Creation, Evolution and Intervention: Which Theory is Correct? For many years, it has been widely debated how modern man came about. In this essay, I will explain the ideas of the three main theories: Evolution, Creation, and Intervention. I will also discuss which theory I believe and why it is that I believe it. Evolution Evolution, in biology, is the complex process by which organisms which originated on earth change because of changes in their environment and their function on earth. The earliest fossils ever discovered are from single celled organisms which resemble today's bacteria. People who believe in evolution believe t