The Herring Gull Complex (Larus argentatus - fuscus - cachinnans) as a Model Group for Recent Holarctic Vertebrate Radiations

摘要: Under what circumstances speciation in sexually reproducing animals can occur without geographical disjunction is still controversial. According to the ring species model, a reproductive barrier may arise through “isolation-by-distance” when peripheral populations of meet after expanding around some uninhabitable barrier. The classical example for this kind herring gull (Larus argentatus) complex with circumpolar distribution northern hemisphere. An analysis mitochondrial DNA variation among 21 taxa indicated that members differentiated largely allopatry following multiple vicariance and long-distance colonization events, not primarily “isolation-by-distance”.