I found very interesting in the text, the discussion about the impact of the agricultural revolution and its effects on infectious disease. While, I feel that in the West the agricultural revolution is still largely hailed as a step towards civilization, it was as well a step towards the epidemic diseases we still live with. Early humans were not sedentary, following practices of hunting and gathering, they moved around following food and did not establish large urban areas. The authors of the text note that the pathogens that effected early humans were ectoparasites, protozoa, fungi, bacteria, and zoonotes (diseases that transfer between species, ex. Tuberculosis from cattle to humans (p. 257)). These pathogens usually do not lead to epidemics and spread slowly through populations (p. 255). With the advent of agriculture as well came sedentary populations that begin to live in much large population densities than are seen among hunter-gatherer groups. As well, dealing with human waste, which was not an issue for mobile hunter-gatherer groups, becomes a major potential health risk for urbanized populations. With the rise of more domestication of animals came more zoonotes. Diets became less balanced, and malnutrition became more widespread. The rise of trade helped to spread diseases through in between distant populations. These conditions are conducive to the rise of things like plague or smallpox that have the potential to erupt into major epidemics with the potential to kill mass amounts of people (p. 256-59). While we have been able to control many deadly epidemic disease such as smallpox for some years, the threat of resistant strains may result in massive epidemics in the future.