Biologists in darwins time had already begun to understand that living things chang overtime how did darwin contribute to these ideals

Darwin as a young man traveled to many areas to study animals and such but he came across a bird that looked like is own and so he compared them and found that his old bird that was given to him was much older and so that's how he contributed to these ideas

He went to a island where there were different kinds of finches but they were not native to the land but they had adapted to their eviroment