I believe, ( and that's just my thoughts), that continued learning and invention of better and more efficient ways, stopped when free movement ended. With all property now being held by the Federal, state and Borough governments, it's impossible to live and survive like the people could back then. Add to that equation, the personal property of new residents of this land and the restrictions are like a choke hold. The people are still here and are just as wise but are so very limited in what is allowed. That's the difference of Native life and the European ideology of land ownership. It can't revert to those days but I think that was the undoing of a successful culture. It happens every where in the world.