Marking the 150th anniversary of the publication of On the Origin of Species, this program shows how Charles Darwin developed his theory of evolution and explores its ramifications in today's scientific community. Renowned natural history interpreter David Attenborough travels the globe, examining fresh evidence for Darwinian thought and illustrating why it is more relevant than ever. Viewers encounter findings from a wide range of disciplines, including paleontology, biogeography, anatomy, and embryology, as well as early controversies surrounding the study of plate tectonics. Spectacular wildlife footage reveals fascinating animal behavior and helps depict the theory that changed the world's thinking. A BBC/Open University Co-production.