It took Charles Darwin more than twenty years to publish this book, in part because he realized that it would ignite a firestorm of controversy. The Origin of Species first appeared in 1859, and it remains a continuing source of conflict to this day. Even among those who reject its ideas, however, the work's impact is undeniable. In science, philosophy, and theology, this is a book that changed the world. In addition to its status as the focus of a dramatic turning point in scientific thought, On the Origin of Species stands as a remarkably readable study. Carefully reasoned and well-documented in its arguments, the work offers coherent views of natural selection, adaptation, the struggle for existence, survival of the fittest, and other concepts that form the foundation of modern evolutionary theory. ABOUT THE AUTHOR: Charles Robert Darwin, FRS was an English naturalist and geologist, best known for his contributions to evolutionary theory. He established that all species of life have descended over time from common ancestors, and in a joint publication with Alfred Russel Wallace introduced his scientific theory that this branching pattern of evolution resulted from a process that he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. Darwin published his theory of evolution with compelling evidence in his 1859 book On the Origin of Species, overcoming scientific rejection of earlier concepts of transmutation of species. By the 1870s the scientific community and much of the general public had accepted evolution as a fact. However, many favoured competing explanations and it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed in which natural selection was the basic mechanism of evolution. In modified form, Darwin's scientific discovery is the unifying theory of the life sciences, explaining the diversity of life.