The book of Genesis, the first of the "Five Books of Moses" in the Hebrew Bible, has served as the explanation of the origin of the universe and all life for millions of people for over two millennia. According to this account, a single creator-god fashioned humans and every other living thing in all their complexity.
At the end of the European Middle Ages, Western tradition held that all of the world´s inhabitants had been created by God in one place, the Garden of Eden, soon after the formation of the earth. But as the scientific revolution began to unfold some 400 years ago, naturalists started to catalog fossils according to the layers in which they were found. Soon a very unexpected and troubling pattern emerged.
Fossils--remains or other traces of animals or plants preserved in rock--demonstrate the Earth's great antiquity. In background are insects preserved in amber (fossil resin) and the imprint of a fish. (See enlargements of each.) In foreground are a fossil trilobite (a type of arthropod, or segmented animal, that dates back to the Cambrian period--over 600 million years ago) and a fossilized piece of dinosaur bone.