Mitochondrial D-loop phylogeny signals two native Iberian red deer (Cervus elaphus) Lineages genetically different to Western and Eastern European red deer and infers human-mediated translocations

Native red deer (Cervus elaphus) in Western Europe might at least partially derive from refugial populations which survived in the Iberian Peninsula during the last glacial maximum, and that expanded northwards at the onset of the Holocene. However, the phylogeny and genetic structure of red deer populations in the Iberian Peninsula are still poorly known. This study was planned, in a first step, to reconstruct the phylogenetic relationship of the main red deer populations extant in Spain by the analyses of an extensive sample of mitochondrial DNA sequences. Results indicate that sequences from these populations can be assigned to one of two deeply divergent mtDNA lineages (South-Western and Central-Eastern) with molecular divergence nearby the 2 %. In each lineage were respectively found sixteen and thirteen different haplotypes. It was evidenced that they may be allopatrically distributed in Spain with 86.6 % sequences of the South-Western lineage at the South-Western side and the 65 % sequences of Central-Eastern lineage in the Central-Eastern side. These mitochondrial lineages might have originated in two distinct refugial populations during the last glacial maximum. Genetic data also reveal instances of admixture between native populations and translocated European red deer, which belong to at least three distinct subspecies. Gene introgression was mainly due to red deer from Western European populations. The genetic contribution of red deer translocated from Eastern Europe (C. e. hippelaphus) or North Africa (C. e. corsicanus, C. e. barbarus) was apparently less deep. The extant phylogenetic relationship and evidences of genetic admixture suggest that sound conservation actions for the native Iberian red deer should severely restrict the introduction of alien red deer and, when possible, avoid admixture between the South-Western and Central-Eastern mtDNA lineages.