Research Starter Grant: Investigation of the presumed correspondence between morphological and genetic distance in human populations

摘要本项目以方法学为重点，并提出以下问题：中性基因位点与形态表型性状之间的对应关系（如果有的话）的本质是什么？通过提出这个问题，该项目的最终目标是重新评估生物人类学中评估人口关系（相似/不相似程度）背后的假设和方法。传统上，生物人类学家依靠颅骨的表型（形态）特征分析来评估种群关系，假设形态特征和遗传关系之间存在一对一的对应关系。尽管生物人类学家一直都明白，可能存在违反这一假设的情况，并且可能会影响我们充分描述种群关系的能力，但直到最近，他们既没有技术也没有方法来严格检验这种假定的对应关系。该建议利用三维形态计量学和古代DNA分析的新方法工具来测试这一基本假设的有效性。该项目提出了两个相关的问题：(1)现代人类种群中骨骼形态和遗传距离之间的关系本质是什么？(2)哪种形态特征（如果有的话）提供了最多的遗传信息？基因分析将在田纳西大学诺克斯维尔分校（UTK）的分子人类学实验室（现代和古代DNA）进行，而形态分析将在乔治·米尔纳博士领导的宾夕法尼亚州立大学生物考古实验室进行。本研究将探讨人类颅齿形态与遗传距离之间关系的本质。它还将解决遗传距离是否似乎是形态距离的主要决定因素的问题，或者是否援引外部影响形态的其他解释可能更有可能。最后，该研究将确定在人口关系研究中最有用的潜在颅齿数据子集，并可用于未来的人口距离研究。更广泛的影响形态和遗传数据之间的一致性程度是生物学家和遗传学家长期争论的一个广泛的分类群问题。环境和遗传变量在多大程度上可以解释形态，这与许多不同物种的进化和解剖研究有关。在人类中发现的形态学和遗传距离之间的不一致表明形态学和遗传学的复杂关系使得从形态学确定遗传关系变得困难。这也将提出一些有趣的问题，关于遗传、形态和环境相互作用的本质，这些问题将在未来的研究中得到回答。

Graciela S. CabanaMinority Postdoctoral Fellowship Starter Grant AbstractThis proposed project is methodological in focus and asks: what is the nature of correspondence, if any, between neutral genetic loci and morphological phenotypic traits? By asking this question, the project's ultimate goal is to re-evaluate assumptions and methods behind assessing population relationships (degree of similarity /dissimilarity) in biological anthropology.Traditionally, bioanthropologists have relied on phenotypic (morphological) trait analyses of the crania to assess population relationships, assuming that a one-to-one correspondence exists between morphological traits and genetic relationships. Although bioanthropologists have always understood that violations of this assumption probably exist, and could potentially impinge on our ability to adequately characterize population relationships, they had access neither to the technology nor the methods to rigorously test this presumed correspondence, until very recently.This proposal takes advantage of the new methodological tools of 3D morphometrics and ancient DNA analyses to test the validity of this fundamental assumption.The proposed project asks two related questions:(1) What is the nature of the relationship between skeletal morphology and genetic distance in modern human populations?(2) Which morphological traits if any, provide the most genetic information?Genetic analyses will be carried out at the Molecular Anthropology laboratories (modern and ancient DNA) at the University of Tennessee, Knoxville (UTK), while morphological analyses will take place at the Bioarchaeology Laboratory at Penn State, headed by Dr. George Milner.Intellectual MeritThe proposed study will investigate the nature of the relationship between human craniodental morphology and genetic distance. It will also address the question of whether genetic distance appears to be the primary determinant of morphological distance, or whether alternative explanations invoking external influences on morphology may be more likely. Finally, the study will identify potential subsets of craniodental data that are most useful in studies of human population relationships, and that can be used in future studies of human population distances.Broader ImpactThe degree of concordance between morphological and genetic data has been a longstanding issue of debate among biologists and geneticists for a wide range of taxa. The extent to which environmental and genetic variables can explain morphology is relevant to research regarding the evolution and anatomy of many different species. Non-congruence between morphology and genetic distances discovered among humans would indicate that the complex relationship of morphology and genetics makes determining genetic relationships from morphology difficult. It would also raise interesting questions about the nature of the interaction of genetics, morphology and the environment to be answered in future studies.