linguistic archeology     In the paper Mapping the Origins and Expansion of the Indo-European Language Family [Science 337, 957 (2012)], a team led by Quentin Atkinson, of the University of Auckland, in New Zealand, researched the homeland of the Indo-European language family by adapting ‘phylogeographic’ methods initially developed by epidemiologists to trace the origins of virus outbreaks. Instead of comparing viruses, they compared languages and instead of DNA, they look for shared cognates – words that have a common origin, such as "mother," "mutter" and "madre" – across 83 modern languages as well as 20 ancient ones for which records are available. They used the cognates to infer a family tree of the languages and, together with information about the location of each language, they trace back through time to infer the location at the root of the tree – the origin of Indo-European.

language expansion in time and space

Figure showing the expansion of the language family across Europe through time: Estimates for the location of ancestral nodes on the tree (representing ancestral languages) are plotted as opaque points with a color that indicates their corresponding age. Older nodes are shown on the foreground to better show the expansion. (NB: – This figure needs to be interpreted with the caveat that we can only represent the geographic extent corresponding to language divergence events, and only between those languages that are in our sample. The rapid expansion of a single language and nodes associated with branches not represented in our sample will not be reflected in this figure. For example, the lack of Continental Celtic variants in our sample means we miss the Celtic incursion into Iberia and instead infer a later arrival into the Iberian peninsular associated with the break-up of the Romance languages (and not the initial rapid expansion of Latin). The timing represented here therefore offers a minimum age for expansion into a given area.)