Mixed outcomes in recombination rates after domestication: Revisiting theory and data

The process of domestication has altered many phenotypes. Selection on these phenotypes has long been hypothesized to indirectly select for increases in recombination rate. This hypothesis is consistent with theory on the evolution of recombination rate, but empirical support has been unclear. We review relevant theory, lab-based experiments, and data comparing recombination rates in wild progenitors and their domesticated counterparts. We utilize population sequencing data and a deep learning method to infer genome-wide recombination rates for new comparisons of chicken/red junglefowl, sheep/mouflon, and goat/bezoar. We find evidence of increased recombination in domestic goats compared to bezoars, but more mixed results in chicken, and generally decreased recombination in domesticated sheep compared to mouflon. Our results add to a growing body of literature in plants and animals that finds no consistent evidence of an increase in recombination with domestication.