A new study analyzing the genomes of yellow warblers in North America reveals how some subpopulations are more "genetically vulnerable" to changes associated with climate change; furthermore, it finds that genes linked to exploratory and migratory behavior may be important for successful climate adaptation. Climate change is having a dramatic impact on Earth's biodiversity, where rapid fluctuations in temperature and precipitation are altering environments. To better understand the potential ability of species to adapt to these changes, Rachael Bay et al. analyzed genetic data from 229 yellow warblers (Setophaga petechia) - which live in a range of habitats, from marshes and forests to urbanized areas - living in different sites across North America. The data reveal that populations vary genetically across the landscape. The researchers then looked at the relationship between each subpopulation's genomic variation and its respective environment, comparing these data to predictions of how future genetic variation may allow for adaptation to changes in future environments. Precipitation was found to be the climate factor with the strongest association with specific genomic traits, a phenomenon that might explain why the subpopulations determined to have the "highest genomic vulnerability" (or greatest mismatch between current genomic traits and those needed to adapt to environmental change) occur from the southern Rocky Mountains to Alaska, a region suffering from droughts over recent years. Unsurprisingly, genomic vulnerability increases under more severe climate change scenarios. Two genes associated with migration, DRD4 and DEAF1, were found to be protective against the effects of climate change. The authors note that DRD4 in particular, a dopamine receptor, has been extensively studied for its involvement in novelty-seeking behavior in primates, fish, and birds. Mark Fitzpatrick and Allan Edelsparre discuss these findings in a related Perspective.
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Journal
Science