Chapter 2 of the video gives a history of Darwin's work in the two decades previous to writing his book "On the Origin of Species" in 1859. His voyage to the South American Galapagos Islands is recalled, where he marveled over hundreds of specimens of plants and animals. He was particularly interested in the birds of the islands and their varying characteristics. Upon his return to England he found that these birds were actually finches, even though their characteristics were not consistent with finches he had observed in the past. It was upon this research that he introduced his theory of natural selection in which new species could develop from old species, also called descent with modification. In other words, all organisms could be represented by a tree of life where all descended from a common ancestor. The video then takes the viewer back to Dover, where the textbook controversy continues. In order to present more information to students, the school board discusses adopting a textbook that presents both evolution and creationism as theories to the origin of life.