Mastery Of Fire
The single most transformative event in the history of human bands, fundamentally altering both their biology and social structures was their mastery over fire. It shifted humans from just "another primate" to a unique "cooking animal" with a high energy lifestyle. Even at this stage they moved in bands foraging. The bands were a sort of consanguin relationship. Until at least 40000 years ago all humans lived in bands. In the course of our evolution we used ingenuity to out-source digestion, moving part of the process outside our bodies. This process is known as cooking and it served as a form of pre-digestion. It broke down complex starch and denatured protein making them significantly easier to digest. To early humans, it was a gain of 30 to 50 percent of energy from the same amount of food. Many plants like tubers and seeds that were toxic or indigestable when raw, became staple food source when cooked. Heat kills parasites and bacteria in raw meat...