1) According to the diagram, divergence among mammals took place about 75 mya.
2) Scientists are able to determine common ancestors by studying molecular data.
3) Darwin's theory of evolution by natural selection states that animals change over long periods of time.
4) Scientists are closesly studing how genes reorganize themselves.
5) Some scientists, however, think new species evolve quickly.
6) Still, among scientists, the principles of natural selection remain unchanged and highlight how animals evolve.
7) The main tool for the study of evolution is careful observation of fossils and the anatomy of animals.
8) Scientists also study animal embryology.
9) What no one doubts is the wide diversity among organisms on Earth.
10) The divergence that took place among mammals helps us understand why whales and dolphins are mammals and not fish.
Fun fact: Uh, I happen to discover a whole packet of answer keys, not just for this but also for other assignments and stuff. (O.O)
