A survival story: evolutionary history of the Iberian Algyroides (Squamata: Lacertidae), an endemic lizard relict

The Iberian Algyroides (Algyroides marchi) is a lacertid lizard with one of the narrowest distribution ranges in continental Europe, restricted to a minute area in the Subbaetic mountains in SE Spain. Due to specific habitat requirements, this species is considered threatened by climate change and habitat degradation. Here, an improved and time-calibrated multilocus phylogenetic analysis, combining two mitochondrial, three nuclear markers as well as a battery of 12 microsatellite loci, was performed. Moreover, ancestral changes in effective population size were determined under Approximate Bayesian Computation (ABC) analysis. In parallel, past, present and future habitat suitability was inferred using Ecological Niche Models (ENMs). The diversification of A. marchi in the Iberian Peninsula began during the Upper-Pleistocene around 0.10 Mya. However, during the Last Interglacial the species had much larger suitable habitats along NE Iberia and/or the Cantabrian region. Indeed, ABC analysis indicates that not the Last Interglacial, but instead the Last Glacial Maximum led to a population bottleneck followed by a recovery/expansion. The footprint of this complex evolutionary history is reflected today in six monophyletic lineages, with little genetic differentiation and geographic coherency. This pattern most likely arises from the climatic oscillations during the Pleistocene, leading to a complete range shift and secondary contact, with very divergent haplogroups in sympatry and exchanging genes. Finally, the ENMs predict a considerable future retraction and shift in the area suitable for the species, which should be taken into account for conservation policies.