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In Henry’s view, the adoption of a more settled existence in areas with abundant food resources would have contributed to higher fertility levels among the sedentary foragers. A diet higher in wild cereals produces proportionally more body fat, leading to higher fertility among women. Cereals, which are easy to digest, would have supplemented and then replaced mother’s milk as the primary food for older infants. Since women are less fertile when they are breast-feeding, substituting cereals for mother’s milk would have resulted in closer spacing of births and the potential for a greater number of live births for each woman. A more sedentary existence may also have lowered infant mortality and perhaps increased longevity among the aged. These more vulnerable members of society could safely stay in a fixed village rather than be forced regularly to move great distances as part of a nomadic existence, with its greater risk of accidents and trauma.

托福真题（四科目）

https://docs.qq.com/doc/DSVFTUVNQVXNkalJS