The answer is first to last with the labels going in and out of order to get an explanation
The trophi are responsible for crushing food
Answer:
c. Directional selection
Explanation:
There are three types of selection: stabilizing, directional and disruptive. Currently seed cracker finches show disruptive selection with respect to bills. In disruptive selection two extreme phenotypes are preferred in population over the mean phenotype. Here either, small or large bills are beneficial for birds so it is an example of disruptive selection.
If due to some climatic change all seeds would become hard, it would be more beneficial for birds to have large bills. Slowly nature will select for birds with large bills rather than birds with small bills. The selection now will shift to directional selection since only one of the extreme phenotypes is being favoured.
The answers are; geographical isolation and temporal isolation.
In temporal isolation, because the different species have different mating seasons, so even though their habitats overlap, they do not interbreeding is rare. Geographical isolation also plays a role because the different species are found predominantly in different sites during breeding, some in the woodland, some in the lowlands and others in streams.
