Local Adaptation in Climate Tolerance at a Small Geographic Scale Contrasts With Broad Latitudinal Patterns.

Area of Science:

• Evolutionary biology
• Ecology
• Climate change research

Background:

• Climate adaptation is often studied across broad geographic gradients.
• The potential for adaptation at local scales within heterogeneous environments is less understood.
• Understanding local adaptation is crucial for predicting species' responses to global change.

Purpose of the Study:

• To investigate if local-scale environmental heterogeneity can drive adaptation patterns similar to broad latitudinal gradients.
• To quantify population variation in climate tolerance traits and plasticity in Drosophila melanogaster.
• To compare local adaptation patterns with those observed across a wide latitudinal range.

Main Methods:

• Studied five Drosophila melanogaster populations along a 3000-km latitudinal gradient.
• Contrasted latitudinal data with eight local populations from a 600 × 300 km heterogeneous area.
• Quantified population variation in stress tolerance (heat, desiccation) and trait plasticity.

Main Results:

• Local-scale population variation in stress tolerance was comparable to variation across the latitudinal gradient.
• Populations from warmer, drier areas exhibited higher heat and desiccation tolerance.
• Populations from more predictable environments demonstrated greater plasticity.

Conclusions:

• Climate adaptation at local geographic scales can be as significant as adaptation across broad scales.
• Local adaptation patterns can vary across different geographic contexts, complicating predictions of global change responses.
• Adaptive capacity to global change may be underestimated if local environmental heterogeneity is not considered.