Moffett Elizabeth A
Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri.
Department of Anthropology, Stony Brook University, Stony Brook, New York.
Anat Rec (Hoboken). 2017 May;300(5):870-889. doi: 10.1002/ar.23572.
It has long been noted that the human female birth canal is well adapted to giving birth to large-brained neonates. However, several species of nonhuman primates give birth to large-headed neonates compared to the maternal birth canal. The presence of such large cephalopelvic proportions in nonhuman primates presents the question of whether dimorphism in the birth canals of these other species is related to obstetric demand, as such dimorphism is presumed to be in humans. In this study, the hypothesis that either the presence or magnitude of dimorphism in the birth canal is related to large cephalopelvic proportions among anthropoid primates is directly tested. This study shows that birth canal dimorphism is common among anthropoids regardless of cephalopelvic proportions, but taxa with large cephalopelvic proportions have a higher magnitude of dimorphism than those that give birth to relatively small-headed neonates. Furthermore, humans have exceptionally high levels of dimorphism that cannot be explained based on our large cephalopelvic proportions alone. Anat Rec, 300:870-889, 2017. © 2017 Wiley Periodicals, Inc.
长期以来，人们一直注意到人类女性的产道非常适合分娩大脑袋的新生儿。然而，与母体产道相比，几种非人类灵长类动物会产出头部较大的新生儿。在非人类灵长类动物中存在如此大的头盆比例，这就提出了一个问题：这些其他物种产道的二态性是否与产科需求有关，就像人们认为人类的二态性与产科需求有关一样。在这项研究中，直接检验了这样一个假设，即产道二态性的存在或程度与类人猿灵长类动物中大的头盆比例有关。这项研究表明，无论头盆比例如何，产道二态性在类人猿中都很常见，但头盆比例大的分类群比那些产出相对小头新生儿的分类群具有更高程度的二态性。此外，人类具有极高的二态性水平，仅基于我们大的头盆比例无法解释这一点。《解剖学记录》，300:870 - 889，2017年。© 2017威利期刊公司。
