A recent study by researchers at the University of East Anglia suggests that allowing females to mate with multiple males could help reduce harmful genetic mutations and lower the risk of extinction for species. The findings, published in the Proceedings of the National Academy of Sciences, were based on a 15-year experiment involving thousands of red flour beetles. Scientists compared beetle populations where females mated with only one male to those where females had the opportunity to mate with several males in a competitive setting. After 156 generations, populations exposed to stronger sexual selection—where males competed more intensely for mates—had significantly fewer harmful genetic mutations. The study attributed this reduction to the fact that females had more choices in mates, and males had to compete more to reproduce. In one group of beetles, females could mate with up to five males per generation, while in the other, each female was paired with just one male. Researchers sequenced the genomes of beetles from both groups and found that the populations with more mating options had fewer harmful mutations, while maintaining similar overall genetic diversity. This supports the "good genes" hypothesis, which suggests that successful males tend to have the best genetic traits, including fewer harmful mutations. When females can choose among competing males or when males compete intensely for mates, those with poorer genetic health are less likely to pass on their genes. This process acts like a natural quality-control mechanism, helping to eliminate harmful genetic variants from the population. Surprisingly, this genetic filtering did not reduce overall genetic diversity. Earlier concerns had suggested that strong sexual selection might shrink the breeding population and lower genetic diversity, but the study found that beetles under stronger sexual selection retained similar levels of genome-wide diversity to those in the less competitive group. Senior author David Richardson noted that many endangered species face challenges like small population sizes and inbreeding, which can lead to the expression of harmful mutations and increased extinction risk. The study suggests that conservation efforts—whether in the wild or in captivity—should consider restoring natural levels of sexual selection. Allowing females to mate with multiple males could help populations naturally eliminate harmful genetic variants and improve their long-term survival. The research also aimed to explain why sexual reproduction remains common despite its costs, suggesting that sexual selection helps populations rid themselves of harmful mutations. The competition for mates, it seems, may play a crucial role in the fight against extinction.