Looked at from the point of view of other organisms, humankind resembles an acute epidemic disease, whose occasional lapses into less virulent forms … - William Hardy McNeill

Categories of understanding along with everything else alter as societies change.

By the sixth century A.D., ...a distinctively Chinese Buddhist art had arisen, in which figures with Chinese dress and Chinese faces nonetheless continued to conform to Indian conventions of gesture and ornament.

Details of early domestications remain unclear. One must assume a process of mutual accommodation between humanity and various domesticable species. This involved rapid and sometimes far-reaching change in the biological character of domesticated plants and animals as a result of both accidental and deliberate selection for particular traits. Conversely, one can assume that a radical, if rarely deliberate, selection among human beings occurred as well. Individuals who refused to submit to laborious routines of farming, for instance, must often have failed to survive, and those who could not or would not save seed for next year's planting, and instead ate all they had, were quickly eliminated from communities that become dependent upon annual crops.