Ecological and landscape effects on genetic distance in an assemblage of headwater fishes

摘要: Environmental divergence along hierarchically structured longitudinal gradients may constitute barriers to gene flow in river networks for headwater specialised species. While known, this phenomenon has not been well studied, especially with regard degree of specialisation. We examined six species that differ habitat specialisation assess whether patterns differentiation vary according geographic or environmental distance. also identified regional anthropogenically induced fragmentation effects by comparing within-drainage genetic distance across replicate watersheds. used a comparative modelling framework determine isolation resistance large habitats was better predictor The influence reservoir presence and network characteristics the hydrology size were assessed. Resistance from rivers closely related specialisation, increased leading loss drainagewide population connectivity. These results affirm dendritic naturally fragment Further anthropogenic detected two drainages, indicating interactions system-specific conditions. Landscape variables affected predicted ways, supporting importance genetically structuring drainage networks.