Skull size and shape variation versus molecular phylogeny:a case study of alpine newts (Mesotriton alpestris, Salamandridae)from the Balkan Peninsula

摘要

We explored the phylogenetic signal of skull size and shape in alpine newts from the Balkans, a group of European newts that, in spite of their considerable phyloge-ographic substructuring (as inferred from previous DNA analyses), maintain a conservedphenotype. In terms of skull shape disparity, geometric morphometries show that the dorsal cranium carries a significant phylogenetic signal, the most notable evidence in this present study. On the contrary, no phylogenetic signal in the shape of the ventral cranium was found. This result indicates that the variation in the shape of the ventral cranium is more prone to other factors and processes, such as adaptations to local environments rather than phylogenetic constraints. Variation in skull size within alpine newts seems to be independent from phylogenetic constraints.