Dispersal Enhances Abiotic Adaptation in Populations Under Interspecific Competition Compared to Isolation

ABSTRACT Interspecific competition is known to hinder evolutionary adaptation by limiting resource availability and reducing genetic diversity. In contrast, dispersal has been hypothesized to mitigate these limitations by increasing genetic variation and promoting gene flow. Here, we investigated how dispersal influences abiotic adaptation in the presence and absence of interspecific competition using two bacterial species, Escherichia coli and Pseudomonas fluorescens . Populations were cultured under monoculture and coculture conditions across three temperatures, with and without dispersal. Our results revealed that dispersal significantly enhanced abiotic adaptation in populations in competitive environments, particularly in numerically inferior populations, facilitating persistence under warmer conditions. Dispersal also prevented extinction events observed in cocultures without dispersal, highlighting its role in population persistence. These findings underscore the importance of adaptation to global warming, particularly for inferior species.