Dispersal is a complex and evolutionarily important phenotype that integrates behavioural, physiological, genetic, and ecological processes across its three major stages: departure, transfer, and settlement. Rather than representing a random subset of individuals, dispersers frequently differ from residents in personality traits such as boldness, exploration, aggression, risk-taking, and sociability, giving rise to personality-dependent dispersal syndromes. Increasing evidence indicates that dispersal has a substantial genetic component and is generally governed by a polygenic architecture, with candidate genes and molecular pathways associated with circadian regulation, neurobiological function, locomotor performance, and other physiological processes. The expression and evolutionary consequences of dispersal are strongly context-dependent, reflecting interactions between genetic variation, environmental conditions, habitat dynamics, and life-history trade-offs. Dispersal also co-evolves with social behaviour and can generate persistent behavioural and social polymorphisms within populations. At the population level, variation in dispersal directly influences gene flow, kin structure, genetic diversity, inbreeding, population differentiation, colonization, and local adaptation. Anthropogenic habitat modification can further alter dispersal phenotypes and their genetic consequences, demonstrating that changes in landscape dynamics may generate substantial eco-evolutionary effects. Overall, dispersal should be regarded not simply as movement between populations, but as an integrated behavioural and genetic trait whose evolution can reshape both individual fitness and population genetic structure. Understanding these interactions requires approaches that combine behavioural ecology, quantitative genetics, molecular genomics, demography, and environmental context.
