In this episode we finally confront Chapter 7 of Descent of Man,  entitled On the Races of Man. In this  chapter Darwin discusses the races of humans and outlines the scientific arguments of the time that questioned if humans are more than one species.  These arguments, of course, were based upon racist European views of the people from the lands their countries had colonized. Race is a social construct, not a biological identity, and we discussed why that is the case in this episode.   https://angelicadass.com/photography/humanae/ James Wagner's daughter participated in this awesome art project and she is included in the images above. At one point we noted that Darwin reintroduced the idea of a range of varieties of organisms that can interbreed along a geographical range, but the ends of the ranges were reproductively isolated. We introduced that idea, often called a ring species, in Season 1 Episode 3, which can be found here. Sarah loves her ectoparasites and their evolution and discussed Darwin's 30 year obsession with that issue. Here is a link to a wonderful series of articles about Descent of Man and that obsession. The opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY  Interlude music is We are Many, We are One a song from Up With People, a group of musicians who "stage song and dance performances promoting themes such as religion, racial equality, and positive thinking." Our own Mark Jackson played trumpet with Up With People before pursuing his career in psychology.