Neves suggests that the first Americans are not Australian but rather are descended from an ancestal population.
" There is no necessity of invoking the occurrence of trans-oceanic migrations to explain the pattern of biological affinities we have been finding for the first Americans. The best way of reconciling the pattern of morphological similarities found in this work with common knowledge about human evolution in East Asia is to assume that both the first Australians and the first Americans shared a common ancestral population in mainland Asia. This ancestral population could well be represented by hominids similar to the Zhoukoudian Upper Cave people (Kamminga and Wright, 1988; Wright, 1995; Neves and Pucciarelli, 1998) and its ultimate origin can be traced back to Africa. "
Zhoukoudian Cave is in north China.
In my opinion, a lot of these folks were all disrupted from their homeland by the Ice Age melt. Some came from Sundaland.