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Background And Aims: Resolving the phylogeny of hornworts is critical in understanding the evolution of key morphological characters that are unique to the group, including the pyrenoid. Extensive phylogenomic analyses have revealed unexpected complexities in the placement of Leiosporoceros, the previously identified sister taxon to other hornworts. We explore the role of incomplete lineage sorting (ILS) and ancient reticulation in resolving interrelationships and understanding the diversification and evolutionary processes within hornworts.
Methods: Using the GoFlag probe set, we sequenced 405 exons representing 234 nuclear genes, sampling 79 hornwort specimens, including representatives of all hornwort genera. We inferred the species phylogeny from gene tree analyses using concatenated and coalescence approaches, assessed ancient reticulation and ILS, and estimated the timing of divergences based on fossil calibrations.
Key Results: Extreme levels of gene tree incongruence challenge the sister relationship of Leiosporoceros to other hornworts. This phylogenetic discordance is due to ILS and ancient reticulation, the latter revealed using a network approach to identify evidence of gene flow among hornwort lineages. Hornwort diversification began in the Carboniferous with widespread family-level divergences during the mid-Cretaceous and Palaeogene.
Conclusions: ILS and ancient reticulation are identified as important in hornwort evolution. Patterns of hornwort diversification parallel those in other plants groups (e.g. liverworts, mosses, ferns and gymnosperms). Two scenarios on pyrenoid evolution are plausible based on the variable position of the pyrenoid-free Leiosporoceros. Pyrenoids were retained from a green algal ancestor and are plesiomorphic, or they evolved in response to the substantial drop in atmospheric CO2 levels during the Carboniferous as has been hypothesized in other photosynthetic organisms. Both hypotheses require losses and gains during hornwort speciation.
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http://dx.doi.org/10.1093/aob/mcaf002 | DOI Listing |
Mol Phylogenet Evol
September 2025
USDA Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Crop Genome Informatics Laboratory, 819 Wallace Rd, Ames, 50011, IA, United States. Electronic address:
Contradictory lines of evidence have made it difficult to resolve the phylogenetic history of the legume diversification era; this is true for the backbone topology, and for the number and timing of whole genome duplications (WGDs). By analyzing the transcriptomic data for 473 gene families in 76 species covering all six accepted legume subfamilies, we assessed the phylogenetic relationships of the legume backbone and uncovered evidence of independent whole genome duplications in each of the six legume subfamilies. Three subfamilies - Cercidoideae, Dialioideae, and Caesalpinioideae - bear evidence of an allopolyploid duplication pattern suggestive of ancient hybridization.
View Article and Find Full Text PDFBMC Plant Biol
August 2025
Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, The University of Gdańsk, Wita Stwosza 59, 80-308, Gdansk, Poland.
Background: The taxonomy of Paphiopedilum-a diverse group of slipper orchids-has long posed challenges due to high morphological variability and conflicting phylogenetic signals. Despite intensive research, a clear and stable infrageneric classification remains unresolved.
Results: We present an integrative phylogenetic framework based on multiple nuclear low-copy genes (XDH, PHYC, LFY, RAD51, ACO, DEF4), ITS and plastid (matK) sequences, supported by morphological and biogeographical data.
Mol Phylogenet Evol
August 2025
Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, USA; Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA.
Lake Baikal ranks among the world's most species-rich freshwater ecosystems; however, the evolutionary histories of endemic taxa remain poorly understood. The unique abiotic environments of Lake Baikal include the only bathybenthic, bathypelagic, and deep hydrothermal vent communities in freshwater, each of which supports species with derived morphological and physiological traits. As the only known vertebrate radiation endemic to a non-tropical ancient lake, Baikal sculpins represent an underappreciated resource for investigating evolutionary processes that underlie adaptive radiation.
View Article and Find Full Text PDFMol Phylogenet Evol
August 2025
Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Reticulate evolution complicates phylogenetic reconstruction and obscures species delimitation. Investigating gene flow and its evolutionary consequences across the phylogenetic breadth of the genus provides critical insights into the mechanisms causing diversification within this lineage. By utilizing RAD-seq data from 39 Castanopsis species, we reconstructed phylogenetic relationships through both concatenation- and coalescent-based methods.
View Article and Find Full Text PDFNat Commun
August 2025
Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations/State Key Laboratory of Plant Diversity and Specialty Crops, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
Polyploidy and subsequent post-polyploid diploidization (PPD) are key drivers of plant genome evolution, yet their contributions to evolutionary success remain debated. Here, we analyze the Malvaceae family as an exemplary system for elucidating the evolutionary role of polyploidy and PPD in angiosperms, leveraging 11 high-quality chromosome-scale genomes from all nine subfamilies, including newly sequenced, near telomere-to-telomere assemblies from four of these subfamilies. Our findings reveal a complex reticulate paleoallopolyploidy history early in the diversification of the Malvadendrina clade, characterized by multiple rounds of species radiation punctuated by ancient allotetraploidization (Mal-β) and allodecaploidization (Mal-α) events around the Cretaceous-Paleogene (K-Pg) boundary.
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