Clines and Cause: Microgeographic Variation in the Tenerife Gecko (Tarentola Delalandii)

Geographic variation in color pattern, body dimensions, and scalation of the lowaltitude populations of the Tenerife gecko (Tarentola delalandii) is analyzed and depicted by multivariate ordination and contouring. Comparison with parallel geographic variation in other lizards on Tenerife and an adjacent island suggests an “ecogenetic” rather than “phylogenetic” cause (i.e., adaptation to current latitudinal habitat types with different climate and vegetation). Three quantitative procedures that may be of use in distinguishing between ecogenetically and phylogenetically caused geographic variation are used to test the geographic variation in the Tenerife gecko (i.e., investigating congruence by random resampling, anagenesis in putative phylogenetic trees, and partial correlation/Mantel tests). The latter two procedures appear to be the most useful; in particular, simultaneous Mantel tests indicate that scalation is significantly associated with latitudinal habitat types irrespective of the effects of spatial proximity. [Geographic variation; multivariate analysis; contours; hypothesis testing; population phylogenesis; ecogenetics; resampling; simultaneous Mantel tests; Tarentola delalandii.]