How did the finch population change from before the drought to after? According to Figure 1, the average beak depth increased in size and the finch population had more finches with greater beak ...

But for the Grants, the rewards have been great: They have done nothing less than witness Darwin's theory of evolution ... winnowed certain finches harshly during a severe drought in 1977.

These findings suggest that, because of the links between beaks and song, an entirely new species of Darwin's medium ground finches could evolve in response to six major Galapagos droughts.

This morning came the talk that everyone had been waiting for - Princeton professors Peter and Rosemary Grant presented their 33-year project on the adaptive radiation of Darwin's finches on the ...