Humans had to use collective learning to come up with new adaptive strategies as they migrated in search of food, moving into environments they had never experienced before. They also altered landscapes and hunted many species to extinction.
(This is the typical map view that we are used to seeing.)
(This view may help you on the Quest!)
Follow the migration of humans across the planet and throughout history!
Though we may have changed how we name time, the distance from us remains unchanged...
except for each passing year making history farther and farther away.
Through the process of migration, humanity conquered the Earth! Or, at least moved from Africa into the rest of the Earth.
As human beings spread out across the world and populations grew, humanity reached a critical mass of innovators, and collective learning took off! All these innovations were great for lots of human endeavors, but none was quite as grand as agriculture.