Host Elise Hugh introduces a conversation between evolutionary biologist Richard Dawkins and linguist John McWhorter exploring parallels between biological evolution and the evolution of language. They compare extravagance in language to sexual selection in animals, discuss linguistic "junk" and genetic pseudogenes, examine dialects versus languages through a frog speciation analogy, contrast selection with drift in both domains, and debate how mixed and hybridized any "proto" ancestral language must have been.