Approx. 10,000 B.C.: The beginning of the "Neolithic" period, or "Agricultural Revolution," i.e., farming and animal husbandry. The transition to agriculture was made necessary by gradually increasing population pressures due to the success of Homo sapiens' prior hunting and gathering way of life. (Hunting and gathering can support perhaps one person per square 10 miles; Neolithic agriculture 100 times or more that many.[61]) Also, at about the time population pressures were increasing, the last Ice Age ended, and many species of large game became extinct (probably due to a combination of both intensive hunting and disappearance of their habitats when the Ice Age ended).[62] Wild grasses and cereals began flourishing,* making them prime candidates for the staple foods to be domesticated, given our previous familiarity with them.[63] By 9,000 B.C. sheep and goats were being domesticated in the Near East, and cattle and pigs shortly after, while wheat, barley, and legumes were being cultivated somewhat before 7,000 B.C., as were fruits and nuts, while meat consumption fell enormously.[64] By 5,000 B.C. agriculture had spread to all inhabited continents except Australia.[65] During the time since the beginning of the Neolithic, the ratio of plant-to-animal foods in the diet has sharply increased from an average of probably 65%/35%* during Paleolithic times[66] to as high as 90%/10% since the advent of agriculture.[67]
Remains of fossil humans indicate decrease in health status after the Neolithic. In most respects, the changes in diet from hunter-gatherer times to agricultural times have been almost all detrimental, although there is some evidence we'll discuss later indicating that at least some genetic adaptation to the Neolithic has begun taking place in the approximately 10,000 years since it began. With the much heavier reliance on starchy foods that became the staples of the diet, tooth decay, malnutrition, and rates of infectious disease increased dramatically over Paleolithic times, further exacerbated by crowding leading to even higher rates of communicable infections.
Skeletal remains show that height decreased by four inches* from the Late Paleolithic to the early Neolithic, brought about by poorer nutrition, and perhaps also by increased infectious disease causing growth stress, and possibly by some inbreeding in communities that were isolated. Signs of osteoporosis and anemia, which was almost non-existent in pre-Neolithic times, have been frequently noted in skeletal pathologies observed in the Neolithic peoples of the Middle East. It is known that certain kinds of osteoporosis which have been found in these skeletal remains are caused by anemia, and although the causes have not yet been determined exactly, the primary suspect is reduced levels of iron thought to have been caused by the stress of infectious disease rather than dietary deficiency, although the latter remains a possibility.[68]
Remains of fossil humans indicate decrease in health status after the Neolithic. In most respects, the changes in diet from hunter-gatherer times to agricultural times have been almost all detrimental, although there is some evidence we'll discuss later indicating that at least some genetic adaptation to the Neolithic has begun taking place in the approximately 10,000 years since it began. With the much heavier reliance on starchy foods that became the staples of the diet, tooth decay, malnutrition, and rates of infectious disease increased dramatically over Paleolithic times, further exacerbated by crowding leading to even higher rates of communicable infections.
Skeletal remains show that height decreased by four inches* from the Late Paleolithic to the early Neolithic, brought about by poorer nutrition, and perhaps also by increased infectious disease causing growth stress, and possibly by some inbreeding in communities that were isolated. Signs of osteoporosis and anemia, which was almost non-existent in pre-Neolithic times, have been frequently noted in skeletal pathologies observed in the Neolithic peoples of the Middle East. It is known that certain kinds of osteoporosis which have been found in these skeletal remains are caused by anemia, and although the causes have not yet been determined exactly, the primary suspect is reduced levels of iron thought to have been caused by the stress of infectious disease rather than dietary deficiency, although the latter remains a possibility.[68]
選擇“Disable on www.wenxuecity.com”
選擇“don't run on pages on this domain”
