DISSERTATION RESEARCH: The species versus subspecies conundrum: quantitative assessment from integrating multiple data types under a single Bayesian framework in Hercules beetles

论文研究：物种与亚种难题：在大力神甲虫的单一贝叶斯框架下整合多种数据类型的定量评估

• 批准号: 1501462
• 负责人: L. Lacey Knowles
• 金额: $ 2.02万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501462&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; species; versus; subspecies

Are there differences in how species and subspecies are designated among different groups of organisms? If so, surveys of biodiversity could be biased, potentially either under- or over-estimating levels of species diversity. Researchers will address this issue using genetic and morphological data from two groups of Hercules beetles (genus Dynastes), where diversity patterns differ between North and South America, perhaps because of differing applications of species versus subspecies designations. Through quantitative assessments of the observed differences among taxa, researchers will test if genetic and morphological differences between species are more pronounced than those found among subspecies. Knowledge gained by this research will demonstrate how taxonomy can be assessed consistently, objectively, and quantitatively across distinct groups of organisms and between geographic regions. Such a standardized approach is critical to avoiding potential biases in biodiversity surveys of species diversity and the identification of taxa in need of conservation. One graduate student will be trained in diverse systematic methods and a website will be established to broadly disseminate the species delimitation methods developed by the researchers.While considerable recent research has focused on quantitative methods for objectively delimiting species, an overlooked, but equally important, issue regards the nature of the taxonomic entities being delimited. A model-based approach will be applied to test whether species and subspecies of Hercules beetles are statistically equivalent. Researchers will also test if currently recognized taxa represent different points along the speciation continuum and whether levels of differentiation fit with expectations based on the time taxa have been diverging. Because both phenotypic and genetic data will be analyzed in a Bayesian framework, the research will be able to determine whether disagreements in species boundaries among data types reflect (i) discordance with the actual history of lineage splitting, or (ii) differences in the amount of time required for differentiation to become apparent among the taxa in different data types (specifically, different rates of evolutionary change in genetic versus morphological data). This work advances biodiversity studies by making it possible for the theoretical view of speciation as a continuous process to be applied in practice in a quantitative manner such that the taxonomic equivalent units of biodiversity can be determined for comparisons of species diversity in different geographic regions and across different groups of organisms.

在不同的生物群体中，物种和亚种的命名方式有什么不同吗？如果是这样的话，对生物多样性的调查可能是有偏见的，可能会低估或高估物种多样性的水平。研究人员将利用两组大力神甲虫（大力神甲虫属）的遗传和形态学数据来解决这个问题，这两组大力神甲虫的多样性模式在北美和南美之间存在差异，可能是因为不同的物种和亚种命名的应用。通过对观察到的分类群之间的差异进行定量评估，研究人员将测试物种之间的遗传和形态差异是否比亚种之间的差异更明显。从这项研究中获得的知识将展示如何在不同的生物群体和不同的地理区域之间一致、客观和定量地评估分类学。这种标准化方法对于避免物种多样性调查和需要保护的分类群的潜在偏差至关重要。一名研究生将接受各种系统方法的培训，并建立一个网站，广泛传播研究人员开发的物种划界方法。虽然最近大量的研究集中在客观划分物种的定量方法上，但一个被忽视但同样重要的问题是被划分的分类实体的性质。一种基于模型的方法将被应用于测试大力神甲虫的物种和亚种在统计上是否相等。研究人员还将测试目前公认的分类群是否代表了物种形成连续体的不同点，以及分化水平是否符合基于分类群分化时间的预期。由于表型和遗传数据都将在贝叶斯框架中进行分析，因此研究将能够确定数据类型之间物种边界的差异是否反映了(i)与谱系分裂实际历史的不一致，或者（ii）不同数据类型的分类群之间分化所需时间的差异（具体而言，遗传数据与形态数据的进化变化率不同）。这项工作推动了生物多样性的研究，使物种形成作为一个连续过程的理论观点能够以定量的方式应用于实践，从而可以确定生物多样性的分类等效单位，用于比较不同地理区域和不同生物群体的物种多样性。