Abstract
To examine the role of natural selection in fecundity in a variety of Caenorhabditis elegans genetic backgrounds, we used an experimental evolution protocol to evolve 14 distinct genetic strains over 15–20 generations. The dataset generated 790 genealogies analyzing reproductive fitness and timing across wild-type and mutant strains with targeted mutations in specific pathways. Selective effects on fecundity were strongest in early generations, while reproductive timing showed longer-term negative selection patterns.