"an average lifespan of 30 to 35 years", You are making up figures and then claiming "Everything I say above is historically accurate" - truly disingenuous of you. If you look at the life of many natives now, it is arguably much worse than the life they would have had without "wheels" and "mathematics". And no, the lifespan of hunter-gatherers was not "30 - 35", that is a common fallacy/propaganda to make modern people feel good about themselves. According to some studies, at least 30% of hunter gatherers lived past an average modal lifespan of 72. The great difference is in child mortality today due to the advent of antibiotics.