the story of the human body evolution health and disease sparknotes

One reason is that many of these diseases have little to no effect on fertility. “Human evolution is not over, but the chances of natural selection adapting our species in dramatic, major ways to common non-infectious mismatch diseases are remote unless conditions change dramatically. ― quote from The Story of the Human Body: Evolution, Health, and Disease The term epidemiologists coined for this phenomenon is the “extension of morbidity.” In addition, many of the other leading causes of death today are chronic illnesses such as asthma, Alzheimer’s, type 2 diabetes, and kidney disease, and there has been an upsurge in the occurrence of nonfatal but chronic illnesses such as osteoarthritis, gout, dementia, and hearing loss.63 Altogether, the growing prevalence of chronic illness among middle-aged and elderly individuals is contributing to a health-care crisis because the children born during the post–World War II baby boom are now entering old age, and an unprecedented percentage of them are suffering from lingering, disabling, and costly diseases. Many cancer patients also remain alive for several years following their diagnosis because of chemo-therapy, radiation, surgery, and other treatments. Some heart attack victims die within minutes or hours, but most elderly people with heart disease survive for years while coping with complications such as high blood pressure, congestive heart failure, general weakness, and peripheral vascular disease. In contrast, the two most common causes of death in 2007 America were heart disease and cancer (each accounted for about 25 percent of total deaths).

The two most common causes of death in 1935 America were respiratory diseases (pneumonia and influenza) and infectious diarrhea, both of which kill rapidly. The downside is that he or she also should expect to die more slowly. Roosevelt signed the Social Security Act in 1935, old age was defined as sixty-five years, yet estimated life expectancy in the United States at the time was sixty-one years for males and sixty-four years for females.62 A senior citizen today, however, can expect to live eighteen to twenty years longer.

The story of the human body evolution health and disease sparknotes