Doctoral Dissertation Improvement: A Comparative Study of Catarrhine Bone Microstructure and Life History

生命史是指物种特有的繁殖模式，以及它们的成员生长、成熟和死亡的时间表和过程。旧大陆猴子和猿的生活史策略的进化和多样化，以及人类独特的生活史模式的起源，是人类学家的主要兴趣。为了将研究扩展到已灭绝的灵长类动物，包括原始人，一个重点是鉴定可以在骨骼和牙齿化石中识别的生活史的解剖“特征”。迄今为止，大多数研究都集中在牙齿发育的各个方面（例如，牙釉质近每周的微观增量），这反映了个体的生长模式。然而，对其他脊椎动物的大量研究表明，骨组织中的微观结构构成了关于生命史的另一个重要信息来源，从而扩大了化石研究的基础。目前的研究旨在研究生活史对中轴股骨和肱骨的微观结构组织发育的影响，重点是由长尾猴、白掌长臂猿和普通黑猩猩组成的有限比较样本。使用新的显微镜技术，本研究的具体目的是：1)描述和量化几种已知反映个体生长模式的骨骼微观特征的可变性；2)评估微观结构变量与更传统的产后生长指标（如已知体重、骨长和出牙）的对应关系；3)确定骨微观结构变量的物种差异是否反映生活史差异；4)考虑与骨骼功能相关的骨骼变化对生命史解释的影响。如果骨骼微观结构在现代动物生活史方面的鉴别潜力得到确立，这一方法可能有助于我们理解灵长类动物生活史策略的进化和多样化，包括早期原始人的生长模式及其古环境。

Life history refers to the reproductive patterns characteristic of species, and the schedule and processes by which their members grow, mature, and die. The evolution and diversification of life history strategies among Old World monkeys and apes, and the origin of the unique life history pattern characteristic of humans, is a major interest of anthropologists. To extend investigations to extinct primates, including hominids, a focus has been the identification of anatomical "signatures" of life history that can be recognized in fossilized bones and teeth. The majority of studies to date have focused on aspects of dental development (e.g., microscopic near-weekly increments in enamel) that reflect the growth patterns of individuals. However, numerous studies of other vertebrates have demonstrated that microscopic structures in bone tissue constitute another important source of information about life history, thus expanding the foundation for studies of fossils. The current study is designed to examine the influence of life history on the developing micro-structural organization of the midshaft femur and humerus, focusing on a restricted comparative sample comprised of growth series of vervet monkeys, white-handed gibbons, and common chimpanzees. Using novel microscopy techniques, the specific aims of this study are: 1) to describe and quantify variability in several microscopic features of bone known to reflect individual growth patterns; 2) to assess the correspondence of micro-structural variables with more traditional measures of postnatal growth (e.g., known body weight, bone length, and dental eruption); 3) to determine whether species differences in bone micro-structural variables reflect life history variation; and 4) to consider the influence of changes in bone related to skeletal function on interpretations of life history. If the potential of bone micro-structure for discriminating aspects of life history is established in modern animals, this approach may contribute to our understanding of the evolution and diversification of life history strategies among primates, including the growth patterns of early hominids and their paleoenvironments.