From Ask a Korean
Here is ask’in another Korean who’s actually studied the anthropology.
There are certain types of East Asian physical types. Northern Asian, Southern Asian and islander aborigines.
Koreans are essentially of the Northern Asian type, which migrated from Siberia in the last ice age. Northern Asians are characterized by high cheek bones, small flat noses and wide eyes with an epicanthal fold. Northern Asians evolved from areas where it was very cold, and there was a high wind chill factor. High cheek bones and a flatter face helps the heat distribute better in and around the head. wider set eyes helped keep wind out as well.
The Chinese are a blend of Northern and Southern Asians. South Asians have rounder faces, slightly larger eyes and darker skin. It is well known amoung Chinese themselves that people from the North and the South look noticeably different.
The Japanese are a blend of Northern, Southern and islander aborigine (in approximately that order), with the Northern influence being more prominent on average.
No wonders I do like the cold… heh.