Doctoral Dissertation Research: Selection pressures on skull and pelvis proportions at birth

出生是所有人类都必须经历的过程;然而，即使有现代医疗干预，这对母亲和婴儿来说也是危险的，可能是致命的。这个博士论文项目研究了各种猴子和猿的头骨和骨盆形状的演变，以更好地了解不同灵长类谱系中分娩困难的方式和时间，并更好地确定人类面临的困难是否是我们物种所独有的，或者是我们的分类顺序所共有的遗产。该项目促进女科学家的研究生培训，并可使医疗专业人员更深入地了解人类分娩的困难。由于产道与婴儿头骨之间的紧密配合，现代人类分娩比其他大型猿类如黑猩猩和大猩猩更危险，更容易导致婴儿或母亲死亡。因此，难产在历史上被认为是人类特有的进化特征，可能源于骨盆对直立行走的适应和异常大的大脑的进化。然而，据报道，体型较小的灵长类动物，如小型猿和一些猴子，在分娩过程中会出现严重的并发症，包括产妇和婴儿死亡。这就提出了一个问题，即人类是否因为与体型较小的灵长类动物相同的原因而经历困难的分娩，或者人类的困难分娩实际上是独一无二的。为了解决这个问题，该项目调查了灵长类动物头骨和骨盆的进化和自然选择模式，特别是在分娩的关键区域，利用3D扫描数据将头骨和骨盆的形状差异的模式和大小与基于猿和猴物种之间广泛样本的遗传关系所预期的模式和大小进行比较。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来提供支持。

Being born is a process all humans must experience; however, even with modern medical intervention, it is risky and potentially fatal for both mother and infant. This doctoral dissertation project examines the evolution of skull and pelvis shape in a wide range of monkeys and apes to better understand how and when birthing difficulties may have arisen in different primate lineages, and better determine whether the difficulties faced by humans are unique to our species or a legacy shared by our taxonomic order. This project fosters graduate student training of a female scientist and can provide a deeper understanding of the difficulty of human childbirth for medical professionals. Results of this research are communicated to the public through popular science outlets.Due to the tight fit between the birth canal and the infant skull, modern human childbirth is more dangerous and more likely to result in death for the infant or mother than in other large-bodied apes like chimpanzees and gorillas. As a result, difficult childbirth has historically been thought of as an evolved trait unique to humans, possibly stemming from the combination of pelvic adaptations to walking upright and the evolution of unusually large brains. However, smaller-bodied primates, such as the lesser apes and some monkeys, have been reported to experience serious complications, including maternal and infant death, during labor. This raises questions about whether humans experience difficult births for the same reason as smaller-bodied primates, or if difficult birth in humans is, in fact, unique. To address this question, this project investigates patterns of evolution and natural selection in the primate skull and pelvis, particularly in regions critical to childbirth, using 3D scan data to compare the patterns and magnitude of shape differences in the skull and pelvis to those expected based on genetic relationships among a wide sample of ape and monkey species.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.