Higher temperatures lower rates of physiological and niche evolution

Area of Science:

• Evolutionary biology
• Physiological ecology
• Climate change biology

Background:

• Rising global temperatures pose significant threats to species.
• Understanding species' physiological and climatic niche evolution is critical.

Purpose of the Study:

• To test fundamental hypotheses about physiological and niche evolution in vertebrates.
• To investigate rates of change in physiological tolerances and climatic niches.

Main Methods:

• Phylogenetic methods applied to published data from 2059 vertebrate species.
• Analysis of evolutionary rates for physiological tolerances (heat/cold) and climatic niche variables.

Main Results:

• Physiological tolerances to heat evolve slower than to cold.
• Hottest climatic niche temperatures change slower than coldest temperatures.
• Physiological tolerances evolve slower than corresponding climatic niche variables, with observed mismatches.

Conclusions:

• Species' physiological tolerances and climatic niches evolve at different rates.
• Mismatches between climate and physiology may reflect activity patterns and microhabitats, not just large-scale distributions.