In broad terms, finches. In specific terms, he observed how over time, the beak sizes and shapes of said finches changed to adapt to the food sources available.
I hope I was able to help. Best of luck.
Answer:
Gases, liquids and solids are all made up of atoms, molecules, and/or ions, but the behaviors of these particles differ in the three phases.
Explanation:
gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.