rationalskepticism.org

stevebee92653 wrote:
on population
To repeat again: The starting population is fixed at two by me FOR SIMPLICITY's sake because that is the minimum number needed, one m AND f. Make it more if you like, but 2 is the minimum of course. A larger number than 2 makes things worse; the average time for doublings will INCREASE quickly from 4671 years. The total time span for the existence of homo sapiens is fixed and given as 200,000 years; fixed by evolution science and the fossil record. The population at the end of the 200,000 year fixed span is 8 billion, fixed because that is what it be will in 2025. So the AVERAGE length of time between doublings is also fixed. The ACTUAL time span for doublings is NOT fixed, and will be all over the place depending on conditions already listed, but the ACTUAL must AVERAGE out at 4671 years for there to be a population of 8 billion in 2025 from 2 people 200,000 years ago. Want to do MORE than 200,000 years ago?
Just for the fun of playing with numbers, let's pretend that there were 1,000 homo sapiens 200,000 years ago and see what that would look like. To reach a population of 8 billion in 2025, the population would have to double only twenty-three times in 200,000 years. Which means the population doubling would occur every 8,695 years, just about longer than the entire history of modern man. So year one, 198,000 BCE, there would be 1,000 people. 8,695 years later, there would be 2,000 people. 17, 390 years later the population would be 4,000. Astounding. Possible? I would seem not since human generations are about 20 years in length and average doubling since 1800 is 75 years. It would seem that any population that could be so easily wiped out to coincide with these figures would never have survived. But, of course we did.