Population size interacts with reproductive longevity to shape the germline mutation rate

Area of Science:

• Evolutionary biology
• Genetics
• Molecular biology

Background:

• Mutation rates exhibit vast diversity across life.
• Large effective population sizes and rapid reproduction correlate with lower mutation rates.
• DNA repair efficacy is crucial for maintaining genomic stability.

Purpose of the Study:

• To investigate the influence of generation time on germline mutation rates and DNA repair efficacy.
• To explore the interplay between reproductive age, mutation accumulation, and selection pressures.
• To reconcile the observed variation in mutation rates with evolutionary theory.

Main Methods:

• Theoretical modeling of selection pressures on mutation rates.
• Empirical analysis of germline mutation rates across species.
• Comparative genomics and evolutionary analysis.

Main Results:

• Longer generation times intensify selection for reduced germline mutation rates.
• Species with longer reproductive lifespans exhibit more effective DNA repair in germ cells.
• Mutation accumulation during embryonic development is less dependent on generation time.

Conclusions:

• A longer generation time amplifies selection for enhanced DNA proofreading and repair in germ cells.
• Counterintuitively, species with higher per-generation germline mutation rates may possess superior DNA repair mechanisms.
• These findings have implications for understanding genome evolution and aging across species.