Speciation and reproductive isolation
Mechanisms of evolution · Biology
Study notes
Darwin's finches on the Galápagos: one ancestral species reached the islands, and isolation plus different foods split it into 15+ species — ground finches with crushing beaks, warbler finches with tweezer beaks. Mules show postzygotic isolation — horse-donkey hybrids are sterile. And apple maggot flies are splitting now: some prefer apples, some hawthorns — sympatric speciation in progress.