4.2. Tracing populations with Haplogroups
Transcription
4.2. Tracing populations with Haplogroups
4.2. Tracing populations with Haplogroups The definition of a haplogroup is the group of all the paternal descendants of the single person who first showed that SNP mutation. Example for mutation creating Y Haplogroup I1, which characterizes Scandinavian populations. Y-chromosome DNA X-Y inheritance, females carry XX chromosome pair, males carry XY chromosome pair. Females get X from mother and the X from father. Males get x from mother and Y from father. Y-chromosome is exclusively passed on along male line from father to son! Y Haplogroups A BT B CT CF DE C F D E G H IJK IJ K I J L M NO P S T N O Q R Neolithic Farmers Y Haplogroups E1b1b (yellow) (formerly 3b) and G (green) are common among Neolithic farmers from the Middle East who brought agriculture into Europe about 9000 years ago. The date of the most recent ancestor of E3b haplogroups is estimated to 24-27 thousand years ago. The most likely origin is eastern Africa. Haplogroup G originates in Iran, Caucasus region, 60% in North Ossetians, 30% in Georgians Bantu Migration Bantu migration was reflected in the spread of iron smelting techniques from West-Africa to East- and South-Africa Confirmed by genetic tracing of haplogroup E1a1b (formerly E3a). The Haplogroup R1 From Western Europe to Central Asia Reflection of the Tarim Mummies? R1b red R1a purple Origin of R about 30,000 years ago ! Distributed by ice age and resettlement The Mitochondrial Eve When sperm and ovum fuse nuclear DNA is distributed in equal amounts. Mitochondrial DNA is only passed on by ovum, from mother to daughter. The development of new Eve’s Chronological development of mtDNA haplogroups U => 50,000 to 60,000 years ago (arose in Western Asia) H => 30,000 to 50,000 years ago (in the Near East - associated with Cro-Magnon in Europe) J => 45,000 years ago (in the Near East) X => over 30,000 years ago (in Caucasus) (Neanderthal???) I => 30,000 years ago (origin unknown - probably in Europe) W => 25,000 years ago (in north-east Europe or north-west Asia) K => 15,000 years ago (in the Near East) (Oetzi) T => 10,000 years ago (in Mesopotamia) V => 10,000 years ago (arose in Iberia and moved to Scandinavia) Mitochondrial Haplogroups mitochondrial DNA haplogroup is defined by differences in human mitochondrial DNA. This allows to trace the matrilineal inheritance of modern humans back to human origins in Africa and the spread across the globe. Out of Africa, again Brother Neanderthal Or that? Where they like this? Gen sequence from bone material Molecular analysis of Neanderthal DNA from the northern Caucasus; I. V. Ovchinnikov, A. Götherström, G. P. Romanova, V. M. Kharitonov, K.Lidén and W. Goodwin; Nature 404, 490(2000) Separation and Difference Distinct differences in human genetic structure compared to Neanderthal and Chimpanzee. Human red Neanderthal blue Analysis of one million base pairs of Neanderthal DNA R. E. Green, J. Krause, S. E. Ptak, A. W. Briggs, M. T. Ronan, J. F. Simons, L. Du, M. Egholm, J. M. Rothberg, M.Paunovic & S. Pääbo; Nature 444, 330 (206) Is there indication for genetic linkage? Based on lack of identification of any Neanderthal genes in human DNA and on results of theoretical population models the maximum initial input of Neanderthal genes into the Paleolithic European gene pool has been estimated to lie between 0.02% and 0.09%. Population genetics simulation showing the percentage of Neanderthal genes (red) of the total number of genes in European population if free interbreeding would have occurred in areas of contact. Modern Humans Did Not Admix with Neanderthals during Their Range Expansion into Europe M. Currat and L. Excoffier; PLoS Biol 2(12): e421 doi:10.1371/journal.pbio.0020421 The last resort