Disruptive selection and the genetic basis of bill size polymorphism in the African finch Pyrenestes

摘要: MECHANISMS producing and maintaining discrete polymorphisms have long fascinated evolutionary biologists1,2. Despite the ubiquity of non-sex-limited in vertebrates, factors them are well understood only a few instances3. The African finch Pyrenestes is unique among birds exhibiting non-sex-determined polymorphism bill size4,5. Morphs breed randomly with respect to size differ diet feeding performance on soft hard seeds4,6. I present here: (1) new data showing that appears result from single genetic factor; (2) support long-term field studies for earlier suggestions disruptive selection acting size; (3) revealing presence possible third, much larger morph. Results suggest may arisen through mutations, where morphs occupy distinct adaptive peaks differences seeds differing hardness.