Melting pots and hotspots: genetic variation within Acanthodactylus erythrurus (Reptilia: Lacertidae) from the Iberian Peninsula

Abstract

Abstract Identification of high levels of intraspecific genetic variability is common among assessments of reptiles from the Iberian Peninsula, conforming to the “refugia within refugia” hypothesis. Divergent genetic lineages are often found to be allopatric, or with limited contact or hybrid zones; such zones are more widely reported in Northern Europe, leading to the “melting pots not hotspots” hypothesis. However, population level sampling is needed to determine if divergent lineages overlap, something that is often missing in phylogenetic studies. Mitochondrial genetic diversity was assessed within the lacertid lizard Acanthodactylus erythrurus across the Iberian Peninsula. Not only were highly divergent lineages recovered in the southern region, but also considerable admixture of these was identified, particularly in northern populations. This has implications for biogeographic scenarios, with patterns typically identified at a larger scale emerging within a single European southern refugium. It also indicates that divergent mtDNA lineages appear to freely mix, at least within this species, which has taxonomic implications.