Using mitochondrial DNA to test the hypothesis of a European post-glacial human recolonization from the Franco-Cantabrian refuge

Abstract

It has been proposed that the distribution patterns and coalescence ages found in Europeans for mitochondrial DNA (mtDNA) haplogroups V, H1 and H3 are the result of a post-glacial expansion from a Franco-Cantabrian refuge that recolonized central and northern areas. In contrast, in this refined mtDNA study of the Cantabrian Cornice that contributes 413 partial and 9 complete new mtDNA sequences, including a large Basque sample and a sample of Asturians, no experimental evidence was found to support the human refuge-expansion theory. In fact, all measures of gene diversity point to the Cantabrian Cornice in general and the Basques in particular, as less polymorphic for V, H1 and H3 than other southern regions in Iberia or in Central Europe. Genetic distances show the Cantabrian Cornice is a very heterogeneous region with significant local differences. The analysis of several minor subhaplogroups, based on complete sequences, also suggests different focal expansions over a local and peninsular range that did not affect continental Europe. Furthermore, all detected clinal trends show stronger longitudinal than latitudinal profiles. In Northern Iberia, it seems that the highest diversity values for some haplogroups with Mesolithic coalescence ages are centred on the Mediterranean side, including Catalonia and South-eastern France.

Echoes from Sepharad: signatures on the maternal gene pool of crypto-Jewish descendants

“…48 However, the low gene and nucleotide diversities found in this region and in Northern Africa, compared with the ones found in North-Central Europe, seem to exclude Eastern Europe as a possible focus of expansion. 49,50 In the Iberian Peninsula, HV0 is a rare haplogroup, found at low frequencies in NW Spain, Zamora (4.7%), 51 a Spanish province geographically close to Braganc¸a. Because of a lack of resolution, it is not possible to differentiate haplogroup V inside HV0 in the Portuguese population.…”

Sephardic signature in haplogroup T mitochondrial DNA

“…Studies for comparison populations were selected on the basis of large size and availability. If frequencies of subhaplogroups were provided in the text 13,24,25 or in online supplementary material, 26,27 those assignments were used with the assumption that T3¼T2c, T5¼T2e, and T*¼T other. Otherwise, control region 1 sequences were inspected in the text 24,28 or supplementary materials 4,5,26,29,30 and assigned to subhaplogroups of T. Assignment criteria used were 16163G-16189C (T1), 16304C (T2b), 16292T (T2c), 16153A (T2e), 16324C (T4) within the context of also having 16126C, 16294T (T); remaining motifs were assigned as 'T other' .…”

Mitochondrial diversity patterns and the Magdalenian resettlement of Europe: new insights from the edge of the Franco-Cantabrian refuge

“…This range is sufficient for our analyses, as it includes the most polymorphic interval of the entire hypervariable region. 49 Data for the diversity of the haplogroups H1, H3, K, T2b, W, HV0 and V were computed from the Asturian haplotypes and obtained from the Garcia et al study 9 for nine European regions and Northern Africa, including the Franco-Cantabrian area. Values for the y K and K P parameters were also computed for these regions using the most approximate populations of our HVS-I data set (Supplementary Table S3), with the aim of performing model fitting on the diversity data.…”

“…7,8 Lately, this idea has been criticized with the argument that while the frequencies of European postglacial haplogroups are the highest in Franco-Cantabrian populations, they also show their lowest molecular diversities there. 9 Furthermore, marked heterogeneities in haplogroup composition appear even between geographically close populations of this area, which are probably related to genetic drift due the steep relief of northern Iberia. Both evidences point to the possibility that the Franco-Cantabrian genetic makeup may have evolved discretely and differently from the rest of Europe, and may not be adequate for inferring continental patterns.…”

“…32,33 To our knowledge, the only other sizeable population genetic study is the one from Garcia et al, 9 which used 89 samples collected in Asturias. They noted the aforementioned pattern of local drift as a possible cause for the differences between Asturias and other regions of the Franco-Cantabrian area, but a greater number of samples is likely needed to achieve an unbiased representation of Asturian mtDNA lineages.…”