This was kind of a no-brainer really: When humanity settled and began agriculture, it was bound to affect, if not doom, the environs in which it settled. That IS the entire premise behind human generated climate change, isn't it?
While the hunter-gatherer lifestyle sounds good, even appealing, that is actually only so much eco-romantic dreaminess. In reality, it is unsustainable for a mass of humans. If you can't kill or deter those who would intrude on your foraging area, then they compete - and you suffer at some point. You are also at the mercy of the elements and deprivations of Nature herself - lets face it, Nature can be a beeyatch when we least want her to.
I mean, having sabre toothed tigers trying to eat you while you gather berries is definitely NOT conducive to a meaningful foraging experience.
Ditto droughts and floods, disease and infection, etc... It is very rare for animals to die of old age in Nature.
It's kind of a bummer, really.
Inevitably, a foraging lifestyle allows us to rise little higher than the animals themselves - at each others throats for the few resources we don't deplete by our presence, while we try not to die from disease, starvation or being some other creatures dinner.
That whole, "Balance of Nature" jazz is great for fork tailed swifts or bristling thistles, but for humanity to actually get anywhere in it's development, we had to settle down and do something besides wait on the shoots to sprout.