Peking Man Pocahontases
The American Indians are related to the Mongol thrill-killers. Originating in China like the Neanderthal did in Europe, they kept on getting pushed north by more evolved species until they lucked out in going on the lam to the Americas, where they continued their incessant intertribal genocide, necessitated by the fact that they were mentally incapable of developing the resources and had to loot and kill to avoid extinction.
These "Mongol" termed folks - no one knows their actual name or ethnicity did not originate from China (at least not to my knowledge or any confirmed findings) But had settled (originated?) in the Siberian and Alaskan areas. Fact is however that these "Proto-Siberian/Alaskans" were ALL nomadic and also did not change that behavior in regards to the Plains-Indians right into the 19-20th century. In contra to those Red-Indians having settlements (when the Europeans arrived) and engaging in agriculture in the Eastern Part of today's USA - and e.g. Aztec/Maya and the Pueblo folks in the New-Mexico vicinity.
Personally I am not much in support of this 20,000 thousand years ago - one time Bering-straits migration drive, but rather that several migration movements occurred via the Bering-strait and by those folks already roaming around in Alaska at that time. With the Plains-Indians maybe deriving from a last migration drive from around 4000B.C. stemming from Alaska/Canada.
The second migration route seems to be the Pacific Coastal Route Hypothesis - this could also explain the racial/ethnic differences of Siberian/Alaskan folks to e.g. Amazon Indians, or those in the South-American Andes.
To my knowledge the oldest archeological findings in regards to settlement and agriculture in China are those of the Hemudu culture in today's Northern Zhejiang province - about a three hours drive South-West of Shanghai. Earliest findings are estimated to be from 8000B.C. and more conclusive findings are from around 6000B.C. onward incl. the cultivation of rice. Findings from the same culture have also been found-excavated in prehistoric sites in the Philippines, Polynesia, Micronesia, and Indonesia, the sites that are about 1,000 years younger than the Hemudu sites. Among scholars, the Hemudu Culture is considered a key chapter of the prehistoric cultures in the western Pacific region.
The Majiabang culture - located 2h drive more north-West of Shanghai - more or less started of in the same timeframe.
A number of building remains from that period have been discovered so far, including wooden columns, the walls between the columns made of weaved reeds and painted with soil, roofs formed by reeds, bamboo and dry grasses, and the floor constructed with compact earth, mixed with gravels and shells. Most interestingly, there were even drainage ditches around some of the building sites found. It proves the traditional Chinese timber frame structure with tusk tenon joints had already been developed 7,000 years ago in the Majiabang cultural sphere.
It might therefore be very possible that those of the Hemudu culture, their forefathers - or their offspring's continued migrated from the Pacific towards South-America via boat. Explaining the ethnically obvious difference between Amazon Indians, those of the Andes regions, compared to those in Central and North America.
Anyway, there is still a lot of research and excavations to be done - in order to maybe find the conclusive evidence as to who and how North and South America was settled and by whom.