SICB 2015: Genetics and Geography: Patterns of Brown Anole Diversification

Anolis sagrei, the almost-ubiquitous brown anole, has spread across a broad geographical range that spans most of the Caribbean. The populations across this range, however, vary extensively in morphological traits. Graham Reynolds, currently a postdoc working with Liam Revell and Jonathan Losos, summarized this morphological variation and described a large-scale phylogeographic study of population differentiation in brown anoles in a talk at SICB on Tuesday.

The context of Graham’s study arose from Lister’s classic 1976 paper showing variation in the number of toe pad lamellae in brown anole populations from different Caribbean islands. Lister found that average lamellae number corresponded to average perch height. More recently, Veronica Gomez-Pourroy’s masters thesis work showed that brown anole morphology varies across mainland Central America, the Swan Islands of Honduras, and the Caribbean.

Graham’s genetic work expanded on the results of Kolbe et al. (2004) and included samples collected by a large number of collaborators working in 95 localities throughout the Caribbean Basin. Using multilocus nuclear and mitochondrial data, Graham found a large split between the Eastern and Western Cuban clades of brown anoles. Populations from the Bahamas clustered with the Western Cuban clade, and populations from the Swan Islands and Central America were most related to populations from the southern populations of the Eastern Cuban clade.

Graham’s overall aim is to integrate morphology, behavior, and genetics from local to regional scales. Anoles seem to be the perfect group with which to tackle this goal!