Combing Paleontology and Developmental Biology to Understand Skull Evolution in Turtles

结合古生物学和发育生物学来了解海龟的头骨进化

• 批准号: 415747545
• 负责人: Dr. Ingmar Werneburg
• 金额: --
• 依托单位: The University of Tokyo
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/415747545?language=en
• 关键词: Combing; Paleontology; Developmental; Biology; Understand

The skulls of land vertebrates are characterized by a large diversity. Particularly the region behind the eye, the temporal region, shows considerable differences between major groups, such as mammals, lizards, birds, crocodiles, and frogs. The origin of this diversity - including diverse skull openings and marginal bone reductions - is rarely understood. Of particular interest are turtles that do not resample the skull shape of any living land vertebrate, although they were recently hypothesized to be closely related to extant reptilian groups.In order to understand the temporal skull region and the origin of turtles, a morphogenetic approach to study paleontological and developmental integrity is proposed.Primarily, the anatomy of the temporal region will be coded in a cladistic sense to reconstruct the evolution of this region. Therefore, fossil as well as embryological data will be observed. Geometric morphometric changes in evolution and development of the bones will be analyzed quantitatively to illustrate the pathways leading to either one morphotype and to infer phylogenetic and functional correlations.Micro-computed tomography and histological techniques will be applied to characterize the progress of bone development. Gene expression will be analyzed to illustrate embryonic skull anatomy before the bones begin to form.From a developmental perspective, shared ancestral and derived features will be detected that lead to either one morphotype. By studying fossil groups, which had an even larger diversity of the temporal region than extant groups do, detailed scenarios for the evolutionary changes will be detected. By characterizing the turtle morphotype, a precise phylogenetic conclusion will be drawn for the phylogenetic position of this group that has important impact to understand land vertebrate phylogeny as a whole. Moreover, the integration of genetic and bone development will allow a complex insight to head development in general. In this context, embryological malformations - as seen in humans - will be interpretable from a developmental perspective and their meaning for evolutionary changes will be derived.

陆地脊椎动物的头骨具有多样性大的特点。特别是眼睛后面的区域，即颞区，在哺乳动物、蜥蜴、鸟类、鳄鱼和青蛙等主要物种之间显示出相当大的差异。这种多样性的起源-包括不同的颅骨开口和边缘骨减少-很少被理解。特别令人感兴趣的是乌龟，它们不会对任何活着的陆地脊椎动物的头骨形状进行重新采样，尽管最近有人假设它们与现存的爬行动物群体密切相关。为了了解龟的颞骨区和起源，提出了一种形态发生学方法来研究龟的古生物学和发育完整性。首先，解剖的颞区将编码在一个分支的意义上重建该地区的演变。因此，化石和胚胎学数据将被观察。几何形态的变化在骨骼的进化和发展将定量分析，以说明导致任何一种形态的途径，并推断系统发育和功能的相关性。显微计算机断层扫描和组织学技术将用于表征骨发育的进展。基因表达将被分析，以说明在骨骼开始形成之前的胚胎颅骨解剖。从发育的角度来看，共同的祖先和衍生特征将被发现导致任何一种形态。通过研究化石种群，它们在时间区域的多样性甚至比现存种群更大，进化变化的详细情景将被探测到。通过对龟类形态的刻画，可以得出龟类系统发育位置的精确结论，对了解陆生脊椎动物的整体系统发育具有重要意义。此外，遗传和骨骼发育的整合将使人们对头部发育有一个复杂的了解。在这种情况下，胚胎畸形-正如在人类中看到的-将从发育的角度来解释，它们对进化变化的意义将被推导出来。