Ricerc@Sapienza

During the first decades of the last Century an enigmatic extinction was documented to have occurred on the small Mediterranean island of Santo Stefano and Sherlock Holmes was jokingly evoked to solve the mystery. Although islands are fascinating systems where to study microevolutionary processes, they may, on the other hand, host unstable communities that make their populations particularly vulnerable to anthropogenic effects and even to extinctions.

In recent years, great attention has been paid to many Podarcis species for which the observed intra-specific variability often revealed species complexes still characterized by an unresolved relationship. When compared to other species, P. siculus underwent fewer revisions and the number of species hidden within this taxon may have been, therefore, underestimated. However, recent studies based on genetic and morphological data highlighted a marked differentiation of the populations inhabiting the Western Pontine Archipelago.

Background: The current distribution of genetic diversity is the result of a vast array of microevolutionary processes, including short-term demographic and ecological mechanisms and long-term allopatric isolation in response to Quaternary climatic fluctuations. We investigated past processes that drove the population differentiation and spatial genetic distribution of the Italian wall lizard Podarcis siculus by means of sequences of mitochondrial cytb (n = 277 from 115 localities) and nuclear mc1r and ?-fibint7genes (n = 262 and n = 91, respectively) from all its distribution range.