Comparing morphological variability and molecular divergence: a preliminary study in Podarcis muralis (laurenti, 1768) from the Tuscan Archipelago (Italy)

The genus Podarcis (Wagler, 1830) has evolved and diversified in the Mediterranean Basin, where it represents the predominant reptile group. In recent years, analysis of DNA sequences has significantly revised the traditional systematic of Podarcis species based on morphological characters. In particular, sometimes subspecies may deserve species status, while in other cases their phenotypic divergences are thought to be due to local adaptation, so that they should be better regarded as eco-phenotypes. The Common wall lizard, Podarcis muralis (Laurenti, 1768), is widespread in southern, western and central Europe, where it has spread in a wide variety of habitats. The high morphological variability of this species have given rise in the past to a complex taxonomic framework, allowing the proliferation of many morphological subspecies. In particular, seven subspecies exclusive of the Tuscan Archipelago were recognized, mainly due to the chromatic polymorphism of the insular populations. Here, we used molecular markers, that are less influenced by local adaptation than morphological characters, to investigate the genetic variability of P. muralis populations. DNA sequences were obtained from museum specimens representing all morphological subspecies indicated for the Tuscan Archipelago. Our results do not completely agree with the morphological subspecific division in P. muralis: in fact, several morphological subspecies show minimal or no difference in mtDNA haplotypes. Nevertheless, a strong genetic structure was found in our dataset, that may be useful in clarifying the biogeography of the Archipelago, providing new highlights about the genetic variation and the phylogeny of this species too.