What is it about?
We show that females which are provided with multiple males to mate with (more sexual selection), as opposed to just one, produce offspring containing fewer harmful genetic mutations. In turn, this helps small populations get rid of harmful mutations without reducing the overall amount of genetic diversity they harbour. Importantly, when these populations were reduced in size and inbred (i.e. mimicking what may occur in an endangered population), those that had experienced more sexual selection - and thus contained fewer harmful mutations - were less likely to go extinct.
Featured Image
Photo by Romi Yusardi on Unsplash
Why is it important?
Put simply, evolution happens when certain individuals have more offspring than others. This can happen because some individuals are better able to make it to reproductive age - classic survival of the fittest - but even among those that survive, competition and mate choice mean that not every individual has the same number of offspring - this is sexual selection in action. Harmful genetic mutations always occur over generations in all organisms, and their accumulation can reduce the genetic health of individuals and populations. Our study provides direct genomic evidence that sexual selection can help purge these mutations (and thus increase population genetic health) while maintaining overall genetic diversity, which is crucial for a population to adapt to future challenges. This suggests that allowing more natural mating competition (e.g. males competing to mate with females) and mate choice (i.e. females choosing which male(s) to mate with) would greatly benefit many small or endangered populations. This study is important for two main reasons. First, it provides evidence that may help explain the widespread prevalence of sexual selection and sexual reproduction in nature, despite the inherent costs associated with these mechanisms. Second, it has important ramifications for how we manage populations of conservation concern, whether in the wild or captivity. For example, it may change how we manage the breeding of endangered species in zoos etc.
Perspectives
This article is the culmination of the work of many people over more than twenty years. It's great to be able to turn all that effort into science that could help us manage endangered populations and contribute to biodiversity conservation.
Michael Pointer
University of East Anglia
Read the Original
This page is a summary of: Sexual selection purges mutation load, but not overall genetic diversity, decreasing vulnerability to extinction, Proceedings of the National Academy of Sciences, September 2026, Proceedings of the National Academy of Sciences,
DOI: 10.1073/pnas.2608675123.
You can read the full text:
Contributors
The following have contributed to this page
