In On the Origin of Species (1859), Charles Darwin presented his evidence for evolution and natural selection as its mechanism. He drew upon his earliest data gathered during his voyage on the HMS Beagle, which included collecting mammalian fossils in South America clearly related to living forms, tracing the geographical distributions of living species across South America, and sampling the peculiar fauna of the geologically young Galapagos Archipelago that showed evident affinities to South American forms. By the end of the voyage, he came to the realization that instead of various centers of creation, species evolved in different regions throughout the world. However, except for some personal ponderings, he did not express this revelation explicitly in his notebooks until shortly after his return. Over the years, he collected more evidence supporting evolution, but his early work remained paramount: it became the first paragraph of On the Origin of Species and encompassed three separate chapters, as well as later appearing in his autobiography.
Many discussions of Darwin's landmark book give scant attention to this wealth of evidence and today we still do not fully appreciate its significance in Darwin's thinking. In Origins of Darwin's Evolution, J. David Archibald explores this lapse. He also shows that Darwin's other early passion, geology, proved a more elusive corroboration of evolution. On the Origin of Species dedicated only one chapter to the rock and fossil record, as it appeared too incomplete for Darwin's evidentiary standards. Carefully retracing Darwin's gathering of evidence and the evolution of his thinking, Origins of Darwin's Evolution achieves a new understanding of how Darwin crafted his transformative theory.