The Interference Avoidance Hypothesis and Scaling Principles in Crinoids

海百合的干扰避免假说和缩放原理

• 批准号: 9706071
• 负责人: Tomasz Baumiller
• 金额: $ 7.09万
• 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: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706071&HistoricalAwards=false
• 关键词: Interference; Avoidance; Hypothesis; Scaling; Principles

9706071 Baumiller Crinoids were an important component of ancient marine environments and an excellent record of their diverse morphologies has been preserved, as is demonstrated by over 900 described genera. Yet 'm spite of their importance and diversity, our interpretations of their evolutionary history and paleoecology are limited and many questions remain unanswered. Two problems will be tackled in this study: I)are the predictions implicit 'm the tiering model (Ausich, 1980) supported by the pattern of spatial distribution of individuals of the same species? And 2) what structural or functional rules govern the growth of stalked crinoids? To tackle the first problem, one prediction implicit in the tiering model (Ausich, 1980), namely that the same-tier, upstream neighbors of crinoids interfere with feeding and that interferences should be avoided, will be tested by quantifying the patterns of spatial distribution of a living isocrinid, Neocrinus decorus. The patterns will be quantified by digitizing photos taken from a submersible.A first-order prediction states that if resources are limiting, since individuals of the same species utilize the same resources upstream neighbors should be avoided or should lie beyond some critical distance. Manipulations of in situ specimens and specimens 'm a flow tank will be used to further assess whether crinoids actively avoid interference. Another test of this hypothesis will involve collecting several 'individuals of N. decorus by submersible, tagging and redeploying them onto a small area, and episodically monitoring their pattern of distribution; a non-random pattern would support the hypothesis. A paleontological prediction of the intraspecific avoidance hypothesis is that the spatial patterns of distribution characterizing avoidance should be expressed only among taxa capable of relocation (e.g.: advanced cladids, articulates), but not among those taxa permanently attached to the substrate. Tests of this prediction will involve obt aining data on the spatial distribution of complete individuals of the same species from a single bedding plane of a burial horizon (e.g.: LeGrand, Burlington, Crawfordsville) and determining whether the pattern differs from random and is consistent with the hypothesis of avoidance. Results of all these approaches will provide a basis for assessing the relative importance of factors such as hydrodynamic regime and nutrient limitations to crinoid autecology and, possibly, evolutionary history. To determine if structural or functional rules govern crinoid morphology , stalk length and diameter and arm length will be measured for fossil taxa and for extant crinolds collected by submersible. Comparison of these data to predictions based on three scaling models, geometric, stress, and elastic, will be used to determine if the observed data support any of the models. Stalked crinoid-. which are rheophiles utilize a feeding posture which requires a certain flexure of the stalk, and these crinolds are predicted to scale according to the model of elastic similarity. If that prediction is home out for such crinoids, i.e., those with "standard" ecologies (rheophiles utilizing a Parabolic Filtration Fan Posture), fossil taxa thought to have had unusual ecologies (calceocrinids, Seirocrinus, Pentacrinus) will be examined to determine if they scaled according to rules different from elastic similarity. A successful completion of the project will solve some major problems of crinoid functional morphology and test an important ecological and paleoecological model, that of tiering. Although crinoids are the focus here, the methods developed have broader implications. For example, the principles governing crinoid morphology should also govern the growth of other aquatic rheophiles.

小行星9706071 海百合是古代海洋环境的重要组成部分，其多样的形态已被保存下来，超过900个描述的属证明了这一点。 然而，尽管它们的重要性和多样性，我们对它们的进化历史和古生态学的解释是有限的，许多问题仍然没有答案。 本研究将解决两个问题：（1）层次模型（Ausich，1980）中隐含的预测是否得到同一物种个体空间分布模式的支持？ 2）有柄海百合的生长受到什么样的结构或功能规则的支配？ 为了解决第一个问题，一个预测隐含在分层模型（Ausich，1980年），即同层，海百合的上游邻居干扰进食和干扰应该避免，将通过量化的空间分布模式的生活isocrinid，新海百合decorus进行测试。 这些模式将通过数字化从潜水器拍摄的照片来量化。一阶预测指出，如果资源有限，由于同一物种的个体利用相同的资源，上游邻居应该避免或应该位于一些临界距离之外。 对原位标本和流动槽中标本的操作将用于进一步评估海百合是否主动避免干扰。 对这一假设的另一个检验将涉及收集N.通过使用潜水器，标记并将其重新部署到一个小区域，并定期监测其分布模式;非随机模式将支持这一假设。 种内回避假说的一个古生物学预测是，回避的空间分布模式应该只在能够重新定位的类群中表达（例如：先进的分支，有节），但不属于那些类群永久附着到基板。 这种预测的检验将涉及从埋藏层位的单一层面获得关于同一物种的完整个体的空间分布的数据（例如：LeGrand，Burlington，克劳福兹维尔），并确定该模式是否不同于随机，是否与回避假设一致。 所有这些方法的结果将提供一个基础，评估的相对重要性的因素，如流体动力学制度和营养限制海百合的autecology，并可能，进化史。 为了确定海百合的形态、茎的长度和直径， 将测量潜水器收集的化石分类群和现存的海百合的臂长。 比较 这些数据的预测基于三个缩放模型，几何，应力和弹性，将被用来 确定观察到的数据是否支持任何模型。 有柄海百合。它们是嗜流生物，利用需要一定弯曲的茎的进食姿势，并且这些卷缩物被预测成比例。 根据弹性相似模型， 如果这一预测是这样的海百合，即，那些具有“标准”生态的（利用抛物线过滤扇波的流栖生物），被认为具有不寻常生态的化石分类群（钙海百合，Seirocrinus，Pentacrinus）将被检查，以确定它们是否缩放 根据不同于弹性相似性的规则， 该项目的成功完成将解决海百合功能形态学的一些主要问题，并测试一个重要的生态和古生态模式，即分层。 虽然海百合是这里的重点，但开发的方法具有更广泛的意义。 例如，海百合形态的原则也应该支配其他水生喜流生物的生长。