The Scientific Evidences of Organic Evolution

George John Romanes gathers the case for organic evolution into a short scientific essay intended for readers with limited time. Beginning with natural selection, he explains how inherited variations and changing conditions can gradually alter plants and animals. His comparison with the work of gardeners and livestock breeders makes the process concrete. The preface describes a lecture later revised for publication at Darwin's urging.

The argument then draws on classification, bodily structure, geology, geographical distribution and embryology. In the discussion of distribution, Romanes considers why island species resemble those of nearby continents and why fossils share regional characteristics with living animals. He also examines the logic of choosing a natural explanation for apparent design. Readers interested in the history of biology can follow how a nineteenth-century writer arranged several kinds of evidence into a connected defence of evolutionary theory.