npj Complexity - Priority effects inhibit the repeated evolution of phototrophy

Microbes are everywhere – on your skin, in your gut, in the soil beneath your feet, even floating in the air you breathe. Most people think of microbes in simple terms: some make you sick, while other...

The phyla making up the major animal clade of Spiralia have been clear since the advent of molecular phylogenetics; the relationships between these spiralian phyla have not. The lack of consensus over the relationships between these important animal phyla might be a clue implying their emergence in an explosive radiation. Focusing on the five largest spiralian phyla (Annelida, Brachiopoda, Mollusca, Nemertea and Platyhelminthes) and using two phylogenomic datasets, we have applied site-bootstrapping and taxon-jackknifing to explore this example of taxonomic instability. Analyses on the 105 possible rooted trees relating them showed that interphylum branches are very short. Preference for rooting Spiralia on Platyhelminthes is a long-branch artefact. Most analyses on the 15 unrooted trees showed a preference for the same topology but the support over other solutions was non significant. We conclude that the spiralian phyla emerged in rapid succession resulting in a difficult to resolve radiation. The deep history we infer for Spiralia has wide ranging implications for our interpretation of Cambrian fossils and for the evolution of traits such as biomineralization, segmentation and larvae. Impact Statement Analyses of two independent phylogenomic datasets suggest an explosive radiation at the origin of Spiralia, with implications for understanding the group’s evolutionary history. ### Competing Interest Statement The authors have declared no competing interest.

Exploring rates of change and modes of evolution in blastozoan echinoderms

Global Invertebrate Genome Alliance VI, July 2026, Philippines

npj Biodiversity - The flounder effect: disparities in taxonomic and ecological study intensity across extant and fossil marine organisms hamper conservation

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Call for papers “…it is not too much to say that when we have mastered the difficulties presented by the peculiarities of island life we shall find it comparat

We examined the external shape and cross-sectional morphology of limb bones in 133 salamander species spanning the ecological and phylogenetic breadth of Caudata. We find that adaptations for aquatic...

Personal website of Dr. Peder M. Isager