Must have gotten boring, so during a short interlude between periods of maximum glaciation, probably around 35,000 years ago a bunch of 'em took off WEST and went to Europe. They were eventually driven back by a return of maximum glaciation and moved South into three refugia, one of which included the Pyrenees and the French/Spanish border area. All the Northern, Western and Eastern Europeans descend from that group which fanned out to the North, West and East as the glaciers retreated.
Another group resided in a Southern European refugia. All the people along the North shore of the Mediterranean and much of the Middle East descend from those people. There was a third refugee for European people in the Middle East.
There was another group residing in Kazakhstan that went EAST during another short interglacial. They divided into two different East Asian groups about 20,000 years ago. Up until that they they resembled the folks who moved West to Europe. However, when this division took place somewhere in the Himalayan Plateau, one group developed an extra root on the teeth in the upper jaw.
The other group didn't.
However, neither group was, technically speaking, "European". Even their genes for "white skin" are different than the European distant relatives, and none of them digest milk well as adults.
AFTER the ice withdrew the oceans rose. Before that the folks with the extra root on their teeth had spread out from Southern Siberia into the mountains of Japan. When the ocean rose with the melting of the North American glaciers, the people on the continent became separated from those on what became known as the Japanese islands.
Similarly, the other East Asian group (which doesn't have the extra root on teeth) Spread East and South into what is now China. It is supposed that during this period more Southerly people living in SE Asia moved North into China and mixed with both populations. (So those Australoid characteristics you sometimes see in Japanese and Chinese are not your imagination).
Anyway, the guys with the extra tooth root are known as the Ainu if they lived on the Asian mainland and Jomon if they lived on the Japanese home islands.
That takes us to about 10,000 BC.
From that point on it was one thing after the other and the Chinese developed an indigenous civilization or two and that created other problems. For one, it drove the Ainu OUT of the Yangtze and and Hwang Ho river valleys. They moved NORTH into Siberian coastal areas.
Their Jomon cousins in Japan lived as hunter gatherers, with only a minor amount of agricultural development until the Yayoi invaded from China about 500 BC-. They then withdrew to the North and became known as the Emeshi people, and they also developed civilization, including the use of iron, to defend against the Yayoi. They appear to have held on nicely until the arrival of the Imperial Family and the people who became the Daimyo circa 6th Century AD.
These guys had developed in Siberia, moved to Nepal, conquered India by about 500 BC, then, about 200 AD they got kicked out and returned to their Siberian homeland (Yakutia).
The Imperial Family/Daimyo group readily conquered the civilized Yayoi but it took them about 700 more years to fully conquer the Jomon/Emeshi. That was finally accomplished by hiring Emeshi as Samurai and turning the Imperial Samurai against the wild Samurai in the North.
Once all the Emeshi were conquered they were relocated to Fukuoka where they were used to beat up on all the other Japanese to keep the Imperial Family/Daimyo in power. That worked out pretty well until Perry arrived!
Modern dentists report that 40% of modern Japanese have teeth with the extra root!
The Ainu on the Northeast Asian coastal region took the opportunity in about the 1600s, while the Japanese were up to their eyeballs in European troublemakers, to invade Hokaido and other Northern regions.
Of much more interest are the Imperial Family/Daimyo ~ the traditional Japanese leadership elite.
These people came from Siberia, not Korea, nor from Tibet, like all the other groups. If you look up Sakha or Yakut you will find them. There are thousands of articles about them on the net, may in Russian. The ESKIMO groups descend from an early BC offshoot of this crowd. Some American Indian groups may share considerable ancestry with them ~ see Dene.
Their big event was their move from Siberia to India, and then their return from India to Siberia. Along the way they fathered Buddha. That journey took doggone near 1,000 years ~ do don't get the idea that just 'cause you live in America that your descendants aren't going to return to Europe or Africa.
The modern Sakha/Yakut have numerous individuals who look Caucasion ~ which is 'cause they are. At the same time they have many individuals who look terribly East Asian, and again, that's 'cause they are.
This body of people share a single culture of animal herding but they really do have two races. Obviously there've been intermarriages over the many hundreds of years they've lived in the same place, but they are not totally mixed as yet.
The Japanese Imperial Families are remarkably light skinned BTW, but because of a totally different gene set than Europeans.
Aren't the Athapascan Indians thought to descend from a later group of immigrants to the Western Hemisphere than other American Indian groups? (Navajo is an Athapascan language.)