Palaeo-Evo-Devo of Insecta – the amber forest as a major source of information for reconstructing the evolutionary history of an ecologically important group

昆虫纲的古-进化-进化——琥珀森林是重建生态重要群体进化史的主要信息来源

• 批准号: 446411314
• 负责人: Professor Dr. Joachim Tobias Haug
• 金额: --
• 依托单位: Arbeitsgruppe Zoomorphologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/446411314?language=en
• 关键词: Palaeo; Evo; Devo; Insecta; amber

Insecta is one of the dominating animal groups today, in terrestrial as well as in freshwater ecosystems. However, insect diversity is currently endangered as different studies have shown. To enhance our understanding on the processes leading to the diversity loss, similar processes in past ecosystems can provide crucial information. Such information can be retrieved from the fossil record. In the focus of this project are insects preserved in amber. Amber can preserve morphological structures to a very high degree of detail, comparable to that in insects living today. Yet, the diversity of Insecta is not only represented by its large species richness, but especially by its morphological diversity. This becomes very apparent when not only adult forms, but also earlier developmental stages are included into the analyses, such as larvae, nymphs, or similar immature stages. The inclusion of such developmental stages into analyses is not restricted to insects living today, but is possible with fossil representatives as well. In this way, evolutionary changes in the individual development (ontogeny) of different insects can be investigated (palaeo-evo-devo). Especially in amber, many earlier developmental stages in very good preservation can be found which allow such investigations. With this material, different aspects of fossil developmental biology can be studied in the frame of this project, e.g., when was the oldest appearance of certain developmental stages, or which types of immatures were preserved in amber that are now extinct, possessing a mixture of morphological characters of known modern types, or possessing a morphology completely unknown from modern types. For these investigations, developmental stages of insects in amber of different ages are available, i.e. from 100 million-year-old, 40–50 million-year-old and about 25 million-year-old amber, as well as modern representatives from diverse museum collections. The material is documented under high resolution with different light microscopic methods as well as micro-computed tomography (microCT) to retrieve all morphological details, detect unusual character combinations, and identify possible developmental sequences. As it will in most cases not be possible to identify that different developmental stages belong to the same species, a relaxed taxonomic frame will be used; in this way, developmental sequences within larger phylogenetic groups can be identified. By comparing data from different geological ages, evolutionary changes of the developmental pattern can be detected. These can be the basis for a better understanding of diversification and extinction events in insects.

昆虫是当今陆地和淡水生态系统中的主要动物类群之一。然而，不同的研究表明，昆虫多样性目前正处于濒危状态。为了加强我们对导致多样性丧失的过程的理解，过去生态系统中的类似过程可以提供关键信息。这些信息可以从化石记录中找到。这个项目的重点是保存在琥珀中的昆虫。琥珀可以保存形态结构到非常高的细节程度，与今天生活的昆虫相当。然而，昆虫门的多样性不仅表现在其丰富的物种，但特别是其形态的多样性。当不仅将成虫形式，而且将早期发育阶段（例如幼虫、若虫或类似的未成熟阶段）纳入分析时，这一点变得非常明显。将这些发育阶段纳入分析并不局限于今天生活的昆虫，但也有可能与化石代表。通过这种方式，可以研究不同昆虫个体发育（个体发育）中的进化变化（古-进化-进化）。特别是在琥珀中，可以发现许多保存良好的早期发育阶段，这使得这种研究成为可能。有了这些材料，可以在这个项目的框架内研究化石发育生物学的不同方面，例如，某些发育阶段的最古老的外观是什么时候，或者哪种类型的未成熟体被保存在琥珀中，现在已经灭绝，具有已知现代类型的形态特征的混合物，或者具有完全不为现代类型所知的形态。在这些研究中，可获得不同年龄琥珀中昆虫的发育阶段，即1亿年、4000 - 5000万年和约2500万年的琥珀，以及来自不同博物馆收藏的现代代表。该材料在高分辨率下用不同的光学显微镜方法以及微型计算机断层扫描（microCT）记录，以检索所有形态学细节，检测不寻常的字符组合，并确定可能的发育序列。由于在大多数情况下不可能确定不同发育阶段属于同一物种，因此将使用宽松的分类框架;通过这种方式，可以确定较大系统发育组内的发育序列。通过对不同地质时代资料的对比，可以发现发育模式的演化变化。这些可以成为更好地了解昆虫多样性和灭绝事件的基础。