The wide red beak comes from a black base on the bird ... you have a higher chance of seeing the birds inland. The Long-tailed Finch is an Australian gray bird whose head looks very comical ...

So the adaptation to a changed environment led to a larger-beaked finch population in the following generation. Adaptation can go either way, of course. As the Grants later found, unusually rainy ...

How do you know that finches' beak depth is heritable? You can see from Figure 2 that there is a correlation between the parents' and offsprings' beak size. How did the finch population change ...