Elucidation of the relationships of spiny-footed lizards, Acanthodactylus spp. (Reptilia : Lacertidae) using mitochondrial DNA sequence, with comments on their biogeography and evolution

Mitochondrial DNA sequences consisting of 645 sites from the 12S rRNA and 1 6S rRNA genes were used to estimate the phylogeny of 15 of the 32 species o f spiny-footed lizards Acanthodactylus. The resultant tree has similarities to that produced from a differentially weighted data set of 32 morphologic al characters but there are also significant differences. However, combined analysis of molecular and morphological data sets produces the same tree t opology as DNA sequence alone. The molecular data confirm that there are di stinct eastern and western clades within Acanthodactylus, but place A. bosk ianus in the former while the A. scutellatus group constitutes a third clad e. Species for which only morphological information is available were integ rated with the combined tree to give a provisional phylogeny for 31 species . This phylogeny indicates that the ancestor of existing Acanthodactylus pr obably originated in south-west Asia and that North Africa was invaded by m ore than one lineage of the genus. It also suggests that soft aeolian sand habitats may have been independently occupied more than once. Molecular dat a provide independent evidence that the differential weighting of morpholog ical characters in past analyses was appropriate.