Publisher
Royal Society Publshing
Abstract
Hybridization plays a complicated and oft-misunderstood role. Once deemed unnatural and uncommon, hybridization is now recognized as ubiquitous among species. But rates of hybridization and introgression at the community level (i.e., hybrids within and among localities) are poorly understood despite the relevance to ecology, evolution, and conservation. We examined hybridization across 75 freshwater fish communities within the Ozarks (USA) by genotyping 33 species (N=2,865 individuals) using restriction-site associated DNA sequencing (ddRAD). We found evidence of hybridization (70 individuals; 2.4%) among 18 species pairs involving 73% (24) of species analyzed, with the majority being concentrated within a single family (Leuciscidae/minnows; 15 species; 66 individuals). Introgression was evident from 24 backcrossed individuals involving 10/18 species pairs, providing evidence for genetic exchange among species. Hybrids occurred within 42/75 communities (56%). Random forest classification identified four variables (species richness, protected area extent, and precipitation [May and annually]) exhibiting 73-78% accuracy in predicting hybrid occurrence. Although hybrids were mainly restricted to just one family, our community-level assessment suggested that hybridization is spatially widespread and influenced by environmental factors. In contrast to more conventional single species-pair evaluations, our approach tested a wide breadth of species pairs and provided a more holistic survey of natural hybridization.
Year
2023
Category
Refereed journal