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Dissertation Research: A Phylogenetic and Morphometric Analysis of Early Palezoic Archaeogastropods: An Examination of the Expansion of a Clade into Morphospace

论文研究：早期古生代古腹足动物的系统发育和形态计量分析：对进化枝向形态空间的扩展的检验

基本信息

批准号：
9213077
负责人：
金额：
$ 0.95万
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：
1992
资助国家：
美国
起止时间：
1992-12-15 至 1995-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9213077&HistoricalAwards=false
关键词：
Dissertation Research Phylogenetic Morphometric Analysis

项目摘要

The Archaeogastropoda appeared in the Late Cambrian and rapidly radiated to encompass a wide range of morphologies. These included most of the morphotypes associated with basic gastropod lifestyles. A minor morphologic radiation occurred later with changes in shell ornamentation. Archaeogastropods thus offer multiple character types and morphologic levels for describing changes through time in the patterns of morphology. This project includes both phylogenetic and morphometric analyses of Early Paleozoic archaeogastropods. These approaches will be used to compare typical morphological distances of differences between sister species in three different morphospaces: 1) one based upon twelve "basic-shell" characters appearing at the group's origin; 2) one based upon shell ornamentation, which did not appear in most subgroups until the Late Ordovician; and 3) one based upon character complexes thought to have a basic functional utility. Using ornamentation to compare the temporal patterns of clade expansion in both "early" and "later" shell characters will provide information on whether inter- and intraclade variation depend more on the time in which the clade radiated (i.e., extrinsic factors) or upon the ages of the character states distinguishing them (i.e., intrinsic factors). Examining phylogenetic patterns in a morphospace of character complexes will describe the archaeogastgropod radiation in a biologically more meaningful manner and also provide an additional morphologic "level" to test for non-random sorting of clades.

古腹足动物出现于寒武纪晚期，并迅速辐射出多种形态。其中包括与基本腹足动物生活方式相关的大多数形态类型。随后随着贝壳装饰的变化，出现了轻微的形态辐射。因此，古腹足动物提供了多种特征类型和形态水平来描述形态模式随时间的变化。该项目包括早期古生代古腹足动物的系统发育和形态测量分析。这些方法将用于比较三个不同形态空间中姐妹物种之间差异的典型形态距离：1）一种基于出现在群体起源处的十二个“基本壳”特征； 2）一种基于贝壳纹饰的，直到晚奥陶世才出现在大多数亚群中； 3）一种基于性格复合体的特征，被认为具有基本的功能实用性。使用装饰来比较“早期”和“晚期”贝壳特征中进化枝扩展的时间模式将提供关于进化枝间和进化枝内变异是否更多地取决于进化枝辐射的时间（即外在因素）或区分它们的特征状态的年龄（即内在因素）的信息。检查特征复合体形态空间中的系统发育模式将以生物学上更有意义的方式描述古腹足动物辐射，并提供额外的形态“水平”来测试进化枝的非随机排序。