Latitudinal variation in climate-associated genes imperils range edge populations

Area of Science:

• Ecology
• Evolutionary Biology
• Climate Change Science

Background:

• Global temperature increases cause widespread ecological impacts.
• Understanding how climate variation drives natural selection and adaptive resilience across latitudes is crucial.
• Latitudinal gradients offer a framework for testing ecosystem-level theories of climatic adaptation.

Purpose of the Study:

• To assess adaptive diversity differences in rainbowfish (Melanotaenia duboulayi) populations across a latitudinal gradient.
• To investigate the influence of climatic variation, specifically stream flow and temperature, on genetic and phenotypic adaptation.
• To test the 'climatic variability hypothesis' regarding adaptive divergence at environmental range margins.

Main Methods:

• Environmental mapping and data integration.
• Analysis of phenotypic variation and genome-wide data from rainbowfish populations.
• Controlling for spatial population structure to identify genotype-environment interactions.

Main Results:

• Detected significant genotype-environment interactions linked to stream flow and temperature variations.
• Identified hydroclimate-associated genes interacting in networks with adaptive significance for future climates.
• Observed that populations at environmental extremes exhibited stronger adaptive divergence and reduced genetic variation in climate-associated genes compared to central populations.

Conclusions:

• Populations at environmental range margins and geographical edges may be more susceptible to climate change.
• Findings have implications for predicting adaptive resilience in species.
• Highlights the importance of considering hydroclimatic selection in biodiversity management under climate change.