Mark G. Thomas
Encyclopedia
Mark G. Thomas is a human evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

ary geneticist
Geneticist
A geneticist is a biologist who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a researcher or lecturer. Some geneticists perform experiments and analyze data to interpret the inheritance of skills. A geneticist is also a Consultant or...

, Professor of Evolutionary Genetics at the Research Department of Genetics, Evolution and Environment at University College London
University College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...

. He was formerly a researcher in the department of Biological Anthropology
Biological anthropology
Biological anthropology is that branch of anthropology that studies the physical development of the human species. It plays an important part in paleoanthropology and in forensic anthropology...

 at the University of Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...

.

Scientific Career

Thomas is notable for a number of scientific publications in the fields of human demographic and evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

ary history inference, molecular phylogenetics of extinct species
Extinct species
This page features extinct species, organisms that have become extinct.* List of extinct animals* List of extinct plants...

 using ancient DNA
Ancient DNA
Ancient DNA is DNA isolated from ancient specimens. It can be also loosely described as any DNA recovered from biological samples that have not been preserved specifically for later DNA analyses...

, Cultural evolutionary modelling, and molecular biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

. In 1994 Thomas was one of the first people to read the DNA sequence of the extinct woolly Mammoth (Hagelberg et al., 1994; Thomas et al., 2000a) and in 1998 he coauthored a paper providing genetic
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

 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
Lemba
The Lemba or 'wa-Remba' are a southern African ethnic group to be found in Zimbabwe and South Africa with some little known branches in Mozambique and Malawi. According to Parfitt they are thought to number 70,000...

, otherwise known as the "Black Jews of Southern Africa" (Thomas et al., 2000b). In 2002 Thomas coauthored a paper providing Y chromosome
Y chromosome
The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...

 evidence for a very high Anglo-Saxon
Anglo-Saxon
Anglo-Saxon may refer to:* Anglo-Saxons, a group that invaded Britain** Old English, their language** Anglo-Saxon England, their history, one of various ships* White Anglo-Saxon Protestant, an ethnicity* Anglo-Saxon economy, modern macroeconomic term...

 component of patrilineal ancestry in central England (Weale et al., 2002) Settlement of Great Britain and Ireland
Settlement of Great Britain and Ireland
The British Isles have experienced a long history of migration from across Europe. Over the millennia, successive waves of immigrants have come to the Isles, a process that is continuing today. The ancient migrations have mainly come via two routes: along the Atlantic coast and from...

. This result proved unpalatable for many archaeologists and led to Thomas developing the "apartheid-like social structure" model (Thomas et al., 2006) 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
Lactose intolerance
Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk...

), the ability of some humans to produce the enzyme lactase
Lactase
Lactase , a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers...

 throughout their adult life and thus to consume appreciable quantities of fresh milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

 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 (Mulcare et al. 2004). In 2007, in collaboration with Joachim Burger
Joachim Burger
Professor Dr Joachim Burger is a German anthropologist and molecular biologist based at Johannes Gutenberg University, Mainz, Germany, where he runs the at the .- Scientific career :...

'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 (Burger et al. 2007) ). 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 (Itan et al., 2009).

In 2009 – in collaboration with Prof Stenphen 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 (Powell et al., 2009, also see article in The Economist ).

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., http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1288118.

  • 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 Science 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.

See also

  • Y-chromosomal Aaron
    Y-chromosomal Aaron
    Y-chromosomal Aaron is the name given to the hypothesised most recent common ancestor of many of the patrilineal Jewish priestly caste known as Kohanim . In the Torah, this ancestor is identified as Aaron, the brother of Moses...

  • Lemba
    Lemba
    The Lemba or 'wa-Remba' are a southern African ethnic group to be found in Zimbabwe and South Africa with some little known branches in Mozambique and Malawi. According to Parfitt they are thought to number 70,000...

  • Settlement of Great Britain and Ireland
    Settlement of Great Britain and Ireland
    The British Isles have experienced a long history of migration from across Europe. Over the millennia, successive waves of immigrants have come to the Isles, a process that is continuing today. The ancient migrations have mainly come via two routes: along the Atlantic coast and from...

  • lactase
    Lactase
    Lactase , a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers...

  • lactase persistence
    Lactase persistence
    Lactase persistence is the continued activity of the enzyme lactase in adulthood. Since lactase's only function is the digestion of lactose in milk, in most mammalian species the activity of the enzyme is dramatically reduced after weaning...

  • behavioural modernity

External links

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