Strategies for the evolution of sex

Area of Science:

• Evolutionary Biology
• Population Genetics
• Theoretical Biology

Background:

• The Jan, Stauffer, and Moseley hypothesis proposed sex as a strategy to avoid extinction caused by accumulating deleterious mutations.
• Previous models focused on the necessity of this hypothesis for the evolution of sexual populations in finite environments.

Purpose of the Study:

• To investigate whether the Jan, Stauffer, and Moseley hypothesis is the sole driver for the evolution of stable sexual populations.
• To explore alternative mechanisms, such as a finite conversion probability to sex, that could lead to stable sexual populations.

Main Methods:

• Theoretical modeling of sexual population dynamics in a finite population.
• Analysis of the role of deleterious mutation load and conversion probability to sex.
• Identification of phase transitions and different steady-state regimes.

Main Results:

• The hypothesis of escaping extinction is sufficient but not necessary for stable sexual populations.
• A finite probability of conversion to sex can independently establish a stable sexual population, given an upper limit on deleterious mutations.
• Phase transitions to multistable and intermittent regimes occur with high conversion probabilities, and a different steady state emerges with slow drive.

Conclusions:

• The evolution of sex is more flexible than previously suggested, with finite conversion rates offering an alternative pathway to stable sexual populations.
• Deleterious mutation accumulation and conversion probability interact to shape population dynamics, leading to diverse evolutionary outcomes.
• Understanding these mechanisms is crucial for comprehending the persistence of sexual reproduction in finite populations.