Stephen T Asma in Aeon:
Most of the people reading this article do not possess the skill to start a fire from scratch. And yet, many anthropologists think that the mastery of fire literally transformed our ancestors into human beings. They say it gave us cooking, protection and heat, and also reshaped our very anatomy. In Catching Fire (2009), the Harvard anthropologist Richard Wrangham argues that eating cooked food produced the efficient Homo erectus digestive tract, freeing up energy for brain growth.
Be this as it may, our ancestors lived for a long time without fire and we could presumably do it again, however unpleasant that sounds. In fact our ancestors did lose the knack of fire-starting, for generations. Control of fire first appears in South Africa as early as 1.5 million years ago. It crops up again in Israel and China around 700,000 years ago, but doesn’t appear in European populations until 300,000 years later. Why the dark interludes? Perhaps a tribe lost its master fire-starter to a predator before she had a chance to pass on the technique. Perhaps a whole population of fire adepts was wiped out in a single catastrophe. Either scenario could have blacked out whole millennia before the vital techniques were reinvented or re-encountered.
It appears, despite fire’s incredible value for survival, that natural selection has not given human brains any sort of prewired module for controlling it. Such skills belong instead to the realm of culture: not the high culture of libraries and works of art but an older, dumber process of transmission, working person-to-person and generation-to-generation, fragile enough to lose everything in a single tragic decade but sturdy enough to survive for millennia under the right conditions. And it isn’t the only vital skill to hang by so slender a thread.