Now that I am retiring perhaps I'll get around to making a bow.  I do not agree that bows and arrows came along about 500 AD in the new world.  I used to walk the corn fields as a lad picking up the occasional arrowhead and didn't realize until many years later that the different shapes were not only different tribal people but also from different time periods.  The oldest arrowhead that I found was about 4' deep in the bottom of a creek and according to the book was 6000 years old.  I am not a historian but logic tells me that there must have been some communication across the world.  Bow and Arrows are not the only thing that we notice is similar between "Old and New".  The land bridge to Asia might explain the bow, but what about the pyramids?We know that ancient civilizations had sea worthy craft.  I believe that there was more contact than we know of in recorded history.