What difference did darwin notice among the finches

He saw that they all had different sizes and shape beaks, he believed that they adapted to their environment. In one place the finches had huge beaks especially made for cracking nuts. In another they could have shorter and thinner beaks made to eat insects off the ground like worms. 
Darwin found evidence for evolution! 
:)

They were different colors, sizes, etc. which brought his theory that all animals have different characteristics which makes them unique in their own way.