I think this might be the reason for the strength disparity. Tasks that require strong people tend to be more dangerous but a sensible tribe leader would send the strongest to do these tasks whether they are male or female. A tribe where the strength balance leans female will grow slower than a tribe where there is equal distribution which will grow slower than one with male balance. This selection effect would cause evolution in that direction.
Male/female size differences would have evolved prior to humans as a recognizable species evolving - and the fossil record of pre-humans supports this.
Humans have never self-selected for physical fitness with any regularity, throughout the historical record. We primarily mate for social reasons.
I think this might be the reason for the strength disparity. Tasks that require strong people tend to be more dangerous but a sensible tribe leader would send the strongest to do these tasks whether they are male or female. A tribe where the strength balance leans female will grow slower than a tribe where there is equal distribution which will grow slower than one with male balance. This selection effect would cause evolution in that direction.
Male/female size differences would have evolved prior to humans as a recognizable species evolving - and the fossil record of pre-humans supports this.
Humans have never self-selected for physical fitness with any regularity, throughout the historical record. We primarily mate for social reasons.