22 Jul 12
-Removed-maths doesn't account for disease, predators, wars famine.
"Some simple maths based on reproduction rates indicate that the worlds population could easily reach current levels within 4,500 years from an origin of 2 human beings."
no. i could go into how cheetahs are endangered from being to few (at a population of thousands). how disease, famine, predators would eventually off a population of 2+children, how birthing in unsanitary conditions with a non-doctor like adam would be the death of you.
but i won't (i just did).
23 Jul 12
-Removed-It is not just medical advances. It is also technological advances such as farming / animal husbandry and the various technologies required to allow cities. Even the wheel and draft animals are quite important for moving goods into cities.
Prior to the development of various sanitation technologies (even if it is as simple as carting off the excrement in buckets) most cities would grow to a certain size then suffer major epidemics.
I also suspect that you do not actually have human population statistics for most of the world and are actually incorrect about exponential growth. Certainly here in Africa, I do not believe the population grew significantly until European colonization brought greater peace and western medicine/sanitation.
23 Jul 12
-Removed-Some of the biggest killers in the last few centuries were plagues and wars (with the plagues winning I believe).
I think you discount medicine without realizing how old medicine is and how much an impact small discoveries can make.
Its interesting that the graph in your first link does not show major dips at the world wars or for the various plagues before that. The Black death for example killed 30-60% of Europe's population. The Spanish flu killed 3-6% of the worlds population.
Here in Africa diseases like Malaria have kept population growth down. My sister tells me that treated mosquito nets has made a big difference to infant mortality where she lives (in semi-rural Zambia).
When European settlers first came to Livingstone, they settled by the river and most died of malaria. For this reason, the town was moved away from the river (which presumably reduced the incidences of malaria). Such a simple thing as choosing town locations carefully may not seem like much and may not seem like 'medicine', but over time such planning based on observation can significantly improve life expectancy.
23 Jul 12
-Removed-Education systems (including the advents writing and printing) and increased life spans have made us much more capable creatures. Without an education system that starts teaching children at an early age, and with low life expectancy, there really isn't the time to learn and discover very much. Then you need some way to pass on those discoveries to those that come after you.