摘要：SummaryIntrogressive hybridization may play an integral role in local adaptation and speciation (). In the Mexican tetraAstyanax mexicanus, cave populations have repeatedly evolved traits including eye loss, sleep loss, and albinism. Of the 30 caves inhabited byA. mexicanus, Chica cave is unique because it contains multiple pools inhabited by putative hybrids between surface and cave populations (Mitchell et al., 1977), providing an opportunity to investigate the impact of hybridization on complex trait evolution. We show that hybridization between cave and surface populations may contribute to localized variation in traits associated with cave evolution, including pigmentation, eye development, and sleep. We also uncover an example of convergent evolution in a circadian clock gene in multiple cavefish lineages and burrowing mammals, suggesting a shared genetic mechanism underlying circadian disruption in subterranean vertebrates. Our results provide insight into the role of hybridization in facilitating phenotypic evolution.Graphical abstractDisplay OmittedHighlights•Hybridization leads to a localized difference in sleep duration within a single cave•Genomic analysis identifies coding differences in Cry1A across cave pools•Changes in Cry1A appear to be conserved in cavefish and burrowing mammalsAquatic science; Evolutionary biology; Aquatic biology
