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Chapter 1-2

Plagues and Peoples notes Ch.1-2.doc

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Health Studies
Caroline Barakat

Plagues and Peoples Notes Chapter 1 - Ancestors mostly from Africa or parts of Asia - Closely related to monkeys, who suffer similar parasites, fungi, etc - Monkeys can be infected by 15-20 species of malaria. Humans can be infected by 4. both can suffer from malaria from eachother - Tiny organisms like in tropical rain forests, not cool and dry so they can live on their own until host comes along - Human cultural evolution threw off biological evolution - People got smarter, made weapons  better survival and food supply - Evolutionary spurt called “orthogenic” - Language came next, making them more human - New parasites came in (or worms) that can infect humans by eating meat - Trypanosome (sleeping sickness) in Africa in antelope transferred to humans by testes fly. Lethal to humans within weeks - Balance because people herd  fly  back to people. Herds became prey of other adapted animals, not just people - Human population went up = rate of infection went up - Opportunities for transfer multiply with increase human density - If threshold surpassed  hyperinfection would lower population. - Humanity didn’t transform the ecological system as a whole - Prehumans and protohuman lagged behind the African population - 8000 b.c. human hunting groups expanded all around the globe - Cultural adaptation meant less need for bio adaptation - Humans left tropical rainforest and parasites for a while but that did not last - Humans did incredibly well in new environments - Easily exterminated large bodied animals within 1000 yrs - Populations from warm to cool = unlikely to encounter unfamiliar infection or parasites - Parasitic gradient: the further populations penetrated into the cold, the more survival depended on large plants and animals and balances with parasites became insignificant. Chapter 2 - As big game animal populations went down, so did human population - Simultaneously, climatic changes altered balance of nature - Ancient hunters had to readjust their habits  became omnivores again - Food resources of shore and sea were for the first time systematically expoited. (mollusk, fish, etc) - Certain groups of people learned that prolonged soaking could remove poisonous chemicals from olives and cassava. - Also learned that other vegetables could be more digestible by grinding, cooking or fermenting - Started agriculture and domesticating animals - While humans farmed, causing animals and plants to multiply, others were displaced. It reduced biological variety and made local plant and animal populations more uniform - Food chains shortened as humans reduced the roles of rival predators and reserved food for only homo sapiens - Weeding was important to eliminate rival species. There were 2 methods of remodeling natural environments: o Artificial flooding (drown out competing species) o Mechanical alteration (digging and plowing) - Slashing and burning of land was not as effective because seeds found their way back. - Shortening the food chain and multiplying restricted number of domesticated plants and animals created dense concentrations of potential food for parasites - Unlike dealing with weeds and large-bodied organisms, human intelligence remained only fumblingly effective in dealing with disease-causing organisms - Settling down to prolonged or permanent occupancy of a single village meant greater risk of parasitic invasion o Increase contact with feces as they accumulated allowed a variety of intestinal parasites to move from host to host o Risk of water contamination - hunting bands had less of a risk - Within a few hundred years, all the historically significant regions where valuable food c
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