Indians are originally from China as we have the same drinking gene besides same hair/eye color. I used to tell my date I'll not be responsible after the second drink.
Chinese walked across the Arctic from China to America - at one time it could be frozen to link the two continents. Some were lazy not to go further south and they became Eskimos. Some went further and they became Indians, and some even further and they became South Americans.
Why they had to escape? It could be they lost the war and ran for their life. Or, due to famine like the Irish migration. Or, they just lost their direction (I lost my way all the time so nothing to be ashamed of) - we had not invented the compass and astronomy yet.
Some ran to the west and became Tibetans, some to the East and became Koreans, and to the South and became Thais. When they had bigger boats like in Tang Dynasty or earlier, they became Japanese.
If you looked at the old temples in Korea, you probably can see the written language in Chinese. Modern Japanese language is partial Chinese. The ancient dresses of Japanese are very similar to Tang's.
From Time Magazine, a Chinese expert in ancient Chinese language could read the ancient language of a S. American country. That's why I said some became South Americans - they used to have longer legs.
I am just curious why the Eskimos and Indians did not have a language but that South Americans did. It could be that hunting did not require language skill but farming did (you need to write down when you sowed the seeds…).