That's not necessarily true. Divergent evolution of ideas means that there could be some truly primitive ideas that's still useful to us today simply because we

That's not necessarily true. Divergent evolution of ideas means that there could be some truly primitive ideas that's still useful to us today simply because we never went down that particular tree in our development. It's hard for us to imagine, but that's the point. I mean just look at how many of our everyday gadgets hasn't changed much in the last 100 years. Zippers for instance:)