erianaiel wrote:'doubling every 5 years'
That was in rebuttal to AMs assertion that the DJIA was linear between 1950 and 1960.
It was not, it doubled in 5 years, and doubled again in 5 years. That is 4 times growth in 10 years.
That is not linear.
Not for once do I believe that human population growth from the first human to now was a static figure.
But it had to be exponential, and not linear. Well, maybe for that first human if he or she only had one child live to reproductive age, and then died when his or her grandbaby were born.
That is the only time in human history that growth could have ever been theoretically linear.
I also personally believe that in pre history there were massive human die offs, probably so precipitous to push humans to the brink of extinction.
Note how all, or most of the prehistoric remains found are of species other than homo sapiens. They are almost always branches of hominids, not human, from a common ancestor. That suggests to me that humans, or our direct ancestors, were relatively smaller in number than their competitors.
And easily, today, the maternal death rate would be close to 33% per birth, without medical, midwifery, or nursing. While I don't necessarily think that prehistoric numbers were actually that high, because modern women who now give birth today, would have been selected out by maternal death prehistorically. The logically obvious, if she was never born because her mother died in childbirth, then should could never have died during childbirth. But it had to be high enough for us to invent medicine, midwifery, and nursing(and the other social or tribal traits to nurture mothers and children). Something that our competitors surely never invented.