Innovations in hunter gatherer societies were spread out over millennia and were - with the exception of the use of fire - gradual improvements of simple tools that were already used by non-human primates for instance for cracking nuts and fishing for termites. Other species like humpback whales also developed innovative tools like the collective formation of "bubble nets" to trap prey.
The critical innovation that triggered the transition to modern civilizations was the organized and systematic production of food as opposed to hunting, gathering, and subsistence agriculture. Through this innovation the development of large cities and division of labor became possible. In terms of complex systems theory the amount of surplus food that could be produced by one farmer can be seen as a control parameter that at a critical value triggered a bifurcation with the emergence of new, self-organized order parameters in the form of city-states.