Envolution around 1,000 AD

The Globe

Type AB blood is rare, found in less than five percent of the population, and apparently only came into existence 1,000 to 1,200 years ago. (Gods, Genes, and Consciousness)



Southwest Asia




Indus Valley






South America




North America

Another example of paleopathologists at work is the study of thousands of American Indian skeletons excavated from burial mounds in the Illinois and Ohio river valleys. Corn, first domesticated in Central America thousands of years ago, became the basis of intensive farming in those valleys around 1000 AD. Until then, Indian hunter-gatherers had skeletons "so healthy it is somewhat discouraging to work with them," as one paleopathologist complained. With the arrival of corn, Indian skeletons suddenly became interesting to study. The number of cavities in an average adult's mouth jumped from fewer than one to nearly seven, and tooth loss and abscesses became rampant. Enamel defects in children's milk teeth imply that pregnant and nursing mothers were severely undernourished. Anemia quadrupled in frequency; tuberculosis became established as an epidemic disease; half the population suffered from yaws or syphilis; and two-thirds suffered from osteoarthritis and other degenerative diseases. Mortality rates at every age increased, with the result that only 1 percent of the population survived past age fifty, as compared to 5 percent in the golden days before corn. Almost one fifth of the whole population died between the ages of one and four, probably because weaned toddlers succumbed to malnutrition and infectious diseases. Thus corn, usually considered among the New World's blessings, actually proved to be a public-health disaster. Similar conclusions about the transition from hunting to farming emerge from studies of skeletons elsewhere in the world. (The Third Chimpanzee)