Neophytes may promote hybridization and adaptations to a changing planet

Abstract

AbstractHuman activities erode geographic barriers, facilitating hybridization among previously isolated taxa. However, limited empirical research exists on the consequences of introduced species (neophytes) for hybridization and subsequent evolutionary outcomes. To address this knowledge gap, we employed a macroecological approach. First, we examined the spatial and phylogenetic overlap between neophytes and hybrids by integrating the Plants of the World Online database with the Global Naturalized Alien Flora database. Second, leveraging the largest dated plant phylogeny available, we compared diversification rates between genera containing hybrids and neophytes versus those without. Third, focusing on the extensively studied hybrid flora of Britain, we studied the spatial distributions of hybrids in relation to neophyte and native parents, assessing potential adaptations to anthropogenic disturbances and impacts on native species. Overall, our findings highlight positive ties between contemporary biodiversity redistribution and hybridization. Spatially (across countries) and phylogenetically (across genera), neophyte incidence was positively associated with hybrid incidence. Genera comprising both hybrids and neophytes displayed significantly higher diversification rates. Neophyte hybrids primarily occupied areas with a higher human footprint, with limited evidence of hybrids threatening native species throughout their range in more natural habitats. These results challenge the notion that species naturalizations and hybridizations exclusively yield negative outcomes for biodiversity. While it is conceivable that anthropogenic hybridization may facilitate recombination of genetic variation and contribute to conserving genetic diversity in disturbed environments, further research is needed to fully understand these processes.