Recurrent patterns of natural selection in a population of Darwin's finches

摘要: The adaptive significance of morphological traits can be assessed by measuring and identifying the forces selection acting on them. Boag Grant documented directional in a small population Darwin's medium ground finches, Geospiza fortis, I. Daphne Major, Galapagos, 1977. Large beak body size were favoured at time diminishing food supply high adult mortality. We show here that two subsequent periods moderate to mortality (1980 1982), was subject same selection. have used recently developed technique ascertain targets direct Beak depth weight commonly under increase but, surprisingly, width directly selected decrease, over all three results implications for our understanding evolutionary change finches.