Answer: Beaks---->Evolution, Natural Selction, Genetic Drift, Behavioral Isolation, n Non-random mating...
Explanation:
Darwin observed many discoveries like the Galapagos tortoises, iguanas, penguins, crabs, etc...But one of the most important ones that definitely helped to see the evolution and the process of natural selection is the Galapagos finches they changed a lot mainly because of environmental changes. The Galapagos Islands are special to evolutionary history firstly because there are a lot of different sizes and colors in birds but the main focus was that after Earth was a Pangea, all land united, genetic drift occurred in the Galapagos island meaning that a small population was 'trapped' inside with no way of getting new traits though that's not exactly right because we not only change genetically but also by environmental changes and humans change it too of course(like hunting). Another important discovery that was found there wasn't only hints of evolution and natural selection but also behavioral changes especially in mating, some birds sing or dance it really depends but if some animals don't mate then new species are formed that's one of the reasons why it created a lot of diversity; Another reason to the topic of reproduction is non-random mating, some organisms are looking for some specific location or phenotypes in their mates if they don't find it they look for them in their own species which can cause the extinction of that species or spread it.
