Recent genetic data suggests that ancient Italic tribes, including the Romans, were closely related to the Alpine Celts who founded the Hallstatt and La Tène cultures. In other words, the Romans conquest of Gaul was more like the final part of the unification process of the Italo-Celtic tribes.

Genetic evidence

The S28/U152 SNP was discovered as a subclade of haplogroup R1b about 2 years ago and tests have become more widespread over the last year. The original trend seem to point at a Celtic origin for this haplogroup, with a possible origin in the Black Forest or Switzerland.