The origin of the original Basques likely goes back to both, the Caucasus region as well as the Fertile Crescent.
Y-DNA markers among the original Proto-Basques from 5,000 ybp can be traced back to origin within the Caucasus regions and potentially the Eastern Mediterranean.
The female mtDNA lines go back to the Fertile Crescent region and later to newcomers connecting to Berbers and the Saami people of Lappland.
Around 3,000 to 4,000 ybp, the Proto-Basques were invaded by the Proto-Celts and their original y-DNA was almost completely replaced.
Oral tradition was interrupted and today’s Basques do not know their origin generally speaking. After the invasion, Basque women primarily raised their offspring with Proto-Celtic men preserving most of the original language.
The original Rh(D) negative frequency of more than 50% has since declined.