In Search of Geographical Patterns in European Mitochondrial DNA
Previous studies of mitochondrial DNA (mtDNA) in Europe and the Near East have suggested that, in contrast with classical markers and the Y chromosome, mtDNA does not exhibit significant geographical structuring. Here, we show that, with a sufficiently large sample size and a better resolved mtDNA tree, clades of mtDNA do indeed exhibit gradients similar to those of other marker systems. However, the more detailed analyses afforded by molecular sequence data suggest that the explanations for these gradients are likely to be much more complex than those proposed for classical markers.
PDF file
Complex Signals for Population Expansions in Europe and Beyond
PDF file
The molecular genetics of European ancestry
In an earlier paper we proposed, on the basis of mitochondrial control region variation, that the bulk of modern European mitochondrial DNA(mtDNA) diversity had its roots in the European Upper Palaeolithic. Refining the mtDNA phylogeny and enlarging the sample size both within Europe and the Middle East still support this interpretation and indicate three separate phases of colonization: (i) the Early Upper Palaeolithic about 50,000 BP; (ii) the Late Upper Palaeolithic 11,000-14,000 BP; and (iii) the Neolithic from 8500 BP.
PDF file
Mitochondrial DNA and IQ in Europe
Recently a mitochondrial DNA polymorphism (EST00083) was found at significantly different frequencies in high IQ and low IQ groups in two independent studies. We have used mitochondrial sequences from a range of populations to show that this polymorphism occurred more than once in human history. Furthermore, the polymorphism is particularly common in Europe where it is predominantly associated with a single mitochondrial line (lineage) that appears to date back to the expansion of anatomically modern humans into Europe about 35,000 years ago. Examination of the genetic diversity within this mitochondrial lineage, together with the known migration and settlement of Europeans into the USA, suggests that the observed IQ associated polymorphism found in Cleveland Ohio is likely to be restricted to only one form (sub-group) of this mitochondrial lineage.
PDF file
A Signal, from Human mtDNA, of Postglacial Recolonization in Europe
Mitochondrial HVS-I sequences from 10,365 subjects belonging to 56 populations/geographical regions of western Eurasia and northern Africa were first surveyed for the presence of the T->C transition at nucleotide position 16298, a mutation which has previously been shown to characterize haplogroup V mtDNAs. All mtDNAs with this mutation were then screened for a number of diagnostic RFLP sites, revealing two major subsets of mtDNAs. One is haplogroup V proper, and the other has been termed “pre*V,” since it predates V phylogenetically. The rather uncommon pre*V tends to be scattered throughout Europe (and northwestern Africa), whereas V attains two peaks of frequency: one situated in southwestern Europe and one in the Saami of northern Scandinavia. Geographical distributions and ages support the scenario that pre*V originated in Europe before the Last Glacial Maximum (LGM), whereas the more recently derived haplogroup V arose in a southwestern European refugium soon after the LGM. The arrival of V in eastern/central Europe, however, occurred much later, possibly with (post-)Neolithic contacts. The distribution of haplogroup V mtDNAs in modern European populations would thus, at least in part, reflect the pattern of postglacial human recolonization from that refugium, affecting even the Saami. Overall, the present study shows that the dissection of mtDNA variation into small and well-defined evolutionary units is an essential step in the identification of spatial frequency patterns. Mass screening of a few markers identified using complete mtDNA sequences promises to be an efficient strategy for inferring features of human prehistory.
PDF file
Previous studies of mitochondrial DNA (mtDNA) in Europe and the Near East have suggested that, in contrast with classical markers and the Y chromosome, mtDNA does not exhibit significant geographical structuring. Here, we show that, with a sufficiently large sample size and a better resolved mtDNA tree, clades of mtDNA do indeed exhibit gradients similar to those of other marker systems. However, the more detailed analyses afforded by molecular sequence data suggest that the explanations for these gradients are likely to be much more complex than those proposed for classical markers.
PDF file
Complex Signals for Population Expansions in Europe and Beyond
PDF file
The molecular genetics of European ancestry
In an earlier paper we proposed, on the basis of mitochondrial control region variation, that the bulk of modern European mitochondrial DNA(mtDNA) diversity had its roots in the European Upper Palaeolithic. Refining the mtDNA phylogeny and enlarging the sample size both within Europe and the Middle East still support this interpretation and indicate three separate phases of colonization: (i) the Early Upper Palaeolithic about 50,000 BP; (ii) the Late Upper Palaeolithic 11,000-14,000 BP; and (iii) the Neolithic from 8500 BP.
PDF file
Mitochondrial DNA and IQ in Europe
Recently a mitochondrial DNA polymorphism (EST00083) was found at significantly different frequencies in high IQ and low IQ groups in two independent studies. We have used mitochondrial sequences from a range of populations to show that this polymorphism occurred more than once in human history. Furthermore, the polymorphism is particularly common in Europe where it is predominantly associated with a single mitochondrial line (lineage) that appears to date back to the expansion of anatomically modern humans into Europe about 35,000 years ago. Examination of the genetic diversity within this mitochondrial lineage, together with the known migration and settlement of Europeans into the USA, suggests that the observed IQ associated polymorphism found in Cleveland Ohio is likely to be restricted to only one form (sub-group) of this mitochondrial lineage.
PDF file
A Signal, from Human mtDNA, of Postglacial Recolonization in Europe
Mitochondrial HVS-I sequences from 10,365 subjects belonging to 56 populations/geographical regions of western Eurasia and northern Africa were first surveyed for the presence of the T->C transition at nucleotide position 16298, a mutation which has previously been shown to characterize haplogroup V mtDNAs. All mtDNAs with this mutation were then screened for a number of diagnostic RFLP sites, revealing two major subsets of mtDNAs. One is haplogroup V proper, and the other has been termed “pre*V,” since it predates V phylogenetically. The rather uncommon pre*V tends to be scattered throughout Europe (and northwestern Africa), whereas V attains two peaks of frequency: one situated in southwestern Europe and one in the Saami of northern Scandinavia. Geographical distributions and ages support the scenario that pre*V originated in Europe before the Last Glacial Maximum (LGM), whereas the more recently derived haplogroup V arose in a southwestern European refugium soon after the LGM. The arrival of V in eastern/central Europe, however, occurred much later, possibly with (post-)Neolithic contacts. The distribution of haplogroup V mtDNAs in modern European populations would thus, at least in part, reflect the pattern of postglacial human recolonization from that refugium, affecting even the Saami. Overall, the present study shows that the dissection of mtDNA variation into small and well-defined evolutionary units is an essential step in the identification of spatial frequency patterns. Mass screening of a few markers identified using complete mtDNA sequences promises to be an efficient strategy for inferring features of human prehistory.
PDF file
