A Dual Role for Sex?

TL;DR

This paper demonstrates that sexual reproduction in yeast can both remove harmful mutations and enable rapid adaptation, showing sex has a dual role contrary to previous theories.

Contribution

The study develops evolutionary models showing that sex can both purge mutations and facilitate adaptation, revealing a dual role for sexual reproduction.

Findings

Sexual reproduction purges deleterious mutations in static environments.

Sexual reproduction enables faster adaptation in changing environments.

Sex serves a dual role, combining mutation purging and adaptive benefits.

Abstract

The two classic theories for the existence of sexual replication are that sex purges deleterious mutations from a population, and that sex allows a population to adapt more rapidly to changing environments. These two theories have often been presented as opposing explanations for the existence of sex. Here, we develop and analyze evolutionary models based on the asexual and sexual replication pathways in Saccharomyces cerevisiae (Baker's yeast), and show that sexual replication can both purge deleterious mutations in a static environment, as well as lead to faster adaptation in a dynamic environment. This implies that sex can serve a dual role, which is in sharp contrast to previous theories.