Skull shape and emergence of agriculture
Human skull image: Courtesy BernardBill5
A study* indicates that the transition from foraging to farming was associated with modest but functionally relevant changes in the shape of the human skull. Previous studies indicate that the shape of the human skull changed with the emergence of agriculture, likely due to the increased availability of soft foods. However, determining the consistency and extent of changes in skull shape at a global scale has proven difficult. Based on a worldwide collection of 559 crania and 534 mandibles from more than two dozen preindustrial populations, David Katz and colleagues modeled the influence of diet on the shape, form, and size of the human skull during the transition to agriculture. The authors analyzed the importance of cereals and dairy, two common agricultural staples, and identified modest changes in skull morphology for groups that consumed cereals, dairy, or both cereals and dairy, supporting the hypothesis that the practice of chewing food decreased in farming populations. The largest changes in skull morphology were observed in groups consuming dairy, suggesting that the effect of agriculture on skull morphology was greatest in populations consuming the softest food. According to the authors, morphological differences due to diet tended to be small relative to other factors that contribute to human skull variation, such as differences between males and females or typical differences between individuals with the same diet but from different populations.
Skull landmarks. Courtesy David C. Katz, et al.*
*“Changes in human skull morphology across the agricultural transition are consistent with softer diets in preindustrial farming groups,” by David C. Katz, Mark N. Grote, and Timothy D. Weaver. Available at http://www.pnas.org/cgi/doi/10.1073/pnas.1702586114