Doctoral Dissertation Improvement: Morphological Integration in Primate Hands and Feet

博士论文改进：灵长类动物手脚的形态整合

• 批准号: 0647624
• 负责人: Daniel Lieberman
• 金额: $ 1.07万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0647624&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Improvement; Morphological; Integration

The hands and feet of haplorhine primates (apes and monkeys) have similar intrinsic proportions that tend to correlate with their habitat and mode of locomotion. For example, arboreal quadrupeds (e.g. New World monkeys) have hands and feet with long digits in relation to the palm or sole, and a relatively long first digit enabling a secure grasp on small arboreal supports. Suspensory primates such as gibbons hang below arboreal supports by combinations of forelimbs and hindlimbs, and their extremities have long, curved phalanges. Among terrestrial species, digitigrade quadrupeds (e.g. papionins) have short straight phalanges relative to the metapodials (metacarpals and metatarsals). Remarkably, even humans have similarly proportioned extremities, despite the fact that their hands and feet perform different functions. Human hands and feet are short in relation to the limbs, with short, robust metapodials, short lateral phalanges and a proportionately longer first digit (great toe and thumb). NSF support will allow Campbell Rolian to test whether these skeletal similarities between hands and feet in haplorhines are the result of selection for similar functions, or whether underlying developmental phenomena such as pleiotropy (when one gene locus affects multiple aspects of the phenotype) cause hand and foot bones to be more strongly correlated with each other than with other parts of the skeleton. Pleiotropic effects between hand and foot developmental genetic programs can have potentially conflicting roles in the evolution of digit morphology. When hand and foot digits evolve to perform similar locomotor functions, pleiotropy should facilitate correlated changes in morphology. However, when hand and foot digits evolve to perform separate functions, then pleiotropic effects may constrain the independent evolution of digital shape in the hands and feet. Campbell will collect morphometric data from the bones of the hands and feet of over 500 individuals from 13 taxa, selected to represent the diversity of locomotor behaviors and breadth of evolutionary relatedness among haplorhines. These data will be used to compare patterns of phenotypic covariation within and between species, testing hypotheses about the importance of function vs development in driving the independent evolution of digit morphology in primates.Significance and Broader Impacts: Few studies have addressed empirically how developmental constraints may bias natural selection for morphological divergence. Campbell will address this important question by looking at covariation in haplorhine hands and feet. Using primate limb skeletons as a case study, this project will provide broader insight into the patterns and processes of vertebrate morphological evolution, particularly as they relate to the growing field of evolutionary developmental biology (evo-devo). This project also has important implications for the study of human evolution. For instance, results may provide evidence that human hands and feet did not evolve their intrinsic proportions independently. Such information will be critical for testing long-standing hypotheses about the selective history of manipulative ability and bipedalism in the hominin lineage. Additional broader impacts of the study include providing teaching tools for undergraduate education, and the creation of a valuable digital archive of primate hand and foot skeletons. Through publications in peer reviewed journals and presentations at interdisciplinary conferences, this project will also help integrate graduate training and research in physical anthropology with evolutionary developmental biology.

哈普罗灵长类动物（猿和猴子）的手和脚具有相似的内在比例，这往往与其栖息地和运动方式相关。例如，树栖四足动物（例如新大陆猴）的手和脚的手指相对于手掌或脚底而言较长，并且第一根手指相对较长，可以牢固地抓住小型树栖支撑物。长臂猿等悬吊灵长类动物通过前肢和后肢的组合悬挂在树栖支撑物下方，它们的四肢有长而弯曲的指骨。在陆地物种中，趾行四足动物（例如，papionins）相对于后足（掌骨和跖骨）具有短直的指骨。值得注意的是，即使人类的四肢比例也相似，尽管他们的手和脚执行不同的功能。人类的手和脚相对于四肢来说较短，具有短而强健的后足、短的外侧指骨和相应较长的第一根手指（大脚趾和拇指）。 NSF 的支持将使 Campbell Rolian 能够测试单鼻动物手脚之间的这些骨骼相似性是否是选择相似功能的结果，或者诸如多效性（当一个基因位点影响表型的多个方面）等潜在发育现象是否导致手脚骨骼彼此之间的相关性比骨骼其他部分之间的相关性更强。手足发育遗传程序之间的多效性可能在手指形态的进化中具有潜在的冲突作用。当手和脚的手指进化到执行类似的运动功能时，多效性应该促进形态的相关变化。然而，当手和脚的数字进化为执行单独的功能时，多效性效应可能会限制手和脚数字形状的独立进化。坎贝尔将从 13 个类群的 500 多个个体的手脚骨骼中收集形态测量数据，这些数据被选择来代表单鼻动物运动行为的多样性和进化相关性的广度。这些数据将用于比较物种内部和物种之间的表型共变模式，检验关于功能与发育在驱动灵长类动物手指形态独立进化方面的重要性的假设。意义和更广泛的影响：很少有研究从经验上解决了发育限制如何使自然选择对形态差异产生偏见。坎贝尔将通过研究哈普罗莱因手和脚的协变来解决这个重要问题。该项目以灵长类肢体骨骼为案例研究，将为脊椎动物形态进化的模式和过程提供更广泛的见解，特别是因为它们与不断发展的进化发育生物学（evo-devo）领域相关。该项目对于人类进化的研究也具有重要意义。例如，结果可能提供证据表明人类的手和脚并没有独立进化其内在比例。这些信息对于检验关于古人类谱系中操纵能力和两足行走的选择性历史的长期假设至关重要。该研究的其他更广泛的影响包括为本科教育提供教学工具，以及创建有价值的灵长类手足骨骼数字档案。通过在同行评审期刊上发表文章和在跨学科会议上发表演讲，该项目还将有助于将体质人类学与进化发育生物学的研究生培训和研究结合起来。