Widespread correlations between climatic niche evolution and species diversification in birds

Area of Science:

• Evolutionary Biology
• Ecology
• Biogeography

Background:

• Species' climatic niche adaptability influences colonization, gene flow, speciation, and extinction.
• Previous studies on climatic niche evolution and diversification used limited samples, yielding inconclusive results.
• The link between climatic niche evolution and diversification remains poorly understood.

Purpose of the Study:

• To investigate the correlation between climatic niche evolution rates and species diversification in birds.
• To determine if biogeographical and ecological factors modify the relationship between niche evolution and diversification.
• To understand the role of climatic niche evolution in regulating the climate-biodiversity link.

Main Methods:

• Quantified climatic niches, latitudinal distribution, and ecological traits for 7657 bird species.
• Utilized Bayesian phylogenetic analyses to examine relationships between niche evolution, species richness, and diversification rates.
• Assessed patterns across genus- and family-level avian clades.

Main Results:

• A positive linear relationship exists between the rate of climatic niche evolution and both species richness and diversification rate.
• This association was consistent across genus- and family-level clades.
• The link between labile climatic niches and diversification was independent of clade latitude and ecological traits.

Conclusions:

• Rapid climatic niche evolution is a significant driver of avian diversification.
• Either niche lability promotes diversification, or diversification fosters niche lability.
• Climatic niche evolution is a fundamental process linking climate and global biodiversity, irrespective of geographical or ecological context.