On the Origin of Species: The Preservation of Favoured Traces

Darwin's On the Origin of Species is the book that introduced the theory of evolution by natural selection and launched the field of evolutionary biology. But the text itself evolved, too, from the first edition published in 1859 to the sixth in 1872. Chapters were shortened and lengthened, words added and deleted—though, more were put in than taken out, as the final edition measures in at 40,000 words longer than the original.

Ben Fry, director of Seed Visualization and the Phyllotaxis design laboratory in Cambridge, Massachusetts, has tracked these changes and put it all together in a fascinating look at the Origin's evolution. He writes about the project,

The idea that we can actually see change over time in a person's thinking is fascinating. Darwin scholars are of course familiar with this story, but here we can view it directly, both on a macro-level as it animates, or word-by-word as we examine pieces of the text more closely.

Color-coded by edition, On the Origin of Species: The Preservation of Favoured Traces is up now on Ben's website. Scroll over the screen while the visualization changes to see individual lines of text, and read more about the project here.