The shift by early Native Americans from a hunter-gatherer culture to an agricultural community produced a sharp growth in population, but it also led to an increase in infectious and nutritional diseases, according to anthropologist George J. Armelagos of the University of Massachusetts at Amherst.
Armelagos has been studying the Dickson Mound, which is located in Illinois near the confluence of the Spoon and Illinois Rivers. The Mound is the site of a community that developed and intensified agriculture from A.D. 900 to 1250.
Studies of bones from the site show that "the later agricultural populations suffered a four-fold increase in iron deficiency anemia and a three-fold increase in infectious disease," he said. "There is also evidence that the farmers' long bones were growing slower and individuals were dying at a faster rate."
Armelagos attributed the increase in infectious disease to the fact that fecal wastes were deposited near the group's water supply, making it easier for germs to pass from person to person.