In 2009, I published The Tangled Bank: An Introduction. I intended it as a textbook for non-majors, as well as a guide to evolution for people looking for a thorough but non-technical account of how life has gotten to be the way it is. The project proved to be far more work than I had reckoned, but I was happy with how it turned out, especially thanks to the talented artists and designers I had the privilege to work with. The reception has been gratifying; the Quarterly Review of Biology, for example, called it “spectacularly successful.” A number of courses have adopted The Tangled Bank both in the United States and abroad.

It’s hard to believe that four years