Weisensee Katherine E, Jantz Richard L
1 Department of Sociology and Anthropology, Clemson University, Clemson, South Carolina.
2 Department of Anthropology, University of Tennessee, Knoxville, Tennessee.
Hum Biol. 2016 Jan;88(1):30-37. doi: 10.13110/humanbiology.88.1.0030.
This research examines 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. The two samples examined in this study come from US and Portuguese individuals. 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 US 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 changes significantly over time. However, the pattern of change in the US and Portuguese samples varies in the other regions of the crania. The US samples exhibit significant changes associated with the posterior cranial fossa, which experiences the greatest growth during the fetal period and the first year of life. Conversely, in the Portuguese samples the region of the cranium that shows the greatest change is in the face and lateral cranial base, which experiences the greatest growth from three to nine years. 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 exhibit the greatest changes occur in area with maximum growth velocity under one year. However, Portugal entered into the epidemiological transition later than the United States and therefore the greatest changes in growth occurred during the juvenile period, which is reflected in the adult morphology in this group. 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.
本研究考察了两个人口群体颅骨形态的长期变化模式，这两个人口群体正经历与儿童死亡率下降相关的流行病学转变，随后婴儿死亡率下降，成人寿命增加。本研究中考察的两个样本分别来自美国人和葡萄牙人。流行病学转变在美国和葡萄牙发生的时间不同，葡萄牙比美国更晚进入这一转变阶段。研究结果表明，在大约150年的研究期内，美国和葡萄牙的样本颅骨形态发生了显著变化。在所有样本中，颅底形态随时间发生了显著变化。然而，美国和葡萄牙样本在颅骨的其他区域的变化模式有所不同。美国样本显示出与后颅窝相关的显著变化，后颅窝在胎儿期和生命的第一年生长最为显著。相反，在葡萄牙样本中，颅骨变化最大的区域是面部和外侧颅底，其在3至9岁时生长最为显著。这种差异模式可能反映了两国死亡率变化模式的差异。在研究期间，美国已经经历了流行病学转变的早期阶段，青少年死亡率和青少年生长情况此前已经有所改善。随后，美国婴儿死亡率显著下降，颅骨变化最大的区域出现在一岁以下生长速度最快的部位。然而，葡萄牙比美国更晚进入流行病学转变阶段，因此最大的生长变化发生在青少年时期，这反映在该群体的成人形态上。这项研究证明了不同颅骨区域生长模式的变化在记录两个不同人群人口统计学参数变化方面的作用。
