Via the Nature blog The Great Beyond: a “rather wonderful graphic” from Ben Fry that tracks the changes across all six editions of The Origin of Species, as Darwin refined and developed his idea in print from 1859 to 1872.

Fry’s visualization of Darwin’s edits is called “On the Origin of Species: The Preservation of Favoured Traces,” and it’s pretty mesmerizing — you watch as color-coded text is added and dropped from edition to edition, and you can mouse over to see each exact passage as it gets crisper and detail is added. The Great Beyond quotes Fry:

“The idea that we can actually see change over time in a person’s thinking is fascinating,” says Fry. “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.”

Watch the evolution of the idea of evolution >>