River networks function as conduits for water and sediment transport across Earth's landscapes, while the elevated boundaries separating these networks, termed drainage divides, determine the partitioning of material fluxes among adjacent basins and establish physical barriers that restrict biotic dispersal. Variations in tectonics, climate, and lithology can alter the position of these divides, influencing water balance, erosion rates, sediment flux, and the geographic connectivity and evolutionary trajectories of biota. This study focuses on the overlooked temporal evolution of 'wind-gaps' (i.e. old river valleys transformed into in-valley drainage divides by drainage capture events) as an unstudied but key capture-related landform hypothesised to be fundamental in shaping post-capture-related landscape evolution. Using numerical landscape evolution modelling, our findings challenge the prevailing perception of wind-gaps as static landforms, revealing previously unrecognised mobility, with wind-gaps serving as mobile divides that reshape entire landscapes. Moving wind-gaps can trigger cascading morphological and erosional changes beyond an initial capture event, initiating a domino effect of captures of lateral tributaries to the pre-capture river. This can repeatedly alter the connectivity of riverine ecosystems, driving complex but predictable patterns of biotic diversification and leaving abiding imprints in the sedimentary and landscape records. Wind-gap propagation offers a mechanistic framework that opens avenues for deciphering complex linkages over time between landscape evolution, sediment dynamics, and biodiversity.