Doctoral Dissertation Research: Encephalic Arterial Canals and their Functional Significance

进化出一个像人类大脑这样的大大脑的成本被假设为需要能量的权衡，这样大脑代谢的增加可能需要减少用于生长和繁殖的能量。然而，需要更多关于大脑代谢（能量使用率）的比较数据，以更好地研究这些潜在的权衡。由于直接测量是很难获得的大多数活的物种和灭绝的不可能的，这个博士论文项目将使用测量从骨骼特征受大脑代谢需求的影响，推断大脑代谢率在一个广泛的哺乳动物群体。比较哺乳动物消耗在大脑上的能量相对于身体代谢的变化方式和原因，将促进灵长类动物和人类生物学以及大脑进化方面的知识。该项目将生成大量头骨的3D扫描，用于杜克大学和北卡罗来纳州自然科学博物馆的学生指导和公众宣传。这些数据也将在数字档案MorphoSource上公开发布，这将产生进一步的研究和教育效用。以前的研究表明，传输大脑动脉的孔的大小可以用来预测真古生物的大脑葡萄糖利用率。该项目旨在进一步评估这些孔的使用，以测试大脑大小进化的有力假设。横突孔（传输椎动脉）和颈动脉管（传输颈内动脉）的直径将分别从高分辨率计算机断层扫描获得的骨骼学和3-D数字化标本中测量，这些标本分别来自有袋动物，glirans，afrotheres，xenarthrans和一些食肉动物的广泛分类样本。还将在人类尸体骨骼学样本中进行骨管面积和通过个体发育预测的血流量变化的研究，以进一步阐明椎间孔大小、脑大小和脑代谢之间的关系。利用这些数据，该项目将测试灵长类动物和其他哺乳动物的大大脑在多大程度上是通过增加身体的代谢率来维持的。这项研究将进一步了解人类大脑进化的背景下，哺乳动物的大脑evolution.This奖项反映了美国国家科学基金会的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

The cost of evolving a large brain, like the human brain, is hypothesized to require energetic trade-offs, such that increases in brain metabolism may require reductions in energy used for growth and reproduction. However, additional comparative data on brain metabolism (the rate at which energy is used) are needed to better investigate these potential trade-offs. Because direct measurements are difficult to obtain for most living species and impossible for extinct ones, this doctoral dissertation project will use measurements obtained from skeletal features affected by brain metabolic demands to infer rates of brain metabolism in a broad group of mammals. Comparing how and why mammals may vary in the energy they expend on the brain relative to their body's metabolism will advance knowledge in primate and human biology and brain evolution. This project will generate numerous 3D scans of skulls that will be used for student mentoring and public outreach at Duke University and the North Carolina Museum of Natural Sciences. These data will also be released for public access on the digital archive MorphoSource, which will yield further research and educational utility.Previous studies suggest that the size of foramina that transmit the brain's arteries may be used to predict brain glucose utilization rates in euarchontans. This project aims to further evaluate the use of these foramina to test energetic hypotheses of brain size evolution. Diameters of the transverse foramina (which transmit the vertebral artery) and carotid canals (which transmit the internal carotid artery) will be measured from osteological and 3-D digitized specimens obtained from high-resolution computed tomography scans, respectively, in a broad taxonomic sample of marsupials, glirans, afrotheres, xenarthrans, and some carnivorans. A study of bony canal area and predicted blood flow rate change through ontogeny in a cadaveric osteological sample of humans will also be conducted to further elucidate the relationship between foramen size, brain size, and brain metabolism. Using these data, this project will test the extent to which large brains in primates and other mammals are sustained by increasing the body's metabolic rate. This research will further the understanding of human brain evolution within the context of mammalian brain evolution.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.