“…Isolation by distance or natural selection due to a single factor cannot be invoked to explain the present results, chiefly because the principal-components method is not suitable to appreciate them [8,11,12], It has recently been demonstrated that some analogies exist between languages and genes [ 13] in Europe [14], including Italy [15], If we consider the classification of living dia lects spoken in central Italy [16], we can see that there is no positive association with our clusters since, for example, the dialect spoken in LI and PI belongs to a group different from that of TR, and PS is included in an area with a different dialect to that spoken in MC, AP and AN. The clusters obtained in the present study, instead, may reflect a distinction be tween a Tyrrhenian and an Adriatic area which is possible on the basis of both geogra phy, corresponding to the Apennine wa tershed, and 'dead' languages, i.e.…”