I agree, I am not saying the lifestyle was overall great or anything.  Just that it was better than you might think.<p>Though as to disease it&#x27;s not just population density.  Domesticated animals mostly birds, pigs, and cattle for example created a larger pool to spread disease.  Though diseases will spread from primates to humans with minimal contact.<p>PS: You could also have separate populations with minimal contact and have fewer diseases evolve.  So, we could have high population density as long as people did not travel or keep animals.