Darwin employed the sixth edition to refine his own ideas and to answer his critics. The many illustrations, photographs, and footnotes that supplement Pechenik's text help clarify concepts and identify historical figures originally cited by Darwin.
Jan A. Pechenik is Professor of Marine Biology and Invertebrate Development at Tufts University. He is
the author of The Readable Darwin (2014), Biology of the Invertebrates (2014), A Short Guide to
Writing about Biology (2012), and more than 140 articles. From 1998 to 2001 and again from 2005 to 2008, he
served as Director of the Writing Across the Curriculum program at Tufts University.