Genetic and morphometric differentiation among island populations of two Norops lizards (Reptilia: Sauria : Polychroticlae) on independently colonized islands of the Islas de Bahia (Honduras)
2007 (English)In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 34, no 7, 1124-1135 p.Article in journal (Refereed) Published
Aim: Anole lizards (Reptilia: Sauria: Polychrotidae) display remarkable morphological and genetic differentiation between island populations. Morphological differences between islands are probably due to both adaptive (e.g. differential resource exploitation and intra- or interspecific competition) and non-adaptive differentiation in allopatry. Anoles are well known for their extreme diversity and rapid adaptive speciation on islands. The main aim of this study was to use tests of morphological and genetic differentiation to investigate the population structure and colonization history of islands of the Islas de Bahia, off the coast of Honduras. Location Five populations of Norops bicaorum and Norops lemurinus were sampled, four from islands of the Islas de Bahia and one from the mainland of Honduras. Methods Body size and weight differentiation were measured in order to test for significant differences between sexes and populations. In addition, individuals were genotyped using the amplified fragment length polymorphism technique. Bayesian model-based and assignment/exclusion methods were used to study genetic differentiation between island and mainland populations and to test colonization hypotheses. Results Assignment tests suggested migration from the mainland to the Cayos Cochinos, and from there independently to both Utila and Roatan, whereas migration between Utila and Roatan was lacking. Migration from the mainland to Utila was inferred, but was much less frequent. Morphologically, individuals from Utila appeared to be significantly different in comparison with all other localities. Significant differentiation between males of Roatan and the mainland was found in body size, whereas no significant difference was detected between the mainland and the Cayos Cochinos. Main conclusions Significant genetic and morphological differentiation was found among populations. A stepping-stone model for colonization, in combination with an independent migration to Utila and Roatan, was suggested by assignment tests and was compatible with the observed morphological differentiation.
Place, publisher, year, edition, pages
2007. Vol. 34, no 7, 1124-1135 p.
AFLP, assignment-based methods, biogeography, Honduras, island populations, migration, Norops, population genetics
IdentifiersURN: urn:nbn:se:kth:diva-37053DOI: 10.1111/j.1365-2699.2007.01691.xISI: 000248179800002ScopusID: 2-s2.0-34250754479OAI: oai:DiVA.org:kth-37053DiVA: diva2:431918