Charles Darwin'sOrigin of Speciesis one of the most widely cited books in modern science. Yet tackling this classic can be daunting for students and general readers alike because of Darwin's Victorian prose and the complexity and scope of his ideas.The "Origin" Then and Nowis a unique guide to Darwin's masterwork, making it accessible to a much wider audience by deconstructing and reorganizing theOriginin a way that allows for a clear explanation of its key concepts. TheOriginis examined within the historical context in which it was written, and modern examples are used to reveal how this work remains a relevant and living document for today.In this eye-opening and accessible guide, David Reznick shows how many peculiarities of theOrigincan be explained by the state of science in 1859, helping readers to grasp the true scope of Darwin's departure from the mainstream thinking of his day. He reconciles Darwin's concept of species with our current concept, which has advanced in important ways since Darwin first wrote theOrigin, and he demonstrates why Darwin's theory unifies the biological sciences under a single conceptual framework much as Newton did for physics. Drawing liberally from the facsimile of the first edition of theOrigin, Reznick enables readers to follow along as Darwin develops his ideas.The "Origin" Then and Nowis an indispensable primer for anyone seeking to understand Darwin'sOrigin of Speciesand the ways it has shaped the modern study of evolution.