Distribution of genetic variation and taxonomy of insular and mainland populations of the Italian wall lizard, Podarcis sicula

Abstract

AbstractThe genetic structure and heterogeneity of Podarcis sicula (Reptilia, Lacertidae) was studied in insular (Pontine Archipelago) and mainland (central and southern Italy) populations by means of allozyme electrophoresis at 20 presumptive gene loci. Genetic variability in the species is low and genetic subdivision is high. The highest values of percent polymorphism and heterozygosity were found in the samples from the southernmost part of Italy (Calabria). The insular samples from the Pontine Archipelago were characterized by loss of alleles and erosion of genetic variability. Population heterogeneity analysis carried out by the estimation of Wright's F-statistics demonstrated substantial genetic differentiation among populations. F-statistics and genetic distance data show that genetic variation is distributed into three population groups. The first group includes the genetically very similar populations from central Italy and the Pontine Archipelago, the second includes the populations from Campania (southern Italy), the third comprises the populations from the southernmost part of the Italian Peninsula (Calabria). Based on the results of the allozyme data, the systematic status of the subspecies of P. sicula occurring in the studied areas is discussed.