Explain why and how theories may be changed or replaced over time.

Science is always changing and due to this new evidences discovered and theories will be updated and changed.

Explanation:

A theory can change or update with the time. There is no theory which can be consider as the absolute truth. A theory which is useful has been tested by the scientists and give the conclusion about that theory on which majority of scientists agree.

As known that science is a field which always changing with time. Whenever a new evidence is discovered then after that the theory might be change or it will be updated.