Abstract

Background

Previous studies of secular change in cranial size among black South Africans have produced conflicting results.

Aim

We re-examined cranial size change in this population during the 19th and 20th century by evaluating its relationship with individual year-of-birth, and the significance of trends among eight decennial cohorts.

Subjects and methods

This study is based on 102 male and 89 female adults born between 1865 and 1959. Linear regressions were employed to evaluate possible relationships between year-of-birth and cranial dimensions; ANOVAs were used to evaluate the significance of long-term trends among decennial cohorts.

Results

No analysis revealed a secular change in cranial length in either sex; however, the ANOVA for cranial length in the combined sex sample was significant. There is no secular trend in female cranial breadth, but males display a negative trend in this dimension. This results in a secular trend for increased male dolichocephaly.

Conclusions

The factors that underlie the negative secular trend in male cranial breadth and the absence of a secular trend in overall cranial size in this population are unclear. Nevertheless, these observations accord with findings related to stature and long bone strength in this population and are consistent with observations for other sub-Saharan African populations.

中文翻译：

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19世纪末和20世纪末，南非黑人的颅骨大小和形状呈长期趋势。

摘要

背景

先前关于黑人黑人颅骨大小长期变化的研究得出了相互矛盾的结果。

目标

我们通过评估19岁和20世纪该人群与个别出生年份的关系以及8个十年期人群中趋势的重要性，重新检查了该人群的颅骨大小变化。

主题与方法

这项研究基于1865年至1959年之间出生的102位男性和89位女性成年人。线性回归用于评估出生年与颅骨尺寸之间的可能关系。方差分析用于评估十年期队列中长期趋势的重要性。

结果

没有分析显示两性的颅骨长度发生长期变化。然而，合并性别样本中颅骨长度的方差分析很显着。女性的颅骨宽度没有长期趋势，但是男性在这个方面显示出负面趋势。这导致了男性多头畸形的长期趋势。

结论

目前尚不清楚该人群中男性颅宽呈负长期趋势的原因以及颅骨总体大小没有长期趋势的原因。然而，这些观察结果与该人群的身高和长骨强度相关的发现相符，并且与其他撒哈拉以南非洲人群的观察结果一致。