Y haplogroups and language families

The genetic variability of Y chromosome in human is well known and shows striking geographical patterns. These patterns are often in very good agreement with the distribution of language families: for instance in America  two main haplogroups are present, corresponding well to the two main families, na-dene and amerindians (although it must be stressed that there is not universal consensus on this calssification); haplogroup A corrseponds closely to the distrbution of Khoisan languages and so on.

However, the situation in Europe is more confused. There is an haplotype R which matches closely the distribution of Indo-European languages (Europe and northern India), but there are many incongruencies, the Basks, for instance, who are linguistically completely isolated, are genetically very similar to the Celt speaking Irish. The main problema are with dating. The R haplogroups, for instance, is dated at about 20.000 years ago, whereas Indoeuropean languages are documented from about 5000 years ago (Hittite) and are probably not older than 6000 years BP.