Dissertation Research: The Macroevolutionary Consequences of a Neogastropod Adaptation

论文研究：新腹足动物适应的宏观进化后果

• 批准号: 0073248
• 负责人: David Jablonski
• 金额: $ 1万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2003-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073248&HistoricalAwards=false
• 关键词: Dissertation; Research; Macroevolutionary; Consequences; Neogastropod

0073248Jablonski and PriceAlthough evolutionary biologists have formalized the study of adaptation, few studies explain both why a trait is adaptive and ho--w it affects a lineage's history. Graduate student Rebecca Price, assisted by her adviser Dr. David Jablonski, addresses this issue in a study of fossil and living species of a group of gastropod molluscs of the Fasciolariidae. The neogastropods are an ideal focal taxon because they have high modern diversity, permitting the use of living animals to determine the functional significance of the character in question, and a rich fossil record directly to observe morphological changes through geologic time. The hypotheses under test concern the columellar folds, or plications on a gastropod shell's aperture, that traditionally are used as taxonomic characters, and that may function as adaptations, for example in body retraction to avoid predators, or in muscle attachment to increase speed of movement. Such functional adaptations may have affected rates and patterns of species diversification in different sublineages within the Fasciolariidae (Neogastropoda: Mollusca). This family has a rich fossil record, a range of fold morphologies, and, according to a preliminary phylogeny, has lost and added folds repeatedly. The student will use computed tomography (facilities made available at Argonne National Laboratory outside Chicago) to depict in 3-dimensions and quantify a series of characters that describe columellar fold morphology in ca. 100 samples in this family. To test that columellar folds are adaptive, and to evaluate some hypothetical functions, the student will (1) map each aspect of fold morphology onto an evolutionary tree to determine when it evolved, and (2) conduct a series of functional experiments at a marine station on shells with and without folds. The experiments are designed to improve our understanding of correlations between morphology and function, with the results extrapolated back on the phylogeny to track the 130 million years of fasciolariid history in functional terms.

0073248Jablonski 和 Price 尽管进化生物学家已经正式研究了适应性，但很少有研究能够解释为什么特征具有适应性以及它如何影响谱系的历史。 研究生丽贝卡·普莱斯（Rebecca Price）在导师大卫·贾布隆斯基（David Jablonski）博士的协助下，在对一组腹足类软体动物的化石和现存物种的研究中解决了这个问题。新腹足类动物是理想的焦点分类单元，因为它们具有高度的现代多样性，允许使用活体动物来确定相关特征的功能意义，并且拥有丰富的化石记录，可以直接观察地质时期的形态变化。 所测试的假设涉及腹足动物壳孔上的小柱褶皱或褶皱，传统上将其用作分类特征，并且可能起到适应作用，例如在身体收缩中以避免捕食者，或在肌肉附着中提高运动速度。这种功能性适应可能影响了片吸虫科（新腹足纲：软体动物）不同亚系的物种多样化的速度和模式。 该科拥有丰富的化石记录、一系列的褶皱形态，并且根据初步的系统发育，褶皱不断丢失和增加。 学生将使用计算机断层扫描（芝加哥郊外的阿贡国家实验室提供的设施）以 3 维方式描绘并量化一系列特征，这些特征描述了大约 3 小时内的小柱褶皱形态。该家族有 100 个样本。 为了测试柱状褶皱的适应性，并评估一些假设的功能，学生将 (1) 将褶皱形态的各个方面映射到进化树上，以确定它何时进化，以及 (2) 在海洋生物中进行一系列功能实验站在有或没有褶皱的贝壳上。 这些实验旨在提高我们对形态和功能之间相关性的理解，并将结果外推至系统发育史，从功能角度追踪片形虫科 1.3 亿年的历史。