Charles Darwin was an English naturalist and author best-known for his revolutionary theories on the origin of species, human evolution, and natural selection. A life-long interest in the natural world led Darwin to neglect his medical studies and instead embark on a five-year scientific voyage on the HMS Beagle, where he established his reputation as a geologist and gathered much of the evidence that fuelled his later theories.A prolific writer, Darwin s most famous published works include The Voyage of the Beagle, On the Origin of Species, The Descent of Man, and Selection in Relation to Sex, and The Expression of Emotions in Man and Animals. Darwin died in 1882, and in recognition of his contributions to science, is buried in Westminster Abbey along with John Herschel and Isaac Newton.

Stephen Jay Gould (1941-2002) was the Alexander Agassiz Professor of Zoology and Professor of Geology at Harvard University. He published over twenty books, received the National Book and National Book Critics Circle Awards, and a MacArthur Fellowship.

James A. Secord has served as Director of the Darwin Correspondence Project since 2006. He is Professor of History and Philosophy of Science at the University of Cambridge and a fellow of Christ's College. Besides his work for the Darwin Project, his research focuses on the history of science from the late eighteenth to the early twentieth centuries. His book, Victorian Sensation: The Extraordinary Publication, Reception, and Secret Authorship of Vestiges of the Natural History of Creation (2000), won the Pfizer Prize of the History of Science Society.