This thesis investigates how to determine the season of death of animals from seasonal growth bands in dental cementum (cementum increment analysis) and applies this technique to estimating the seasonal mobility of hunter-gatherers in the southern Levant during the Late Pleistocene. The evidence for the season of occupation of archaeological sites from the southern Levant suggests that a strategy of high seasonal mobility may be a quintessential adaptation of modern human hunter-gatherers. For almost 100,000 years hunter-gatherers in the southern Levant migrated from the highlands in the dry season to the lowlands in the wet season. This pattern contrasts with evidence that Neanderthals (who lived in the same region under similar conditions) may have been less seasonally mobile than modern humans -- a behavioral strategy that may explain many of the physiological differences between the two taxa. The modern human strategy of high seasonal mobility persisted in the Levant until the end of the Ice Age when a group of hunter-gatherers known as the Natufians became sedentary. The adoption of reduced seasonal mobility by the Natufians most likely contributed to the origins of agriculture.

The season of occupation of archaeological sites can best be estimated from data on the season of death of mountain gazelle (Gazella gazella) and other mammals derived from incremental structures in their teeth. Cementum, a dental tissue that surrounds the tooth root, is composed of bands (visible in transmitted polarized light) that correspond in most species to seasonal growth. Controlled laboratory experiments on goats demonstrate that seasonal bands in dental cementum are caused by two factors related to seasonal diets. Most importantly, changes in the magnitude and frequency of strain (deformation) caused by chewing diets of different hardness or quality alter the orientation of both the intrinsic and extrinsic (Sharpey's fiber) collagen fibers in cementum bands, thereby resulting in the optical phenomenon of banding in polarized transmitted light. In addition, changes in the nutritional content of diets in different seasons can affect the rate at which cementum bands are deposited, thereby altering the density of mineral in cementum bands.