Mitochondrial DNA Haplogroup U5 - News

Good article from Dienekes on ancient DNA in Europe and links to Asia:

http://dienekes.blogspot.com/2009/09/some-mtdna-links-between-europe-and.html


Recent research papers on Haplogroup U5:

"Genetic Diversity among Ancient Nordic Populations", L Melchior, N Lynnerup, HR Siegismund, T Kivisild, and J Dissing, PLoS One, January 1, 2010; 5(7): e11898.

Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13%) than among extant Danes and Scandinavians ( approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.



"Genetic Discontinuity Between Local Hunter-Gatherers and Central Europe’s First Farmers", published in 2009 by B. Bramanti et al.
Abstract
After the domestication of animals and crops in the Near East some 11,000 years ago, farming had reached much of central Europe by 7500 years before the present. The extent to which these early European farmers were immigrants or descendants of resident hunter-gatherers who had adopted farming has been widely debated. We compared new mitochondrial DNA (mtDNA) sequences from late European hunter-gatherer skeletons with those from early farmers and from modern Europeans. We find large genetic differences between all three groups that cannot be explained by population continuity alone. Most (82%) of the ancient hunter-gatherers share mtDNA types that are relatively rare in central Europeans today. Together, these analyses provide persuasive evidence that the first farmers were not the descendants of local hunter-gatherers but immigrated into central Europe at the onset of the Neolithic. Supplemental data can be downloaded at:
http://www.sciencemag.org/cgi/content/full/1176869/DC1
Also see Dienekes blog on this study:
http://dienekes.blogspot.com/2009/09/central-european-farmers-not-descended.html

Correcting for Purifying Selection: An Improved Human Mitochondrial Molecular Clock, Soares et al., 2009.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2694979/
This is comprehensive but very technical paper. It includes age estimates for U5 and it daughter groups.
Excerpt:
Europe was first settled by modern humans ∼45 kya, and it is believed that one of the branches of U, U5 or a genetically close ancestor to U5, arose among the first settlers. The ML estimate of haplogroup U5 is 36.0 (25.3 to 47.2) kya, and lower with ρ at 30.7 (21.4 to 40.5) kya and 33.0 (13.3 to 52.8) with our synonymous rate. The evidence suggests that the earliest branching within U5 in Europe was lost by drift or is only present in the population at very low frequencies. The closest link in the tree with the Near East is the root of haplogroup U, placing any early migration into Europe involving U5 or its ancestors between ∼55 kya and ∼30 kya.


The Peopling of Europe from the Mitochondrial Haplogroup U5 Perspective, Malyarchuck et al, 2010
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010285
Supplemental data including revised trees for U5a and U5b can be downloaded at the above link.
Abstract
It is generally accepted that the most ancient European mitochondrial haplogroup, U5, has evolved essentially in Europe. To resolve the phylogeny of this haplogroup, we completely sequenced 113 mitochondrial genomes (79 U5a and 34 U5b) of central and eastern Europeans (Czechs, Slovaks, Poles, Russians and Belorussians), and reconstructed a detailed phylogenetic tree, that incorporates previously published data. Molecular dating suggests that the coalescence time estimate for the U5 is ~25–30 thousand years (ky), and ~16–20 and ~20–24 ky for its subhaplogroups U5a and U5b, respectively. Phylogeographic analysis reveals that expansions of U5 subclusters started earlier in central and southern Europe, than in eastern Europe.