Microsatellite data show evidence for male-biased dispersal in the Caribbean lizard Anolis roquet


R. S. Thorpe, Fax: +44 (0) 1248 370731; E-mail: r.s.thorpe@bangor.ac.uk


Dispersal is a key component of an organism's life history and differences in dispersal between sexes appear to be widespread in vertebrates. However, most predictions of sex-biased dispersal have been based on observations of social structure in birds and mammals and more data are needed on other taxa to test whether these predictions apply in other organisms. Caribbean anole lizards are important model organisms in various biological disciplines, including evolutionary biology. However, very little is known about their dispersal strategies despite the importance of dispersal for population structure and dynamics. Here we use nine microsatellite markers to assess signatures of sex-biased dispersal on two spatial sampling scales in Anolis roquet, an anole endemic to the island of Martinique. Significantly higher gene diversity (HS) and lower mean assignment value (mAIC) was found in males on the larger spatial sampling scale. Significant heterozygote deficit (FIS), lower population differentiation (FST), mAIC and variance of assignment index (vAIC) was found in males on the smaller spatial scale. The observation of male biased dispersal conform with expectations based on the polygynous mating system of Anolis roquet, and contributes to an explanation of the contrasting patterns of genetic structure between maternal and biparental markers that have been reported previously in this, and other anoline, species.