question: What provides clear evidence of evolution?
distractor3: mutations
distractor1: biologists
distractor2: extinction
correct_answer: fossils
support: Fossils are a window into the past. They provide clear evidence that evolution has occurred. Scientists who find and study fossils are called paleontologists . How do they use fossils to understand the past? Consider the example of the horse, shown in the Figure below . The fossil record shows how the horse evolved.