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

小行星9725273 超过60%的现代加勒比海珊瑚礁珊瑚动物群出现在4 - 1.5马之间的一个插曲，动物群的加速营业额，记录为以前的NSF资助的研究的一部分。 拟议的研究从分类广泛的表征这一事件的深入分析，其最重要的参与者，并专注于Montastraea的一个分支内的形态进化。 所选的分支已经在过去的30万年的生态优势，并由至少10个物种。 其中包括现代Montastraea annularis物种复合体的成员，它们出现在更替阶段的早期，并被广泛用作海洋生态学和地质学的模式生物;例如，研究珊瑚搁浅和古气候变化。 长期以来，该复合体被认为代表一个物种，其群体形态在不同的珊瑚礁深度对光线的反应中变化很大。 然而，诺尔顿的同事最近利用生殖和分子数据以及对菌落形态的实地研究提出，M.& "annularis"实际上是一个至少有3个物种的复合体。 与诺尔顿的初步研究表明，虽然3种珊瑚在传统形态特征上重叠，但它们在非传统特征的形态测量分析中有明显的区别，包括：（1）杯状表面上隔膜的三维浮雕和（2）珊瑚壁的二维结构。 此外，从3D形态测量结果推断的进化关系与基于DNA的进化关系相一致。 这些研究结果表明，动物区系营业额的进化研究可能会受到传统程序的不足，一贯承认遗传上不同的物种。 因此，拟议中的研究将开发出更精确的形态测量方法，用于识别化石记录中的物种，并追踪它们在地质时期的进化。 它涉及：（1）使用三维形态测量学对形态特征进行调查，以确定哪些特征最符合诺尔顿同事正在进行的DNA工作的结果;（2）基于上述特征的子集设计一个程序，该程序可用于识别化石材料中的物种，并通过地质时间追踪它们;&（3）通过在分散的地理位置上的一系列晚更新世礁阶地，以10万年的间隔检查这些物种的形态稳定性：（4）使用组合的形态测量学系统发育方法重建分支的进化史。& 在前两组分析中，我将与Nancy诺尔顿合作，在第三组分析中，我将与John Pandolfi合作。 除了现场和运输费用，诺尔顿潘多尔菲是由史密森学会单独资助。& 这些材料将包括遗传特征的殖民地（由诺尔顿提供）;新收集的，生态特征的晚更新世殖民地（与潘多尔菲收集）;以及博物馆收藏的日期明确的渐新世至早更新世，其中大部分是我作为早期NSF资助工作的一部分。 研究结果将用于：（1）记录物种形成和灭绝事件的时间和模式。annularis复合体，并将它们与整体动物区系更替模式联系起来;（2）检查分支内不同层次的形态进化趋势并解释其原因。 因此，它们将为评估外部环境因素和生物相互作用在造成周转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，整合分子，生殖，形态和化石数据在生态上重要的，但可管理的大小分支。 这将是第一个这样的系统在礁珊瑚纳入化石数据，并利用它们来推断进化过程。 除了古生物学，拟议中的研究将在重要方面对珊瑚礁生物学，系统学和分子进化做出贡献。 现代分布的解释将有助于评估这些物种过去的生态作用，新的形态学技术，可靠地分离密切相关的物种将被开发，化石和分子数据的结合将提供第一次估计珊瑚的分子进化速度相对较近的分歧类群。 要求提供资金用于图像分析设备;一名研究生的薪金。Π收集晚更新世殖民地的实地工作;以及使用大学SEM共聚焦显微镜。&

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.