Adaptations

 When I was a kid, dinosaurs, especially my favorite, the deinonychus, looked very different. The idea that birds are dinosaurs was a fringe idea at the time, and no one thought they might have feathers. Now we know deinonychus most certainly did have feathers. We also know that they are very closely related to birds. A group of therian dinosaurs (raptors are a part of the therians) evolved  to lose their teeth and develop feathers which were capable of providing lift. This is an example of macroevolution, and it's a hard thing to study in action. Because of this, scientists tend to focus the majority of our observations on microevolution, or evolutionary changes within a species. The reason for this is we tend to live around a century at most currently, and macroevolution takes a long time. Microevolution is much easier to study, especially if you can find a short lived, heavily reproducing species such as the fruit fly. I remember these little guys took center stage in a lot of scenarios in my Genetics class I took last spring. A good example of microevolution is that some of them had white eyes, while some had red eyes. That is an evolution which took a small amount of time to develop because these insects are both short lived and reproduce in great numbers.