When did the earliest commercial activities appear?

In Xia Dynasty, early commerce appeared in Shang tribe. According to historical records, Wang Hai, the leader of Shang tribe, tamed cattle and invented ox cart in the middle of summer, which made productivity develop and goods surplus. Wang Hai led his people to barter with other tribes, so people from other tribes began to call them "businessmen" and their industry was also called "commerce". Wang Hai is honored as "the ancestor of Chinese businessmen".