What makes the last 11.000 years so different from all the millenia before? Why did the humans in America, in the Middle east, in Egypt, in China all develop agriculture within a relatively short frame of time, when no human had developed agriculture in the previous 100.000 or 200.000 years?
Related questions would be why writing, astronomics, math, or cities were all independently developed several times during that time frame and not in the much longer time humans had existed before. However, I guess that all of these could stem from having developed agriculture, therefore that one is of most interest to me.
(1) Ice Age, and (2) Evolution of Human Food gathering skills.
Before and during the last Ice Age, human beings were forced to compete with very large animals for very scarce food.
Hunting was the primary method of food gathering. Additionally, scarcity of food means that human populations were spread out over massive areas, migrated, mobile, to increase the chances of obtaining food and survival. (staying in 1 location usually means food would be hunted to extinction in the area, and then starvation).
When the Ice Age ended, local food growth increased. Plant life became plenty, so did animal life. Around the same time, human tribes around the world began to settle permanently in specific areas (around rivers), where food was plenty.
As population grew, hunting was no longer sufficient to meet the demand of large populations.
Seed gathering, used to be a way to supplement food sources, then turned into agriculture methods, where human tribes began to grow food from seeds, as the main source of food for large human settlements.