Answer:
in fossils we see homologous structures that suggest a common ancestor.
By looking at the bones of the arms and comparative anatomy we see the similar structure and function that is retained.
When looking at other animals like birds we see Analogous structures that look similar but have a different function (flying).
Finally we see Vestigial structures which are structure that no longer function as they once were used for. An example of this is the coccyx (tail bone in humans) compared to tails in dogs, cats, monkeys, etc.
Step-by-step explanation: