Phylogeography and natural selection in the Tenerife gecko Tarentola delalandii: testing historical and adaptive hypotheses

Combining phylogeographic and matrix correspondence approaches in the analy sis of geographical variation provides a fruitful approach to inferring the causes of molecular and morphological evolution within species. Here we pr esent a study on the gecko Tarentola delalandii on the island of Tenerife, Canary Islands, which provides an outstanding model of an exceptionally hig h degree of phylogeographic differentiation in magnitude and pattern on a s mall spatial scale. We reconstruct the population history of T, delalandii using phylogeographic information matrix correspondence tests and estimates of divergence times in conjunction with geological data. It appears that p opulations differentiated on three precursor islands and secondary contact followed the junction of these islands. The cytochrome b sequence appears t o be evolving at least at approximate to 1% per million years in this speci es. Matrix correspondence tests indicate that morphological character syste ms may reflect ecological selection regimes (colour pattern), history (body dimensions) or both (scalation). The results imply that natural selection can override a historical legacy but also underline the potential relevance of molecular phylogenetic data for the interpretation of geographical vari ation in morphology.