Interestingly we still have hunter/gatherer tribes around today, but only in the lush rain forests. I always feel like the progress (especially towards agriculture and thus permanent settlements) only happened with migration to colder climates. Which makes sense, as it sucks being a hunterer/gatherer when there's snow.

You can even experience it today: in the rain forests there's shit growing everywhere. Hungry? Walk around randomly for 5 minutes, there's bananas, or mango, or star fruit or whatever.

So the real question to me: why migrate in the first place?