Human Biology Volume: 88 Issue: 1 Dated: Winter 2016 Pages: 30-37
The reported research examined the pattern of secular change in the cranial morphology of two populations experiencing the epidemiological transition associated with decreased mortality rates in children, followed by declines in infant mortality and subsequent increases in adult longevity.
Overall, this study demonstrates the utility of variation in growth patterns in different cranial regions to document changes in the demographic parameters in two different populations. The two samples examined in this study come from the United States and Portugal. The epidemiological transition occurred at different times in the United States and Portugal, with Portugal entering into the transition later than the United States. The results of the study show that the U.S. and Portuguese samples experienced significant changes in cranial morphology during the approximately 150 years under study. In all of the samples the cranial base morphology changed significantly over time; however, the pattern of change in the United States and Portuguese samples varied in the other regions of the crania. The U.S. samples exhibited significant changes associated with the posterior cranial fossa, which experienced the greatest growth during the fetal period and the first year of life. Conversely, in the Portuguese samples, the region of the cranium that showed the greatest change was in the face and lateral cranial base, which experienced the greatest growth from 3 to 9 years old. This differential pattern may reflect differences in changing mortality patterns in the two countries. During the period under study, the United States had already proceeded through the early stages of the epidemiological transition, and improvements in the juvenile mortality and juvenile growth had occurred previously. Subsequently, the United States experienced significant declines in infant mortality, and the regions of the crania that exhibited the greatest changes occurred in areas with maximum growth velocity under 1 year; however, Portugal entered into the epidemiological transition later than the United States; therefore, the greatest changes in growth occurred during the juvenile period, which was reflected in the adult morphology in this group. (Publisher abstract modified)
Report (Grant Sponsored)
Date Published: January 1, 2016