Basically all you need is a single person traveling to a new area and reproducing and people travelled a lot more than our provincial thinking assumes. Just thi

Basically all you need is a single person traveling to a new area and reproducing and people travelled a lot more than our provincial thinking assumes. Just think of Assyria taking entire civilizations and transplanting them in new areas. The mongols, German hordes, Vikings, etc. raping and pillaging around the world. Polynesian sailors having contact with both SE Asia and South America. All the European colonization. Etc.