Page 190 - Encyclopedia Of World History

540 berkshire encyclopedia of world history

epidemiology of infectious agents, reservoirs, and vectors. years, equaling or exceeding that of many European pop-
The trends can also be observed through the experience ulations of recent history.
of living groups with various lifestyles. Each kind of Foragers in small and relatively isolated groups con-
analysis is flawed, but taken together they provide a nected only by the speed of walking probably suffered
coherent picture of past health and nutrition. two major categories of disease:The first would have been
relatively mild chronic diseases, such as yaws or herpes,
Small Foraging Groups long-lived in individuals and passed directly from person
The earliest and smallest human groups appeared in to person, which can survive in small groups.The second
modern human form about 100,000 years ago, foraging category includes diseases that are zoonotic—that is,
for fresh wild resources in small mobile groups. They they are transmitted primarily among other animals;
accounted for almost all human populations until about while they do occasionally attack human beings, they do
10,000 years ago, when they were progressively dis- not rely on people to complete their lifecycles. Examples
placed or eliminated by the competition of larger soci- include tularemia, zoonotic tuberculosis, trichinosis, and
eties. (A few foraging groups continued into the twentieth occasional bubonic plague and other arthropod-borne
century as outliers of civilizations.) diseases such as sleeping sickness and malaria. Such
Despite stereotypes, such groups commonly enjoyed zoonotic diseases, because they don’t depend on human
relatively good nutrition and freedom from parasites. survival for their own survival, are often severe and mor-
They utilized a wide range of fresh foods, both animal tal; on the other hand, they only attack one or a few peo-
and vegetable, minimally processed, and exploited a rel- ple at a time because they do not spread from person to
atively large range of soil regimes, providing qualitatively person. Some infections maintained in soil can also infect
balanced diets. Comparatively few nutritional deficiencies small isolated human groups. Diseases that require high
are observed in historic remnant populations or in con- population density, sedentism, large human communities,
temporary ones, or in prehistoric skeletons. Historic and transportation networks could not have survived.
hunter-gatherers are commonly better nourished than
their sedentary, farming, and civilized counterparts and Farming and
far better nourished and less parasite-ridden than the Larger Groups
modern poor. Calories may have been the limiting nutri- The adoption of agricultural and animal domestication
ent. However, because meat was lean, the intake of calo- both permitted and necessitated sedentism and larger
ries, fats, sugars, salts, and dietary carcinogens was low, group sizes. Concentrated food supplies permitted higher
and because foragers lived in an environment free of population densities and larger settlements. Sedentism
industrial pollutants, they escaped many of the scourges had obvious advantages: It assisted the survival of babies,
of twentieth-century populations (obesity, heart disease, the sick, the wounded, and the elderly by reducing the
hypertension, diabetes, and cancers). need for mobility and providing boiled food for the
Low population density, small group size, and frequent toothless. (Sedentary populations can keep and use pot-
movement tended to minimize the number of parasites tery but mobile populations cannot.) Stored resources
that could complete their lifecycles. (Many parasites are can help mitigate food shortages and crop failures. Seden-
density-dependent and reliant on human sedentism, on tism also seems to have increased human fertility and
the size of human communities, and on poverty created altered birth-control choices, accelerating population
by civilization.) And good health among foragers appears growth. (There is little evidence to suggest that life ex-
to have been commonly accompanied by a reasonably pectancy increased and it may in fact have decreased.)
high life expectancy (that is, the average age at death But sedentism also necessitated a heavy investment in
among members of a group) of twenty-five to thirty seasonal crops, permanent fields, and storage.