AFAIK, size is ancestral north eurasian and european ice age contribution. Human body form for strength is northern european, and Human body form for symmetry is slavic and northern indian. The central asian expansion divided that symmetric population in half east west, just as the european population was divided north south and east west by anatolian farmer and then steppe admixture events. Europeans during the ice age were compressed along the border of the ice most southernly in west europe and most northernly in north central asia (today’s russia), followed by a counter-clockwise western rotation of asians causing both the minor asian admixture events we see in finnic people and the eastward admixture of ancestral north eurasians and east asians into siberian then amerindians, and the amerindian (siberian american) expansion.
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