Morphological evolution in the day gecko Phelsuma sundbergi in the Seychelles: a multivariate study

Geographic variation was investigated in populations of the day gecko Phelsuma sundbergi from 22 islands in the Seychelles, using multivariate ordination procedures. Multiple group principal components analysis was used to negate ontogenetic variation. Seventy-eight characters from three character systems (body proportions, scalation and colour pattern) were analysed from 349 specimens. Three phenetic aggregations of granitic island populations were detected from the northwestern, northeastern and southern island groups. A comparison of the results from the three character systems analysed separately suggests that the separation of the southern form preceded that of the northern forms. Colour pattern characters reflect this closely, while body proportions and scalation characters follow evolution of body size. The populations of Phelsuma sundbergi on the coralline islands are not well differentiated from the races on the granitic islands, and probably represent recent colonizations or introductions by man.