>>13911084Mainly through Australasian and Polynesia. Remote sites in South America were settled initially by a group who were both basal to Australoids and Asians, then later on it was settled by Polynesians.
North America was settled by a group who was basal to both East Asians and Europeans from central siberia, then later on by Ainu type people and north-east siberia, then even later on by Chinese people. Of course over centuries these two groups bled together in contact by central America that it became impossible to tell these origins, save for in some extreme isolates such as the Karitiana or Surui. Generally across America there is no exact way to determine relatedness, such as the Inca who became modern Peruvians are more related to the Aztecs (who became modern south Mexicans) genetically than the more Eastern jungle dwelling groups.
Also note that America in general has experienced and EXTREME founder effect. Imagine if you took about a thousand Eurasians and blew their population up to 10 million while subjecting them to new evolution. Native Americans carry the lowest amount of genetic diversity of any group in the world.
