Sexual selection, body mass and molecular evolution interact to predict diversification in birds

Area of Science:

• Evolutionary biology
• Genomics
• Ornithology

Background:

• Sexual selection significantly impacts microevolutionary and macroevolutionary processes.
• The precise mechanisms linking sexual selection to macroevolutionary diversification remain largely unexplored.
• Birds, with their diverse reproductive strategies and evolutionary radiations, offer a prime model system for studying these links.

Purpose of the Study:

• To investigate the mechanisms by which sexual selection influences macroevolutionary diversification.
• To explore the interplay between sexual selection, molecular evolution, and life-history traits in predicting species richness.
• To test the hypothesis that sexual selection is a general driver of molecular evolutionary rates and diversification.

Main Methods:

• Analysis of sexual selection (measured by polygyny) across avian genera.
• Correlation of sexual selection metrics with rates of molecular evolution and body mass.
• Statistical modeling to predict species richness based on sexual selection, molecular evolution, and body mass.

Main Results:

• Sexual selection (polygyny) and the rate of molecular evolution positively correlate with the net rate of species diversification.
• These factors, particularly in combination, are crucial for explaining diversification in large-bodied avian taxa.
• Evidence suggests that mutation rates mediate some macroevolutionary effects of sexual selection.

Conclusions:

• Sexual selection is a significant driver of macroevolutionary diversification in birds.
• The rate of molecular evolution and body mass interact with sexual selection to shape species richness.
• Future research should leverage genomic data to further elucidate the macroevolutionary consequences of sexual selection.