Perhaps including the development of agriculture itself would help confirm some general ideas?

A preliminary look at the beginning of human agriculture seems to suggest that forest gardens were the first type of "grown food".

In fact, I would like to make what seems to me to be an unusual conjecture that as these gardens became more and more productive or intricate, the gardens depended more so on us than the other way around. An evolutionary cul-de-sac of sorts. Thus at some time, the effort needed for their upkeep began to -ironically - dominate the lives of otherwise nomadic hominids.

This "Garden of Eden" stage would would thus be a very convenient conceptual transition phase that may have coexisted with "savages" as it evolved to civilization.