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AGRICULTURE AND ANIMAL DOMESTICATION One of the seminal events in human history is the domestication of certain animals and plants. In her recent paper on the relationship between humans and domesticated plants and animals, Melinda Zeder defined domestication as follows: “Domestication is a sustained multigenerational, mutualistic relationship in which one organism assumes a significant degree of influence over the reproduction and care of another organism in order to secure a more predictable supply of a resource of interest, and through which the partner organism gains advantage over individuals that remain outside this relationship, thereby benefitting and often increasing the fitness of both the domesticator and the target domesticate.” As this definition points out, domestication can be viewed as a mutualistic relationship, benefiting both partners. When we began to selectively breed particular individuals with certain traits, humans were, at a fundamental level, changing allele frequencies, and thus causing evolution, in food animals and plants. ftis process is now known as artificial selection. ftousands of years after the beginnings of domestication, Charles Darwin used this selection by humans as an analogy for how certain alleles are best able to survive and flourish in natural populations. He called this mechanism of evolution “natural selection.” Somewhat surprisingly to many, human domestication of animals appears to have preceded plant domestication. ftere is disagreement on the exact date, but molecular genetic evidence suggests that the modern dog diverged from wolves at least 40,000 years ago which, presumably, corresponds to the timing of dog domestication. Other animals were domesticated much later. Pigs were domesticated roughly 15,000 years ago, sheep and goats about 12,000 years ago, and cattle around 10,000 to 11,000 years ago. Until recently, the earliest evidence of plant domestication was thought to be about 10,000 to 12,000 years ago, in the form of wheat and barley cultivation. ftis took place in the area known as the “Fertile Crescent,” or Mesopotamia, the region that includes present-day Iraq, Kuwait, and parts of Iran, Turkey, and Syria (Fig. 8.7). However, recent studies done by Ainit Snir and colleagues at the Ohalo II site on the shore of the Sea of Galilee, Israel provide evidence of agricultural cultivation 23,000 years ago. Figure 8.7: The Fertile Crescent. (Wikipedia ‘Fertile Crescent;’ Attribution: Nafsadh) Many of our domesticated crops are the descendants of “weedy” species that colonize and grow well in disturbed soils. ftere is archaeological evidence from over 20,000 years ago of dough made from wild wheat, barley, and other grass species. It would have been a relatively small leap from taking advantage of these wild plants for food, to collecting and storing their seeds and then distributing them in soil previously disturbed for this purpose. Of course, variation in these plants meant that some had more desirable characteristics than others, and in time people learned to select for desirable traits. Other plants, such as pea, beans, alfalfa, and lentil were also domesticated in Mesopotamia. Centers of agriculture in other geographic regions developed a bit later – in China and the Americas beginning about 8,000 years ago, and Africa beginning about 7,000 years ago. However, there is some evidence of taro cultivation in Papua New Guinea almost 30,000 years ago, which would make this plant the first in the world to be cultivated. fte Agricultural Revolution, also known as the Neolithic Demographic Transition or the Neolithic Revolution, marked the transition of human populations from primarily scattered, hunter-gatherer societies to larger, more concentrated groups. ftis resulted from high agricultural productivity which produced enough food to support denser populations. Humans became less nomadic, and food surpluses made it possible for some people to work at non-food production activities, allowing better development of a variety of skills and new technologies. ftis led to a greater degree of specialization and to more organized, hierarchical societies. fte standard view is that the development of agriculture marked the beginning of a dramatic increase in the quality of human life. After all, plentiful food could now be had without all the hard work associated with hunting game and gathering plant foods. But recently, some have begun to question the accuracy of this view. Evidence now suggests that hunter-gatherers can meet their food requirements in fewer work hours than can agriculturalists. Agriculturalists’ diets are also apparently less balanced and of lower quality than that of hunter-gatherers. Evidence shows that the stature of early Europeans after the change to agriculture decreased by 4 to 5 inches, from 5'10" (men) and 5'6" (women) to 5'5" and 5'1", respectively. Agriculture led to the development of vitamin deficiencies and teeth and bone problems. fte close association with their