> Couldn't evolution have settled on bigger brains if they are an advantage? Biological brains are limited by other factors. Human brain size in particular is

> Couldn't evolution have settled on bigger brains if they are an advantage? Biological brains are limited by other factors. Human brain size in particular is limited by factors like needing to fit through a human birth canal without wrecking an upright walking gate ([0]) and being able to be powered using a hunter-gather diet. [0] - loosing the upright walking/running gate would have limited certain ecological options (like persistence hunting). Instead, human gestation is shorter than it should be given our body size when you compare it to other mammals.