It's misleading to some degree. There is an obvious East-West cline as there is a North-South cline...
One needs to represent this for what it is..."Western" pure and simple until such time there are Northern markers...which unduobtedly there are but for reasons unknown to me Dienekes is not using them??
It is not originally "Western". This admixture is found as far east as Mongolia (5%) and as far south as India (12% in the Vaishya Hindus). In my opinion, this admixtures comprise one Proto-Indo-European element from Russia, which is why the so-called 'Western European' admixture exceeds 30% in Russians, and reaches almost 40% in Ukrainians. It's just that Slavic people inherited a greater percentage of 'East European' from the Baltic region, but the origins of most of the "Western European" admixture might be in the North Caucasus, South Russia and Ukraine.