Who were the Indo-Europeans? Were they all-conquering heroes? Aggressive patriarchal Kurgan horsemen, sweeping aside the peaceful civilizations of Old Europe? Weed-smoking drug dealers rolling across Eurasia in a cannabis-induced haze? Or slow-moving but inexorable farmers from Anatolia?These are just some of the many possibilities discussed in the scholarly literature. But in 2012, a New York Times article announced that the problem had been solved, by a team of innovative biologists applying computational tools to language change. In an article published in Science, they claimed to have found decisive support for the Anatolian hypothesis.In their book, The Indo-European Controversy: Facts and Fallacies in Historical Linguistics (Cambridge University Press, 2015), Asya Pereltsvaig and Martin Lewis make the case that this conclusion is premature, and based on unwarranted assumptions. In this interview, Asya and Martin talk to me about the history of the Indo-European homeland question, the problems they see in the Science article, and the form that a good theory of Indo-European origins needs to take.