Tracing the evolution of Charles Darwin’s thoughts about evolution is becoming an increasingly accessible project, thanks to a growing cache of publicly available digitized Darwin manuscripts on the American Museum of Natural History’s Web site. As of the 155th anniversary of the publication of Charles Darwin’s On the Origin of Species on November 24, 2014, the Museum’s Darwin Manuscripts Project had made available 12,000 high-resolution and color images of manuscript pages, drawings, book abstracts, and other writings, complete with transcriptions that decipher the famous naturalist’s handwriting. By June 2015, the Museum will host more than 30,000 digitized documents written by Darwin between 1835 and 1882.

“These notebooks, marginalia, portfolios and abstracts were the basis for eight of Darwin’s books, beyond the Origin, that set down, enlarged and defended the theory of evolution by natural selection,” said Darwin Manuscripts Project Director David Kohn. “In these writings, you can see Darwin as a thinker, a keen-eyed collector, an inspired observer, and a determined experimenter.”

The Darwin Manuscripts Project has been publishing Darwin’s writings since 2007, but the publication and interpretation of the entire corpus will make it possible for visitors to trace the gradual gestation and long maturation of Darwin’s theory of evolution by natural selection. The project involves a close collaboration with Cambridge University Library, which holds Darwin’s archives, and the Darwin Correspondence Project. Content is being simultaneously published by the Cambridge Digital Library.

The 12,000 documents accessible on the site now cover the 25-year period in which Darwin became convinced of evolution; discovered natural selection; developed explanations of adaptation, speciation and a branching tree of life; and wrote the Origin.

“Darwin’s work in creating the Origin of Species encompassed much more than just setting pen to paper and writing the epochal book,” Kohn said. “The Origin was the mature fruit of a prolonged process of scientific exploration and creativity that began toward the end of his Beagle voyage, which first kindled Darwin’s interest in evolution, and that continued to expand in range and deepen in conceptual rigor through numerous well-marked stages.”

The remainder of the manuscripts, which will be available in June 2015, will pick up in the year the Origin was published — 1859 — and will include the full record of Darwin’s massive experimental research program to substantiate the power of natural selection until his death in 1882. 

Work on the Darwin Manuscripts Project is supported by a grant from the National Endowment for the Humanities, Transcription and the National Science Foundation.