Thesis #50 – Children and young adults with predominantly agricultural ancestry are well adapted to agricultural conditions of nutrition and activity, but children and young adults without agricultural ancestry are not adapted to such conditions.
Let us address with particular care the diet and the activity patterns of children, with respect to the relationship between such lifestyle questions, their health, and their evolutionary ancestry.
It is a straightforward corollary of the points that we have outlined to this point that children weaned from human breast milk should be fed and cared for in ways that depend on their ancestry. Those children whose ancestors were never subjected to agricultural conditions should not be fed novel agricultural foods, including but not necessarily limited to flour derived from grass seed and the milk of cows and other ungulates. There are probably other agricultural foods that they may be adapted to, such as many fruits, nuts, and a variety of “salad” vegetables, including lettuces and the like. Potatoes, yams, carrots, and other plant storage organs may also be harmless foods, particularly if cleaned and cooked so as to destroy any toxic compounds used by such storage organs to fend off nematodes, fungi, and other organisms that would otherwise consume the nutrients in such structures. However, there is still a significant amount of anthropological research that is needed to determine which dietary components can be safely consumed by children who come from populations that have never adapted to agricultural conditions. A further point is that such children probably have fewer adaptations to recurrent viral infections, due to the lower incidence of viral pandemics among hunter-gatherer populations. Thus they may not fare as well in large schools, due to recurrent infection.
Children with predominantly agricultural ancestry have been rigorously selected for dietary and other adaptations to agricultural conditions, including a higher level of exposure to viral infections. These children can eat pre-industrial agricultural foods, such as bread, rice, or cow milk, to the extent that their evolutionary ancestors consumed such diets. These children will also fare better in large schools, and under urbanized conditions generally, due to greater resistance to contagious diseases.
The term “children” here would refer to individuals who are at ages during which the forces of natural selection remain quite high, which would certainly continue into the early twenties, with respect to years of age. But in this sense, individuals over the age of thirty years are no longer children who have benefited fully from antecedent natural selection over hundreds of generations.
A further issue that arises is how to treat children with mixed ancestry, in terms of the proportion of their ancestors who have been subjected to selection for adaptation to agricultural conditions. In such cases, it is probably better to err on the side of treating such children more in the fashion appropriate to those from non-agricultural lineages. They may retain some reasonable level of adaptation to non-agricultural diets and lifestyles, together with an admixture of attributes that will enable them to endure some features of the agricultural lifestyle. Finally, it should be noted that those whose ancestry is from the margins of agricultural civilizations, like the northern Scottish or the Mongolian nomads, may have significantly less adaptation to agricultural conditions than those from the long-established centers of such civilizations, such as Egyptians or Han Chinese.