Convergent adaptive radiations in Madagascan and Asian ranid frogs reveal covariation between larval and adult traits

摘要

Recent studies have reported that independent adaptive radiations can lead to identical ecomorphs. Our phylogenetic analyses of nuclear and mitochondrial DNA sequences here indicate that a major radiation of ranid frogs on Madagascar produced morpho- logical, physiological, and developmental characters teat are re- markably similar to those that independently evolved on the Indian subcontinent. We demonstrate further that, in several cases. adult and larval stages each evolved sets of characters which are not only convergent between independent lineages, but also' allowed both developmental stages to invade the same adaptive zone. It is likely that such covariations are produced by similar selective pressures on independent larval and adult characters rather than by genetic or functional linkage. We briefly discuss why larval/adult covariations might constitute an important evolution- ary phenomenon in species for which more than one develop- mental stage potentially has access to multiple environmental conditions.