Hongshan culture
This region was thought to have been desert for the past 1 million years. However, a 2015 study found that the region once featured rich aquatic resources and deep lakes and forests that existed from 12,000 years ago to 4,000 years ago. It was changed into desert by climate change which began approximately 4,200 years ago. Therefore, people of the Hongshan culture may have emigrated to the south approximately 4,000 years ago and later influenced Chinese culture.