A macroevolutionary study of historical contingency in the fanged frogs ofSoutheast Asia

The fanged frogs of South East Asia (50 species) show remarkable Variation in body size, reproductive mode and sexual dimorphism. This study examines the importance of a specialized, primitive trait, relative fang size, in co ntributing to this diversity. Relatively small fang size is found to have a significant association with the evolution of small body size, terrestrial reproductive modes, and sexual dimorphism where females are larger than ma les. These results support the idea of historical contingency or that prior historical events can exert a significant influence on subsequent patterns of evolutionary change. (C) 2001 The Linnean Society of London.