Former children's television host and scientist Bill Nye recently captured national media attention when he blasted Americans who believe in creationism and reject Darwin's theory of evolution.

The scientific concept of evolution holds that each species on Earth developed from a process of natural selection acting on random genetic mutation.

Obviously there's loads of scientific evidence that supports evolution. But we wanted to understand the main contentions.

First, there are several different varieties of creationists.

Traditional creationists believe that the universe was created by God.

A separate theory, called Intelligent Design, is one of the more sophisticated alternative theories to evolution, well-known for its support from Lehigh University biochemist Michael Behe. Intelligent Design does not dispute the definition of evolution as "change over time" or, for the most part, that living things are related by common ancestry. However, this group does believe that the natural world is too complex and diverse to have occurred through random processes.

The Discovery Institute, a religious think tank that advocates the theory of Intelligent Design, outlines their own findings of scientific weakness in modern evolutionary science.

We'll follow up with refutations of these "scientific" claims.