" wouldn't call them "stay at home," though, since it's pretty hard to ignore black african influences in the New World (the Olmecs and all). They got around, but their voyages were relatively recent."
This is probably some of the 250,000 Shang who 'took to the sea' at the collapse of the Shang Dynasty. My guess is that these are the elites and skilled from the Shang Dynasty...notice that one of the first things they did was build a pyramid.