Phylogenetic Analysis of the Complete Mitochondrial Genomes in the Ten Rupicapra Subspecies and Implications for the Existence of Multiple Glacial Refugia in Europe

SIMPLE SUMMARY: The successive glaciations that took place during the Pleistocene shaped de distribution of temperate species in Europe, both plants and animals. Traditionally, it has been hypothesized that during the coldest periods, species took refuge in three areas of southern Europe (Iberian, Italian and Balkan peninsulas) and then recolonized the north when temperatures rose and conditions were more favorable. In the present work, the complete mitochondrial sequences of the ten described chamois populations have been analyzed to identify which areas of the continent have served as refuges for the species during the glaciations. The results of the present work are consistent with the existence of multiple glacial refugia across Europe, revealing a much more complex picture of the effect of glaciations on the genetics of temperate species than is commonly accepted, giving us a better understanding of how past events determine the present species. ABSTRACT: The current distribution of populations in Europe is marked by the effects of glaciations that occurred during the Pleistocene. Temperate species were isolated in glacial refugia that were the sources of postglacial recolonization. The traditional glacial refuge areas were the Iberian, the Italian and the Balkan peninsulas. Here we revisit the evolutionary history of chamois (Rupicapra genus) to evaluate other sites in continental Europe and Anatolia that have been suggested as potential refuges. We have obtained the complete mitochondrial sequence of seven chamois, including the subspecies parva, carpatica, caucasica, and asiatica whose mitochondrial genome had not been yet reported. These, together with the other fourteen sequences already in the GenBank, represent the different geographical populations of the Rupicapra genus. The phylogenetic analysis showed the three old clades, dating from the early Pleistocene, already reported: mtW in the Iberian Peninsula, mtC in the Appenines and the Massif of Chartreuse, and mtE comprising all the population from the Alps to the east. The genomes within each of the clades mtW and mtE, showed divergence times larger than 300 thousand years. From here, it can be argued that the present-day lineages across Europe are very old and their split dates back to the middle Pleistocene.