Summary from the authors: Selection at behavioural, developmental and metabolic genes is associated with the northward expansion of a successful tropical colonizer

Link to paper: https://onlinelibrary.wiley.com/doi/10.1111/mec.15162

Picture: Green Anole Lizard (Anolis carolinensis) on railing in Hilo, Hawaii. Author: Paul Hirst. CC-BY-SA-2.5

The green anole (Anolis carolinensis), also called the American chameleon due to its ability to change color, is a common species in South-East USA. It has been studied for decades to understand how reptiles adapt to their environment.  Unlike other species of its genus, its range encompasses territories outside tropical climate, reaching the winter-exposed flanks of the Appalachians. The green anole colonized these colder regions from Florida in the last 300,000 years. We used DNA variation covering the whole genome and contrasted populations having recently colonized colder territories with the ones from tropical Florida. We compared multiple approaches to detect which segments in DNA sequences harbored variation compatible with selection. Since these signatures can also be produced by past demography, we took the latter into account to limit the detection of false positives. We then identified the most likely function of genes overlapping with candidate regions for selection, and observed that many of those were involved in exploratory behavior, immunity and response to cold. This suggests that the success of green anoles may have been due to changes in both physiology and behavioral shifts, a hypothesis that could be further tested experimentally.

Yann Bourgeois and Stephane Boissinot

Bourgeois, Y., & Boissinot, S. (2019). Selection at behavioral, developmental and metabolic genes is associated with the northward expansion of a successful tropical colonizer. Molecular Ecology. 2019. 28-15. 3523-3543