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The great mammalian evolutionary transitions -Insights from bone micro-anatomy

哺乳动物的伟大进化转变——骨显微解剖学的见解

基本信息

批准号：
388111938
负责人：
Dr. Eli Amson
金额：
--
依托单位：
Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung (MfN)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/388111938?language=en
关键词：
great mammalian evolutionary transitions Insights

项目摘要

Starting with a terrestrial ancestral state, mammalian evolution is characterized by major transitions involving diverse lifestyles. Numerous aerial, aquatic, and subterranean adaptations were convergently acquired several times throughout the mammalian clade. As extinct taxa document evolutionary acquisitions that are not represented today, it is crucial to include data from both recent and fossil specimens in comparative analyses. Regarding traits related to lifestyle, fossils mostly preserve osteological features. Furthermore, the inner structure of the skeleton is particularly marked by functional adaptations and comparable over a broad taxonomic scale. I will therefore study the impact of lifestyle on mammalian bone micro-anatomy using two-dimensional (2D) and three-dimensional (3D) approaches. While 2D micro-anatomical features (such as bone compactness) related to aquatic adaptations are well investigated, those that concern aerial and subterranean adaptations are either superficially understood or hitherto unknown. The implications of 3D micro-anatomical features (such as the mean thickness of the trabeculae) on lifestyle are virtually unknown outside primates. A broad micro-anatomical dataset at the scale of mammals will hence be built to encompass their major evolutionary transitions. Consistently found at a non-vestigial state across mammals, the humerus and a lumbar vertebra of each specimen will be scanned using high-resolution computed tomography (µCT). Quantitative 2D and 3D micro-anatomical parameters will be extracted and studied in a phylogenetically informed framework. Firstly, conclusions will be drawn regarding the lifestyle of fossils of particular interest. Secondly, the association between micro-anatomical features and each of the major evolutionary transition types will be addressed, and the ancestral states of major clades will be reconstructed. Finally, the overall dataset will be used to reveal patterns associated with great evolutionary transitions, such as the presence of exaptations (features that were not acquired by natural selection for their current role) and the chronology of morphological and micro-anatomical acquisitions.

从陆地祖先状态开始，哺乳动物进化的特点是涉及不同生活方式的重大转变。许多空中，水生和地下的适应收敛收购几次整个哺乳动物分支。由于灭绝的分类群记录了今天没有代表的进化收购，因此在比较分析中包括最近和化石标本的数据至关重要。关于与生活方式有关的特征，化石大多保留了骨骼学特征。此外，骨骼的内部结构特别具有功能适应性，并且在广泛的分类尺度上具有可比性。因此，我将使用二维（2D）和三维（3D）方法研究生活方式对哺乳动物骨骼显微解剖的影响。虽然2D微观解剖特征（如骨致密性）有关的水生适应性进行了很好的研究，那些关注空中和地下的适应性要么是表面上理解或迄今未知。3D微观解剖特征（如小梁的平均厚度）对生活方式的影响在灵长类动物之外几乎是未知的。因此，将建立一个广泛的哺乳动物规模的微观解剖数据集，以涵盖其主要的进化过渡。对于在哺乳动物中发现的非退化状态的一致性，将使用高分辨率计算机断层扫描（µCT）对每件标本的肱骨和腰椎进行扫描。定量的2D和3D微观解剖参数将被提取，并在遗传学的知情框架研究。首先，将得出关于特别感兴趣的化石的生活方式的结论。其次，显微解剖特征和每一个主要的进化过渡类型之间的关联将得到解决，主要分支的祖先状态将被重建。最后，整个数据集将用于揭示与重大进化转变相关的模式，例如存在外适应（未通过自然选择获得其当前作用的特征）以及形态学和微观解剖学采集的年表。