Chinese are descendants of Abraham and Natives come from Babel

Chinese people are descendants of Abraham. When Sarah passed away, Abraham married Keturah but he had other concubines besides that. Any offspring he had from these concubines were sent towards the East (China). 

Genesis 6:25

But Abraham gave gifts to the sons of the concubines which Abraham had; and while he was still living he sent them eastward, away from Isaac his son, to the country of the east.

In the past, scholars believed that China was the land of Sinim mentioned in Isaiah 49:12:

Surely these shall come from afar;
Look! Those from the north and the west,
And these from the land of Sinim.”

However, this theory was proven wrong. The land of Sinim was indeed the eastern province of Egypt, land of Syene, southern Egypt, near Aswan.

Matthew 2:1

Now after Jesus was born in Bethlehem of Judea in the days of Herod the king, behold, wise men from the East came to Jerusalem,

Between 6 B.C. and 4 B.C., not many countries had the technology and advancement in astrology or astronomy. This leaves us with China.

Finally, Chinese history contains historical evidence that they indeed worshipped the God of Heaven just as Abraham did. They worshipped an ancient God, by the name of 'Shang Ti', which translates to 'Lord-on-high', creator of all, and supreme God. Previous Shang Dynasty emperors worship this God, offering sacrifices of livestock on a stone altar.

Even Chinese characters contain historical evidence, such as the word, 'boat' which shows rain and 8 people. As for Chinese characters, I strongly suggest to read more about them here: https://creation.com/images/pdfs/tj/tjv13n1chinese_lamb.pdf

Aboriginals and other indigenous natives came from the Tower of Babel. First nations people are the first who have arrived on a particular nation, and thus, given the title 'First Nations' people. Whether they are red Indians, Eskimo or aboriginals, advancement of their civilization are usually primitive, suggesting they first stepped foot in that country thousands of years ago. So how far back do we go and where did they originate from?

Genesis 11:8-9

So the Lord scattered them abroad from there over the face of all the earth, and they ceased building the city. 9 Therefore its name is called Babel, because there the Lord confused the language of all the earth; and from there the Lord scattered them abroad over the face of all the earth.

This is why we see similar designs of buildings and sculpture shaped in the same way but in very different parts of the world -- because the human race was scattered around the earth at the same point of time in history. I hope this answers some questions.