Doctoral Dissertation Research: The role of thermoregulation in the obstetrical dilemma

在人类分娩过程中，婴儿在产道中非常紧密，人类学家有兴趣了解是什么进化压力导致了女性骨盆的大小和形状，从而导致分娩困难。这个项目将测试体温调节假说，该假说认为人类骨盆的宽度受到保持一个善于保持凉爽的狭窄身体的需要的限制。人类祖先在温暖的气候中进化，从事艰苦的活动，狭窄的身体有助于温度调节。将收集关于骨盆尺寸的skeleton数据和来自活人的温度调节数据，以解决温度调节假说。这些数据也可能是预测妇女在梗阻性分娩的风险和预防过热的娱乐和专业运动员的信息。此外，该项目将支持STEM培训两名女本科生，她们来自科学领域代表性不足的群体。项目成果将在当地高中和美国自然历史博物馆与公众分享。“产科困境”的传统解释是，为什么现代人类女性的产道没有扩大，使分娩更容易，狭窄的骨盆在双足运动时更有效率。然而，温度调节假说，这表明，一个狭窄的骨盆有助于在身体活动期间的温度调节，已被讨论作为一个竞争的假说。这项研究将探讨温度调节在限制产道发育中的潜在作用。研究人员假设，在现代人类的身体活动中，狭窄的骨盆有助于体温调节，髋关节宽度与产道面积相关，直立人是一种身体狭窄、热适应的分类。研究人员将收集跑步者的体温调节数据，以确定狭窄的骨盆是否在运动中赋予体温调节优势;测量女性骨盆尺寸使用三维扫描创建从生态地理不同的人群;并重建KNM-WT 15000 H。直立人骨盆，这是有争议的，因为最初的重建提供了唯一的证据，在智人进化之前，人类有一个狭窄的骨盆。这些数据将有助于更广泛地了解梗阻性分娩背后的进化原因。

In human childbirth, the baby fits very tightly in the birth canal, and anthropologists are interested in understanding what evolutionary pressures may have led to a female pelvic size and shape that can contribute to difficult childbirth. This project will test the thermoregulation hypothesis, which suggests that the width of the human pelvis is limited by the need to maintain a narrow body that is good at staying cool. Human ancestors evolved in warm climates and engaged in strenuous activities, and a narrow body aids in temperature regulation. Skeletal data on pelvic dimensions and temperature regulation data from living people will be collected to address the thermoregulation hypothesis. These data may also be informative for predicting women at risk of obstructed labor and for preventing overheating in recreational and professional athletes. Additionally, this project will support STEM training for two female undergraduate students from groups underrepresented in science. Project results will be shared in local high schools and with the general public at the American Museum of Natural History.The traditional explanation for the "obstetrical dilemma," which asks why the modern human female birth canal has not expanded to make birth easier, is that a narrow pelvis is more efficient during bipedal locomotion. However, the thermoregulation hypothesis, which suggests that a narrow pelvis aids in thermoregulation during physical activity, has been discussed as a competing hypothesis. This research will investigate the potential role of thermoregulation in constraining the evolution of the birth canal. The investigators hypothesize that a narrow pelvis aids in thermoregulation in modern humans during physical activity, that hip breadth is correlated with the area of the birth canal, and that Homo erectus was a narrow-bodied, heat-adapted taxon. The investigators will collect thermoregulation data from runners to determine if a narrow pelvis bestows thermoregulatory advantages during exercise; measure female pelvic dimensions using three-dimensional scans created from eco-geographically varied populations; and reconstruct the KNM-WT 15000 H. erectus pelvis, which is controversial because the original reconstruction provides the only evidence of a hominin with a narrow pelvis prior to the evolution of Homo sapiens. These data will contribute to a broader understanding of the evolutionary reasons behind obstructed labor.