Online notes offer insight into evolution of Darwin’s big idea

Darwin’s library amounted to 1,480 books, of which 730 contain a wealth of scrawled notes, providing an insight into his thought processes and struggles as he wrote On The Origin Of Species.

For example, his friend Charles Lyell wrote in his famous Principles Of Geology that there were definite limits to the variation of species. Darwin wrote alongside this: “If this were true adios theory.”

The majority of the collection in Cambridge University library and has now been digitised in an effort involving Cambridge, the Darwin Manuscripts Project at the American Museum of Natural History, the Natural History Museum and the Biodiversity Heritage Library.

University librarian Anne Jarvis said: “While there has been much focus on his manuscripts and correspondence, his library hasn’t always received the attention it deserves – for it is as he engaged with the ideas and theories of others that his own thinking evolved.”

Because Darwin’s evolutionary theory covered so many aspects of nature, reading served him as a primary source of evidence and ideas.