Characterizing the detectable and invisible fractions of genomic loci under balancing selection.

Most loci under balancing selection are likely invisible to genome scans, with detectable loci showing large, symmetrical fitness effects, especially in Drosophila-like species.

• Why it matters: Understanding the true prevalence of balancing selection is important because current methods may underestimate how common it is across genomes, affecting evolutionary insights.
• What they did: Using analytical models and population genetic simulations, the study estimates the proportions of detectable versus invisible loci under balancing selection across different species and parameters.
• The result: Findings suggest that a large fraction of loci under balancing selection remain undetectable, and detection power varies significantly between species like Drosophila melanogaster and humans, limiting our understanding of its prevalence.