I have started making maps of G2a subclades, as they represent quite distinct ancestry. The U1 subclade peaks in the Northwest Caucasus among the Adyghes (40%), Cherkassians and Kabardians. It hasn't been found in Neolithic Europe yet (to my knowledge) and its distribution indicates a possible connection with Maykop and an Indo-European propagation, probably tagging along with the R1b-U152. In Europe the L13 subclade of U1 in dominant and peaks in central Italy and especially in the Latium and northern Campania, which strongly suggests that it was present among ancient Italic tribes, including the Romans, as I have written for several years in the G2a page and the Genetic history of the Italians.