Local adaptation has a role in reducing vulnerability to climate change in a widespread Amazonian forest lizard.

Abstract

The extant genetic variation within and among taxa reflects a long history of diversification and adaptive mechanisms in response to climate change and landscape alterations. However, the velocity of current anthropogenic changes poses an imminent threat to global biodiversity. Understanding how species and populations might respond to global climate change provides valuable information for conservation in the face of these impacts. Here, we use genomic data to observe candidate loci under climate selection and test for genetic vulnerability to climate change in a widespread Amazonian ombrophilous lizard population. We found nine populations across Amazonia with a considerable amount of admixture among them. Distinct approaches of genome-environment association analyses revealed 56 candidate single-nucleotide polymorphisms (SNPs) under climatic selection, showing an east-west gradient in the adaptive landscape and a signal of local climate adaptation across the species range. According to our results, signals of local adaptation indicate that the species may not respond equally throughout its range, with some populations facing higher extinction risks. Genomic offset analysis predicts the southern and central portions of Amazonia to have a higher vulnerability to future climate change. Our findings highlight the importance of considering spatially explicit contexts with a large sampling coverage to evaluate how local adaptation and climatic vulnerability affect Amazonian forest ectothermic fauna.