Multi-locus phylogeny of <i>Bryoria</i> reveals recent diversification and unexpected diversity in section <i>Divaricatae</i>
Bibliographic record
Abstract
Abstract In recent years, the genus Bryoria (Parmeliaceae, Lecanoromycetes) has been the subject of considerable phylogenetic scrutiny. Here we used information on six gene regions, three nuclear protein-coding markers (Mcm7, GAPDH and Tsr1), two nuclear ribosomal markers (ITS and IGS) and a partial mitochondrial small subunit (mtSSU), to examine infrageneric relationships in the genus and to assess species delimitation in the Bryoria bicolor/B. tenuis group in section Divaricatae. For this purpose, phylogenetic analyses and several of the available algorithms for species delimitation (ASAP, GMYC single, GMYC multiple and bPTP) were employed. We also estimated divergence times for the genus using *BEAST. Our phylogenetic analyses based on the combined data set of six gene loci support the monophyly of sections Americanae, Divaricatae and Implexae, while section Bryoria is polyphyletic and groups in two clades. Species from Bryoria clade 1 are placed in an emended section Americanae. Our study reveals that section Divaricatae is young (c. 5 My) and is undergoing diversification, especially in South-East Asia and western North America. Separate phylogenetic analyses of section Divaricatae using ITS produced a topology congruent with the current species concepts. However, the remaining gene regions produced poorly resolved phylogenetic trees and the different species delimitation methods also generated highly inconsistent results, congruent with other studies that highlight the difficulty of species delimitation in groups with recent and rapid radiation. Based on our results, we describe the new species B. ahtiana sp. nov., characterized by its bicolorous, caespitose, widely divergent thallus, conspicuously thickening main stems, well-developed secondary branches, and rather sparse third-order branchlets. Another new lineage, referred to here as B. tenuis s. lat., is restricted to western North America and may represent a new species recently diverged from B. tenuis s. str., though further work is needed.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".