There's no proof that humans have hit any such limits. But that's not how genes and evolution work. We got intelligent enough to adapt to the environment and co

There's no proof that humans have hit any such limits. But that's not how genes and evolution work. We got intelligent enough to adapt to the environment and conditions that were thrown at us to survive the ice age and through the many inter-tribal wars that have been fought since. But once a species hits a plateau in selection pressure there is little improvement, except via sexual competition.