Das Füllen einer Lücke: Morphologie der Schwämme im Zeitalter der Phylogenomik
Evolution, Anthropologie
Zusammenfassung der Projektergebnisse
Sponges are arguably the simplest animals, yet they play a crucial role in our understanding of animal evolution. Their lack of many canonical metazoan features places them in a situation where any information about their evolution can inform animal evolution as a whole. In order to fulfill their role, a better understanding of the internal relationships of the four extant sponge classes and their sequence of character acquisition is required. The early fossil record of sponges is rich and diverse, but hard to understand without a richer morphological framework for the phylum. Fossil groups such as reticulosans and protomonaxonids are unlikely to be monophyletic and more work is required to understand their affinities. We described Calliospongia chunchengia, a unique new genus which showcases the complicated nature of the early sponge fossil record. The importance of sponge morphology cannot be overstated and has been the source of one of the biggest debates in the history of zoology. Specifically, the current consensus about sponge relationships is based on molecular analyses, but the relations between calcareans and homoscleromorphs is still unclear due to a lack of morphological synapomorphies, so more detailed studies of morphology open up a possibility to reevaluate them. Several key aspects of sponge morphology had not been fully exploited until now. For example, their spicules, which constitute the mineral component of sponge skeletons, have often been used as discrete characters based on traditional terminology. We attempted to break down each spicule category into more granular characters in order to be able to study their evolution. Characters refer to features such as symmetry, number of rays, mineralogy or texture. These new spicule characters reveal patterns of morphological patterns across the phylum, suggesting alternative results to what the current phylogenomic consensus indicates. Morphology as a whole has a lot of staying power when it comes to, at the very least, understanding the evolutionary sequences of groups and serve as a counterbalance to the exclusively phylogenomic approaches that currently dominate the field of systematics. The enhancement of the accessibility of morphological data by indexing previously published data and adding tags to the characters reduces the entry level requirements for their use and allows for the critical recycling of datasets for future studies. By crossing gene content, phylogenomic and morphological data we have been able to evaluate alternative scenarios of the relationships of animal phyla. This combined approach resulted in very strong support for the Porifera-sister hypothesis in the vast majority of combinations of sources of data and analytical methods.
Projektbezogene Publikationen (Auswahl)
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A new sponge genus from the Chengjiang biota with an intriguing combination of skeletal characters. PalZ, 97(3), 443-450.
Chen, Ailin; Porras, Luis; Ma, Haidan; Hou, Xianguang & Wörheide, Gert
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Exploring genome gene content and morphological analysis to test recalcitrant nodes in the animal phylogeny. PLOS ONE, 18(3), e0282444.
Juravel, Ksenia; Porras, Luis; Höhna, Sebastian; Pisani, Davide & Wörheide, Gert
