Today, a fast moving, sidestepping, gene-swapping free-for-all that would’ve made Darwin’s head spin. David Quammen tells us about a shocking way that life can evolve - infective heredity. To figure it all out we go back to the earliest versions of life, and we revisit an earlier version of Radiolab. After reckoning with a scientific icon, we find ourselves in a tangle of genes that sheds new light on peppered moths, drug-resistant bugs, and a key moment in the evolution of life when mammals went a little viral. Check out David Quammen's book The Tangled Tree: A Radical New History of Life This episode was produced by Soren Wheeler. Support Radiolab today at Radiolab.org/donate.