Skip to main content
Dryad

Environmentally-associated color divergence does not coincide with population structure across Lesser Antillean anoles

Jung, Catherine1; Yuan, Michael1

Published May 02, 2025 on Dryad. https://doi.org/10.5061/dryad.xksn02vq0

Data files

May 02, 2025 version files 12.19 KB

Click names to download individual files

Abstract

Species distributed across heterogeneous environments may undergo local adaptation, which can be limited by the homogenizing effects of gene flow. Lesser Antillean anoles exhibit dorsal color variation associated with dramatic shifts in environment across small spatial scales, providing an excellent system for studying the maintenance of local adaptation despite ongoing gene flow. The 1995 Soufriere Hills eruption on Montserrat provides an opportunity to understand how natural disasters may influence evolution of insular species. Thus, our study had two main objectives. First, we collected genetic, phenotypic, and environmental data to investigate whether environmentally-associated dorsal coloration reflects underlying population structure in three species of Lesser Antillean anoles. Second, we examined the short-term evolutionary consequences of volcanism by comparing pre- and post-eruption samples of Anolis lividus using multi-locus sequence data. We found all three species exhibited genetic isolation- by-distance but not isolation-by-environment. Furthermore, phenotypic differences within each species were not predicted by genetic distances, suggesting gene flow across color morphs. We confirmed the repopulation of A. lividus in the impacted area and found genetic diversity equivalent to pre-eruption sampling. Our findings contribute to our understanding of local adaptation in spatially small-scale systems and the impact of catastrophic natural disasters on population structure.