Wind because its not mechanically eroding them..
Due to divergent evolution, some species may have similar anatomical structures with the same purposes. The species while not exactly similar are close enough to allow the interbreeding of the two, such as the horse and mule
Answer:
I'm pretty sure the answer is 4.
Explanation:
1 and 2 are definitely homeostasis because it is a way to keep your body balanced how it needs to be and 3 would be a natural reaction that your body would make to prevent further pain, but 4 would be a personal choice that is made by the person who stays up.