domesticated animals also led to spread of diseases such as measles, influenza, smallpox, tapeworms, and Trichinella from animals to humans. Living a sedentary lifestyle in close proximity to their own feces also led to increased prevalence of parasites such as hookworms and other intestinal roundworms. Some have argued that the development of agriculture led to change from more egalitarian hunter-gatherer societies to highly stratified societies with concentration of wealth and power in a few hands, and high levels of inequality. fte above deficiencies of agriculturally-based diets generally applied only to the poor and working class; the smaller number of wealthy, non-producing elites of the agricultural world were much healthier. Many of the problems associated with agrarian societies were reviewed by Jared Diamond in a 1987 Discover magazine article descriptively titled “fte Worst Mistake in the History of the Human Race.” Whatever the costs and benefits of the agricultural way of life, the development of agriculture inevitably led to the displacement of hunter-gatherer societies. fte large, concentrated populations associated with agrarian societies have, to a great extent, pushed their hunter- gather counterparts aside, and agriculture has overwhelmingly shaped the pathway that humanity has taken. ftat pathway has led to dramatic inequalities among human societies. In particular, Eurasian societies have come to gain hegemonic dominance over the modern world. Some ascribe this dominance to superior intelligence, talent, skill, or morality. But in his Pulitzer Prize-winning book Guns, Germs, and Steel: The Fates of Human Societies, Jared Diamond proposed a controversial new hypothesis to explain the roots of these inequalities. Diamond asserts that these inequalities are best explained by fundamental geographic and environmental differences rather than inherent Eurasian superiority. Download free eBooks at bookboon.com 153 Diamond argues that Eurasian success has been due, to a great extent, to the geographic “luck of the draw.” With the rise of agriculture, Eurasians possessed early advantages in the availability of large numbers of plants and animals suitable for domestication. Eurasians had food plants such as wheat, barley, and edible legumes that were relatively nutrient rich, and easier to plant and cultivate than food plants in other regions of the world. Similarly, Eurasians had large numbers of animals such as sheep, goats, and cattle that had suitable behaviors, diets, and growth rates for domestication. Large mammals in particular are useful, not only for food, but in providing muscle power as beasts of burden. Diamond lists 14 large mammals worldwide that have been domesticated; of these all but two are descendants of wild species found in Eurasia, including the five most useful – sheep, goats, cows, pigs, and horses. Eurasia’s long east-west axis was also advantageous in that it increased the likelihood of domesticated plants and animals from one location being well suited for other locations with similar latitudes and climates. ftese advantages in numbers of species suitable for domestication would translate into large advantages in food production, division of labor, long distance transport of materials, and economic and military superiority. ftis in turn would lead to the development of powerful nation-states and empires that would come to dominate most of the world. fte Eurasian advantage in animal domestication would have other ramifications as well. fteir long, close association with domesticated animals meant that Eurasians had long exposure to a variety of parasites and pathogens, to which they evolved some immunity. When Europeans invaded the New World, they carried some of these pathogens with them. fte indigenous people had never been exposed to these diseases, and had little immunity to them. fte most devastating of these diseases was smallpox, but other diseases such as measles, cholera, and influenza caused many deaths as well. fte number of indigenous people in the New World before the arrival of Europeans is unclear; estimates range from about 10 million to 100 million or more. After European contact, this number declined by 70 to 90%, mostly due to disease. Diamond makes compelling arguments for the importance of geographic determinism in explaining the roots of human inequality. However, counterarguments can be made as well. ftere are exceptions to Diamond’s examples; geographic locations where the conditions for agricultural development were excellent, but intensive agriculture never developed, and cultures that did develop efficient agriculture but still remained poor. ftere are many factors in addition to geography that can play a role in the development of societies, and the relationship between human success and their geographic setting is not a one-way street; humans are adaptable, and capable of altering their surroundings to suit their purposes.
Kategoria: Moje artykuły | Dodał: kolo (2019-03-11)
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