Charles Darwin is taken aback when he receives a manuscript from a colleague, Alfred Wallace, which contains many of the same conclusions as he on evolution and the development of various species. Darwin's theory was developed over a great many years and in flashbacks, the manner in which it developed is shown. He had many supporters and likely more critics. He knew that his ideas were radical and that they would conflict with religious thought on the subject of creation. In reviewing his thoughts however, he realizes that he can without much difficulty claim to have been the first to develop the theory. These events spur him on to publish his findings in his now famous book. Written by garykmcd