Re-evaluating the eukaryotic Tree of Life with independent phylogenomic data

Understanding the phylogenetic relationships among eukaryotic lineages is essential for tracing the evolution of key phenotypic traits and inferring the nature of the Last Eukaryotic Common Ancestor. While phylogenomic analyses have clustered eukaryotic taxa into several well-supported major supergroups, the relationships among them remain largely uncertain. Phylogenetic signal erosion over deep time and limited available taxon sampling are among the possible causes. However, most previous studies rely on variations of the same core protein dataset, hence containing the same potential systematic biases. Here, we reconstructed the eukaryotic Tree of Life using a largely independent, marker-rich dataset derived from highly conserved Benchmarking Universal Single-Copy Orthologs. Unlike previous collections, our 277-marker supermatrix minimizes ribosomal protein representation and shares less than 25% overlap with previous datasets. State-of-the-art analyses of this dataset confirm most eukaryotic supergroups previously observed, but suggest different positions for some lineages. Notably, Telonemia clusters with Haptophyta rather than SAR (Stramenopiles-Alveolata-Rhizaria), and Ancyromonadida and Malawimonadida form a monophyletic group at the base of the Opimoda. Our results highlight the importance of analyzing independent phylogenomic datasets and support the hypothesis that extant eukaryotic diversity encompasses a small number of high-rank, supergroup lineages.