Discovering Darwin

 In this episode we dive into Chapter 8 from Darwin's Descent of Man. James incorrectly attributed this chapter to the end of Volume I of the two volume set but it is actually the first chapter of Volume II, which makes more sense given its dramatic shift in focus and topic. Sarah tried to get us to differentiate between adaptive traits that come about from sexual selection with those that come about from natural selection.  Photo from https://rollingharbour.com/2017/02/14/bluehead-wrasse-private-life-laid-bare/We spent some time discussing the difference between sex-linked traits, like calico cat color,  and sexually selected traits like the giant antlers on the extinct Irish Elk.  James presented just a few hypothesis that have been proposed to explain female choice of traits and why those traits that females seem to prefer are often opposed by natural selection. It is hard to be a red male cardinal in the dead of winter. Sarah suggested interested listeners read The Evolution of Be