lactase Persistence in Europe. PLoS Comput Biol 5(8): e1000491.
- ^ Powell, A., Shennan, S., and Thomas, M.G. (2009) Late Pleistocene Demography and the Appearance of Modern Human Behavior. Science 324: pp. 1298-1301 
- ^ Blood and Treasure, The Economist, Jun 4th 2009