In this program, John McWhorter, author of The Power of Babel: A Natural History of Language; Lyle Campbell, of the University of Utah; Brian Joseph, of The Ohio State University; and population geneticist Luigi Luca Cavalli-Sforza examine factors that contributed to the diversification and spread of languages, including early migration, the introduction of agriculture, and genes. Language transfer from mother to child and from one population to the next is also investigated, along with the concept of dialects and commonalities among the worlds more than 6,000 languages.