Преобладание монголоидного элемента в степях Казахстана и Средней Азии началось уже со второго тысячелетия новой эры.Ранее зоной контактов были Сибирь, Алтай, запад Китая.
И R1a1a предки Хиюнгну тоже изначально Европеоиды и что?, точнее Северные Кавказоиды без южной Кавказиоидной примеси.
А северные Европейцы севодня например это микс Северных и Южных Кавказоидов(Skoglund et al.).
"Northern Caucasoids" are people like PWC or early Bronze Age Altai (the people at the top of the plot).
"Northern Europeans" were formed by admixture of northern Caucasoids with southern Caucasoids (see Skoglund et al.). Coon had the basic idea right when he postulated that: (i) Upper Paleolithic "survivals" were highest in northern Europe, but (ii) Europeans were formed by what he called "Mediterraneans" interacting with UP survivors.
The Scythians studied here do not appear to be northern Caucasoids. Of the unmixed Europeans they appear closest to Bulgarians and Albanians (p. 200) who are not even northern Europeans, let alone northern Caucasoids. And, they most certainly appear more "southern" than the earlier groups, consistent with other Iron Age groups.