Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard

Lizards that did not survive this cold event may have had genetic variants that would have made them more resilient to a heat wave or a drought—now those lineages may be lost.

Shane Campbell-Staton, Ph.D. ’15 and study lead-author

• States that extreme environmental perturbations offer opportunities to observe the effects of natural selection in wild populations
• States that during the winter of 2013–2014, the southeastern United States endured an extreme cold event
• The study authors use thermal performance, transcriptomics, and genome scans to measure responses of lizard populations to storm-induced selection
• Finds significant increases in cold tolerance at the species’ southern limit
• Finds that gene expression in southern survivors shifted toward patterns characteristic of northern populations
• Compares samples before and after the extreme winter, and finds 14 genomic regions were differentiated in the surviving southern population; four also exhibited signatures of local adaptation across the latitudinal gradient and implicate genes involved in nervous system function
• Results suggest that extreme winter events can rapidly produce strong selection on natural populations at multiple biological levels that recapitulate geographic patterns of local adaptation