So there were many hominid migrations before homo sapiens, and the subsequent sapiens migration killed and mixed with the other ones, gaining part of their physical characteristics. Europeans mixed with neanderthals,. Chinese mixed with pekinensis and juluensis , indonesians with floresiensis, and the only "pure" humans are subsaharan africans

>>17756771 (OP)
No. Human Genome has been sequenced and the only two hominid species we are confirmed to be admixed with were Neanderthals (peaks at like 4% percent in East Asians iirc) and Denisovans who likewise peak at around 4% in Papua.
Homo florisiensis, Pekinensis, and Juluensis went extinct before they came into contact with modern humans.
As for amdixture in Africans we are still on the fence about that.

>>17756804
This is surface level tier. Everything OP said is correct except the last bit because blacks mixed with four hominid populations.