Genetic variation across a species’ range means that subtle differences, even those spread across hundreds or thousands of miles, may have big implications for how well discrete populations weather change.

A new study in Nature Communications details how genetic variation across the native range of brook trout may help some trout populations endure rising temperatures better than others. These findings demonstrate how local adaptations could hold important keys for species survival, including how they could be used to help bolster the resilience of at-risk populations through well-informed conservation strategies.

Conservation biologist Mariah Meek, a professor at Michigan State University and lead author on the study, explains that such layered insights help scientists understand how different populations of the same species could respond to climate change in unique ways. Populations of organisms can develop specific adaptations to the conditions they’re exposed to over time. In brook trout, adaptations to conditions like rainfall, humidity and temperature can be written into their DNA. But the brook trout’s native range spans thousands of miles — and across that range, different groups occupy varied bodies of water, from deep lakes to streams — and experience stark differences in conditions like temperature and rainfall.