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Genetica di popolazione di Archaeolacerta bedriagae (Reptilia, Lacertidae) e valutazioni tassonomiche
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Interpreting dispersal patterns of reproductive female Hierophis viridiflavus (LACEPEDE, 1789), around a communal nesting site (Squamata: Serpentes: Colubridae)
No full textHow many Archaeolacerta inhabit the Corso-Sardinian Plate? Allozyme variation and differentiation in Archaeolacerta bedriagae (Camerano, 1885)
No full textArchaeolacerta bedriagae is a rock lizard endemic to Corsica and Sardinia. Four subspecies have been recozied
to date on the basis of morphological traits. Previous allozyme investigations revealed high genetic differentiation among
populations of the species. Based on these results some authors hypothesized that more than one species of Archaeolacerta
may occur on Corsica and Sardinia. In this paper we investigated allozyme variation at 19 gene loci in 5 populations belonging
to all subspecies of A. bedriagae in order to study genetic differentiation among populations from Corsica and Sardinia,
and to compare our results with those obtained in previous studies carried out on allozyme variation and taxonomy of the
species. Low levels of genetic differentiation (average Nei’s D = 0.026) and heterogeneity (mean FST = 0.147) were found
comparing the A. bedriagae populations, and there was no evidence of interruption or restriction of gene flow. This is in
agreement with the available molecular and morphometric data, while it is not in accordance with allozyme data reported in
the previous studies. Our data do not support the hypothesis of an unrecognized criptic species of Archaeolacerta in Corsica
and Sardinia, and indicate that the definitive assessment of the taxonomic status of the A. bedriagae populations requires
further investigation
Offspring condition determines dispersal patterns in western whip snakes, Hierophis viridiflavus
No full text"Dispersal patterns from a communal nesting\/birth site of hatchlings of the oviparous colubrid snake Hierophis viridiflavus were investigated using capture-mark-recapture data from a 17-year study. We found that hatchlings lighter at birth dispersed more than heavier ones, whereas after one year there was no difference in body mass between the individuals which rested close to their birth site and those which dispersed further. We interpret this result as an adaptive dispersal behaviour in which heavier newborn snakes are less inclined to disperse from the hatching site, whereas lighter snakes move further away to increase their foraging efficiency.
The decline of the Aeolian wall lizard, Podarcis raffonei: causes and conservation proposals
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Pelophilax bergeri (Gunther, In Engelmann, Fritzche, Gunther & Obs, 1986) - Pelophlax klepton hispanicus (Bonaparte, 1839)
No full textGenetic variation and its evolutionary inmplications in a Mediterranean island endemic lizard
No full textThe peculiar bioclimatic and geographic features of Corso-Sardinian islands may provide an ideal scenario for investigating microevolutionary processes, given their large heterogeneity of environments, which could affect dispersal and gene flow among populations, as well as processes of local adaptation. The genetic variation and differentiation among populations of the endemic lizard Archaeolacerta bedriagae were studied by allozyme electrophoresis at 20 presumptive loci. The genetic structure of this species is characterized by relatively high levels of polymorphism and low differentiation among populations. The pattern of genetic differentiation cannot be explained by genetic drift as a function of geographic distance. Genetic distance data show that genetic variation is distributed into three geographically coherent population groups and suggest a recent (Late Pleistocene) origin for the observed geographic fragmentation. The analysis of environmental correlates of allozymic variation indicates a strong correlation of the Idh-1 locus with climatic variables. The frequency of the Idh-1106 allele is negatively correlated with annual temperature, and positively correlated with annual precipitation. In addition, the observed heterozygosity at this locus decreases towards more arid climatic regimes. The results obtained support the assumption of differential selection acting on Idh-1 allozymes under diverse climates. An association between Idh-1 allozymes and local bioclimatic regimes was also observed for the sympatric lizard Podarcis tiliguerta, suggesting a key role for such selective agents on Idh-1 polymorphism in these two Corso-Sardinian lacertid
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