A new paper in Science claims to have ascertained the locus of origin of the Indo-Europeans, Mapping the Origins and Expansion of the Indo-European Language Family. These are bold claims, and naturally have triggered a firestorm. No surprise, the same happened with these researchers when they published the result in 2003 that Proto-Indo-European flourished ~9,000 years ago, in alignment with an “Anatolian hypothesis,” as opposed to a “Steppe/Kurgan hypothesis.” The original paper in 2003 utilized phylogenetic methods which are common within biology, and applied them to linguistics. This second paper now incorporates spatial information into their model, to generate an explicit locus of origination, in addition to the dates for the bifurcations of the node.
In relation to results I think that the figure to the left is the most important, because it gives us their inferred dates of separation between various Indo-European language families. Observe that Italic and Celtic did not diverge in prehistory, but in history (i.e., the Sumerians and Egyptians were flourishing at the time). Additionally, the diversification pattern is not a simple “rake,” there is internal structure. They may date the origin of Indo-European languages …