Since their time, many new discoveries have been made supporting the theory, including new knowledge of genetics and the chemical process of heritability. But since the biological theory of evolution depends on scientific observations, which scientific finding, if it was ever made, would force scientists to radically change the theory? A. if a very famous scientist decided she did not like the theory B. if modern animal fossils were ever found in a very ancient geologic period C. if an animal's circulatory system was shown to be very complex D. if a very ancient species of animal was found to still be alive today

If modern animal fossils were ever found in a very ancient geologic period, it would have changed the whole evolutionary theories.

Option B.

Explanation:

Evolution as an event, is very slow and gradually progressive movement. It took millions of years for the unicellular bacteria to evolve and finally make the modern day humans. But the process isn't a haphazard and the evolution processes are well understood by humans. A scientist can clarify how the cell systems became complex to eukaryotic cells, the tissues began to develop, and then the organs and the organ system. The systems like circulatory system, nervous system, muscles, everything slowly grew to evolve animals into a superior one. This is the theory in present days and this is supported by Fossils and different other proofs.

But if one day, a fossil is found which is actually the fossil of a modern animal in very ancient time, its not collaborative with the theories. Modern day animals are born as a result of huge evolutions and presence of them in very ancient times is impossible. So this finding can wipe out present day theories of evolution.