Sex-dependent selection, ageing, and implications for "staying alive".

Area of Science:

• Evolutionary biology
• Gerontology
• Sex differences in aging

Background:

• The "staying alive" hypothesis suggests traits evolve to maximize survival and reproduction.
• Male extrinsic mortality (external factors like predation) is often higher than female extrinsic mortality.
• Understanding the interplay between extrinsic mortality and aging is crucial for evolutionary theory.

Purpose of the Study:

• To explore how higher male extrinsic mortality influences selection against aging-related diseases.
• To investigate the potential for female-biased longevity as an incidental consequence of male mortality patterns.
• To propose a framework for testing this against adaptive self-preservation hypotheses.

Main Methods:

• Theoretical modeling integrating concepts from ageing biology and evolutionary theory.
• Comparative analysis of mortality patterns across species.
• Developing testable predictions for empirical research.

Main Results:

• Higher male extrinsic mortality can relax selection against late-acting, age-related diseases.
• This relaxation may lead to increased intrinsic mortality in males.
• Consequently, traits promoting longevity in females could arise incidentally, not solely through direct selection for self-preservation.

Conclusions:

• The proposed mechanism offers a novel perspective on sex differences in longevity.
• Empirical validation is needed to distinguish this incidental trait evolution from adaptive self-preservation.
• Integrating ageing biology with evolutionary hypotheses can yield new insights into lifespan determination.