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

Abstract

Phylogeography of the mitochondrial lineages commonly found in Western Europe can be interpreted in the light of a postglacial resettlement of the continent. The center of this proposal lies in the Franco-Cantabrian glacial refuge, located in the northern Iberian Peninsula and Southwestern France. Recently, this interpretation has been confronted by the unexpected patterns of diversity found in some European haplogroups. To shed new lights on this issue, research on Iberian populations is crucial if events behind the actual genetics of the European continent are to be untangled. In this regard, the region of Asturias has not been extensively studied, despite its convoluted history with prolonged periods of isolation. As mitochondrial DNA is a kind of data that has been commonly used in human population genetics, we conducted a thorough regional study in which we collected buccal swabs from 429 individuals with confirmed Asturian ancestry. The joint analysis of these sequences with a large continent-wide database and previously published diversity patterns allowed us to discuss a new explanation for the population dynamics inside the Franco-Cantabrian area, based on range expansion theory. This approximation to previously contradictory findings has made them compatible with most proposals about the postglacial resettlement of Western Europe.

Over the sands and far away: Interpreting an Iberian mitochondrial lineage with ancient Western African origins

“…After complete mtDNA characterization, the Asturian L3f1b6 lineages seem to be part of a putatively Iberian (perhaps even Southern European) haplogroup. Taking into account the maternal ancestry of the JQ703621.1 sequence, we can explain the relatively high ≈1% frequency in Asturias as a by‐product of the historical isolation of the Iberian north, as has been noted for other haplogroups affected by the resulting genetic drift (Garcia et al, ; Pardiñas et al, ). Nevertheless, although a recent migration cannot be completely discarded, regional African frequencies suggest an ancient origin for this lineage, even considering the isolation effect.…”

“…A remarkable case is the north‐western coastal region of Asturias, considered by historical sources to have suffered a certain demographic isolation until the 19th–20th centuries (Infiesta, ) and a low overall input of medieval Arab emigration (Ruiz de la Peña, ). Recently, both facts were suggested in an analysis of the mitochondrial hypervariable segment 1 (HVS1) of an ancestry‐controlled sample of 429 volunteers (Pardiñas et al, ). Among the seven individuals from L* lineages that were found, five could be ascribed to the uncommon haplogroup L3f1b4a, which was later supported by full control‐region sequencing (Pardiñas et al, ).…”

Evidence for Marine Consumption During the Upper Palaeolithic at “El Pirulejo” Inland Rock- Shelter (Southern Iberia Peninsula, Spain)

“…The Iberian Peninsula served as a faunal and human refugium during the Last Glacial Maximum when vast areas of the European continent were covered by ice (Bhagwat & Willis 2008;Finlayson & Carrión 2007;Holt 2003;Stewart & Stringer 2012). The transition between the extreme cold Heinrich stadial 1 (H1) (17.9 to 15.7 cal kyr BP) to the abrupt warming during the Bølling-Allerød interstadial (B-A) (~15.7 cal kyr BP) (Camuera et al 2021), with an estimated increase in sea surface temperatures of ~10ºC (Morcillo-Montalbá et al 2021), witnessed the last significant genetic population bottleneck in Eurasian prehistory until the Neolithic (Morin 2008;Pardiñas et al 2012;Fu et al 2016). Despite the impact of this transition on human populations, little is known about these communities' diets due to the low number of archaeological sites.…”