Genetics
In introduction to PCT Mario Alinei argues, following Cavalli Sforza, that the distribution of genetic markers largely corresponds to that of languages. He further contends that 80% of Europe's human genetic material dates back to the Paleolithic, and cites Bryan Sykes in claiming that only a fifth of European DNA can be traced back to neolithic incomers.
A 2009 study comparing mitochondrial DNA lineages of late hunter-gatherers, early farmers, and modern Europeans found large differences between the three groups. In particular, 82% of hunter-gatherers had maternal lineages that are rare in modern central Europeans.
The origin of paternal lineages remains difficult to prove because modern science is unable to extract Y-DNA haplogroups from Paleolithic samples. However, the recent analysis of Arredi, Poloni and Tyler-Smith (2007) suggests that R1b-M269, the most common western European haplogroup, may have entered Europe only in the Neolithic.
Read more about this topic: Paleolithic Continuity Theory