Around ten thousand years ago, the primitive ancestors entered the Neolithic Age as global temperatures were rising. The Neolithic Age can be roughly divided into four periods: early, middle, late, and the Copper-Stone transitional period. The Neolithic Age in China lasts for about seven to eight thousand years, and the archaeological sites of this era are scattered throughout the country. Along the middle reaches of the Yellow River is where the YangshaoYangshao Culture mainly distributed, with the PeiligangPeiligang Culture in the Pre-Yangshao Culture Phase being particularly noteworthy.