<HTML>Well, one answer is that climate change reduced the available amounts of wild plants. There was probably a time when cultivation was introduced as a supplement to the normal hunting-gathering routine (perhaps accidental discovery that dropped seeds grow new plants). Over time, as new the cultivated plants were artificially selected for the best traits, they perhaps became more desirable than their wild counterparts. Coupled with population pressures and changes in climate that favored horticulture, cultivation became an established supplement to the diet, eventually become the dominant form as people began to value the predictable value of the cultivation over the fast-changing wild populations.
So in short, you are right. It is simplistic to say more people and different climate made for farming, but we are talking about long periods of time where cultigens went from minor percentages of the population to total dominance. In prehistoric America, for example, the first cultivated corn (maize) made up only one percent of the diet in AD 100, but after AD 1000 (the Medieval Warm period) it ballooned to 70 percent of the diet.
In fact, the first cultivated plant in the New World was the bottle gord, which cannot be eaten. It was apparently grown as a container, implying agriculture began for reasons other than food production and became centered on food only AFTER the population grew too large for the natural environment to feed. Cotton, another inedible crop, was also among the oldest cultigens. It was apparently grown for religious reasons.
Jason</HTML>
