Was their an evolutionary change that cause indians to lose the ability to have a sophisticated culture?

They were so behind the rest of the world this is really the only thing that would explain it. Even today with an advance culture all around them they can not get themselves off of the reservations. As for the theory that it is the difference in climates throughout the americas this has a huge hole in it because there are large parts of asia that are similar to this difference in climate. The only explanation is that they do not have and advanced enough intellect.