The Multivariate Basis of Human Brain Evolution: The Prerequisites of Fire Control and Cooking

This study investigates the evolutionary origins of the human brain, focusing on the trend of increasing size in hominins, while also addressing exceptions such as Homo naledi, Homo floresiensis, and the recent reduction observed in Homo sapiens. It examines hypotheses related to brain enlargement, challenging the Social Brain and Ecological Hypotheses by suggesting that the increase in brain size was not an inevitable response to social complexity or ecological pressures. While the Cooking Hypothesis is considered, it is not identified as the primary driver of brain expansion. Instead, fire control and cooking are proposed as prerequisites for sustaining brain size increases by meeting the energetic demands of larger brains. Additionally, we examine mutations that influenced brain size and complexity and contributed to the genetic variability that was pivotal to brain evolution, particularly in Africa during its final phase.