Evolution of a Species Complex During Faunal Turnover: Morphometric Analyses of the Montastraea Annularis Reef Coral Complex

9725273巴德超过60%的现代加勒比海珊瑚礁动物群出现在4-1.5 Ma之间的一段动物群更替加速的时期，这是美国国家科学基金会以前资助的研究的一部分。拟议的研究从对这一事件的广泛分类描述转向对其一些最重要参与者的深入分析，并将重点放在Montastraea一个支系的形态进化上。在过去的30年里，选定的支系在生态上一直处于优势地位，至少由10个物种组成。其中包括现代Montastraea Cirularis物种复合体的成员，该物种复合体早期出现在更替阶段，已被广泛用作海洋生态学和地质学的模式生物；例如，用于研究珊瑚搁浅和古气候变化。长期以来，这种复合体一直被认为代表着一个物种，其群体形态因珊瑚礁不同深度的光线而有很大差异。然而，Knowlton&Amp；的同事最近利用生殖和分子数据以及对种群形态的实地研究提出，环纹夜蛾实际上是至少由3个物种组成的复合体。Knowlton的初步研究表明，尽管这三个物种在传统形态特征上存在重叠，但在非传统特征的形态计量分析中，它们明显不同，包括：(1)钙质表面的隔膜三维浮雕；(2)珊瑚石壁的二维结构。此外，从3D形态测量结果推断的进化关系与基于DNA的进化关系一致。这些发现表明，动物群更替的进化研究可能会因为传统程序的不足而受到影响，无法一致地识别不同的遗传物种。因此，拟议的研究将开发更精细的形态计量学方法，以识别化石记录中的物种，并追踪它们在地质时间中的演变。它涉及：(1)使用三维形态计量学对形态特征进行调查，以确定哪些特征与Knowlton&amp；同事正在进行的DNA工作的结果最匹配；(2)基于上述特征的子集设计一种程序，可用于识别化石材料中的物种并通过地质时代追踪它们；(3)通过分散的地理位置上的一系列晚更新世珊瑚礁阶地，每隔100 Kyr检查这些物种的形态稳定性；(4)使用形态计量学和系统发育学相结合的方法重建该支系的系统发育。在前两组分析中，我将与南希·诺尔顿合作，在第三组中，我将与约翰·潘多尔菲合作。除了实地和运输费用，Knowlton&Amp；Pandolfi由史密森学会单独提供资金。这些材料将包括具有遗传特征的殖民地(由Knowlton提供)；新收集的具有生态特征的晚更新世殖民地(由Pandolfi收集)；以及博物馆收藏的年代良好的渐新世至早更新世，其中大部分是我早期NSF资助工作的一部分。研究结果将被用于：(1)记录环斑潜蝇复合体内物种形成和灭绝事件的时间和模式，并将它们与总的动物群周转模式联系起来；(2)检查分支内不同级别的形态演变趋势，并解释其原因。因此，它们将为评估外部环境因素和生物相互作用在造成营业额方面的作用提供宝贵的信息。拟议的研究将提供一个优雅的模型系统，将分子、生殖、形态和化石数据整合到一个在生态上重要但可管理的规模分支中。这将是珊瑚礁中第一个将化石数据整合在一起并用于推断进化过程的系统。除了古生物学，拟议的研究还将在珊瑚礁生物学、系统学和分子进化方面做出重要贡献。对这些物种过去生态作用的评估将有助于对现代分布的解释，将开发新的形态技术来可靠地分离密切相关的物种，化石和分子数据的结合将在珊瑚中提供相对最近分化的类群的分子进化速度的第一次估计。请拨经费用于图像分析设备；研究生的工资；野外工作收集晚更新世殖民地；以及使用大学扫描电子显微镜和共焦显微镜。

9725273 Budd More than 60% of the modern Caribbean reef coral fauna arose between 4-1.5 Ma during an episode of accelerated faunal turnover, documented as part of previous NSF funded research. The proposed research shifts from a taxonomically broad characterization of this episode to an in-depth analysis of some of its most important participants, and focuses on morphologic evolution within a clade of Montastraea. The selected clade has been ecologically dominant for the past 30 myr and consists of at least 10 species. Among them are members of the modern Montastraea annularis species complex, which arose early during the turnover episode and have widely been used as a model organism in marine ecology and geology; e.g., to study coral beaching and paleoclimatic change. The complex has long been thought to represent one species, whose colony morphology varied extensively in response to light at different reef depths. However, Knowlton & co-workers have recently used reproductive and molecular data and field studies of colony morphology to propose that M. 'annularis' is actually a complex of at least 3 species. A pilot study with Knowlton has shown that, although the 3 species overlap in traditional morphologic characters, they are clearly distinct in morphometric analyses of non-traditional characters including: (1) the 3D relief of septa on calical surfaces and (2) the 2D structure of the corallite walls. Moreover, evolutionary relationships inferred from 3D morphometric results correspond with those based on DNA. These findings suggest that the evolutionary study of faunal turnover may be compromised by the inadequacy of traditional procedures to consistently recognize genetically distinct species. The proposed research will therefore develop more refined morphometric methods for recognizing species in the fossil record and tracing their evolution through geologic time. It involves: (1) conducting a survey of morphologic characters using 3D morphometrics to determine which char acters best match the results of ongoing DNA work by Knowlton & co-workers; (2) devising a procedure based on a subset of the characters above, which can be used to recognize species in fossil material and trace them through geologic time; (3) examining the morphologic stability of these species at intervals of 100 kyr through series of Late Pleistocene reef terraces at scattered geographic locations; (4) Reconstructing the phylogeny of the clade using combined morphometrics & phylogenetic approaches. In the first 2 sets of analyses, I will collaborate with Nancy Knowlton, and in the third, with John Pandolfi. Except for field and shipping expenses, Knowlton & Pandolfi are funded separately by the Smithsonian Institution. The material will consist of genetically characterized colonies (provided by Knowlton); newly collected, ecologically characterized Late Pleistocene colonies (collected with Pandolfi); and well-dated Oligocene to Early Pleistocene in museum collections, most of which I made as part of earlier NSF funded work. The results will be used: (1) to document the timing and pattern of speciation and extinction events within the M. annularis complex, and relate them to patterns of overall faunal turnover, and (2) to examine trends of morphologic evolution at various levels within the clade and interpret their cause. They will thus contribute valuable information for assessing the roles of external environmental factors and biological interactions in causing turnover. The proposed research will provide an elegant model system, integrating molecular, reproductive, morphologic, and fossil data in an ecologically important but manageable size clade. It will be the first such system in reef corals to incorporate fossil data and use them for inferring evolutionary processes. In addition to paleontology, the proposed research will contribute in important ways to coral reef biology, systematics, and molecular evolution. Interpretation of modern distributions will be aided by eval uation of the past ecological roles of these species, new morphological techniques for reliably separating closely related species will be developed, and the combination of fossil and molecular data will provide the first estimates in corals for rates of molecular evolution for relatively recently diverged taxa. Funds are requested for image analysis equipment; salary for a grad student R.A. & the PI; field work collecting Late Pleistocene colonies; and the use of university SEM & confocal microscopes.