Ecology and allometry predict the evolution of avian developmental durations

Area of Science:

• Evolutionary Biology
• Comparative Physiology
• Ornithology

Background:

• Developmental duration is a key life-history trait with diverse evolutionary drivers.
• Understanding the factors influencing developmental timing is crucial for evolutionary biology.

Purpose of the Study:

• To investigate the mechanistic and ecological factors driving the evolution of developmental duration in avian species.
• To assess the relative contributions of growth, evolutionary history, body size, and ecological variables to developmental duration.

Main Methods:

• Analyzed embryological data, incubation, and fledging periods for 3096 avian species.
• Utilized comparative methods to test mechanistic and ecological hypotheses.
• Examined correlations between developmental duration and environmental/phenological factors.

Main Results:

• Growth-related developmental phases are the longest and most variable, suggesting allometric constraints.
• Deep evolutionary history significantly influences developmental durations.
• Body size explains less variation in developmental duration than previously assumed.
• Environmental safety and breeding phenology pressures correlate with developmental durations.

Conclusions:

• Developmental duration is shaped by a combination of mechanistic (growth constraints), evolutionary (phylogeny), and ecological (environment, phenology) factors.
• These findings offer broad insights into the diversification of a fundamental life-history trait.
• The study highlights the interplay of constraints in shaping evolutionary trajectories.