In a more severe environment, the primitive ancestors of the human species with a less specialized brain would be more flexible in a changing environment.
Many crucial adaptations originated on the African Savanna due to the high levels of environmental pressure, evolutionary changes related to this ecosystem include bipedal locomotion.
Upright walking is scientifically linked to a shift in the brain case’s structure, this allowed the brain to have more room to grow and develop.
For the human brain to reach its current genetic state, millions of years of evolution have been compiled. Over time, natural selection caused the most fit organisms to dominate the population. Yet, in a constantly changing environment, animal adaptation is perpetual.