One thing that I often hear in relation to human brain size is that the upper bound of our brain size is limited by the need for the brain to get through the pelvis during birth.
However, if this were the case, it seems that in equilibrium there should be a number of mutations which increase brain size (and by extension, intelligence), but these variants would be bounded in frequency by their negative effect on maternal survival (and which could provide low hanging fruit for intelligence selection in the modern world since survivability of difficult births is much higher with e.g. blood transfusions and c-sections).
However, as far as I can tell, there aren't genes which have this large effect, and IQ isn't a major predictor of difficult labour (though I haven't searched too much and I've no expertise in the area). Do you know what the error is here?
I find this important because it's part of the question of whether human intelligence rose continuously until we hit a critical point at which civilization exploded into life, or whether we were at some kind of long-term plateau and the core change was just a slow accumulation of physical, intellectual and social technologies until a positive feedback loop could take hold.
One thing that I often hear in relation to human brain size is that the upper bound of our brain size is limited by the need for the brain to get through the pelvis during birth.
However, if this were the case, it seems that in equilibrium there should be a number of mutations which increase brain size (and by extension, intelligence), but these variants would be bounded in frequency by their negative effect on maternal survival (and which could provide low hanging fruit for intelligence selection in the modern world since survivability of difficult births is much higher with e.g. blood transfusions and c-sections).
However, as far as I can tell, there aren't genes which have this large effect, and IQ isn't a major predictor of difficult labour (though I haven't searched too much and I've no expertise in the area). Do you know what the error is here?
I find this important because it's part of the question of whether human intelligence rose continuously until we hit a critical point at which civilization exploded into life, or whether we were at some kind of long-term plateau and the core change was just a slow accumulation of physical, intellectual and social technologies until a positive feedback loop could take hold.