When those journeys were across water, they could have been facilitated by fire, in part because, under many circumstances, burning out the hulls of trees to make them into canoes is a faster route to having a functional boat than is carving. Being able to take fire with us also opened up territory that was colder than anything we could have survived without it, allowing for exploration of the entire globe. And the control of fire led to the invention of cooking, which saved both time and energy, and ultimately led to the proliferation of cuisines and methods that we have today.
