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

Most loci under balancing selection are undetectable by standard genome scans, with only a biased subset showing large, symmetrical fitness effects.

• Why it matters: Understanding the true prevalence of balancing selection is crucial for insights into genetic diversity and evolutionary processes, but current detection methods may underestimate it.
• 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.
• The result: Findings reveal that a significant portion of loci remain hidden from detection, especially in species like Drosophila melanogaster, highlighting limitations in current methods and the potential ubiquity of balancing selection.