There was an interesting show on the National Geographic channel that purported to trace humanity's ancestry through the Y chromosome to a common ancestor - a "scientific Adam." That every male might have the same minor mutation apparently indicates that every last dude on the planet could be traced back to one guy. While I'm not totally convinced, it was definitely intrigueing; tangentially, I'm of the opinion that the Garden of Eden story is an allegory of humanity gaining sentience (once sentience was gained, then looking back on a time where there was no worry over mortality and all our other foibles might lead one to consider it paradise). In the show it was suggested that tool use began at almost the same time that the scientific Adam was dated to have existed, and furthermore that language might have similarly arisen concurrently. If it's true, it almost makes me wonder whether some oral history was passed down that told of a common ancestor or leader that generated those old creation yarns.