Phylogenetic Inferences Based on nrDNA Sequences Support Five Morphospecies Within the Peltigera didactyla Complex (Lichenized Ascomycota)
Bibliographic record
Abstract
The Peltigera didactyla complex comprises species of section Peltigera with laminal and submarginal soredia. Three species (P. didactyla, P. lambinonii, and P. ulcerata) and one atypical variety (P. didactyla var. extenuata) are currently recognized within this complex. Phylogenetic inferences of the entire Internal Transcribed Spacer region (ITS) and the 5′ half of the gene encoding the large subunit of the rRNA reveal a robust structure within the complex. Under both the maximum parsimony and the maximum likelihood criterion, P. didactyla is resolved as a polyphyletic entity, whereas P. ulcerata, P. lambinonii, and P. didactyla var. extenuata are delimited as monophyletic entities. Peltigera didactyla var. extenuata appears basal within the group, whereas var. didactyla is nested within a clade that also comprises P. lambinonii and P. ulcerata. The polyphyly of P. didactyla is further characterized by the existence of populations that resemble var. extenuata, but differ by their brownish upper cortex. These populations, all from the boreal zone of Canada, compose a monophyletic group sister to the P. didactyla-P. lambinonii clade. For P. didactyla to satisfy a phylogenetic species concept, the var. extenuata is reinstated at the species level, and a new species, P. castanea, is described. Three populations sampled are characterized by unique sequences that may indicate the presence of additional cryptic taxa within the complex. A key to the accepted species is provided. The presence of P. lambinonii in Australia is confirmed and P. ulcerata is reported as new for Chile.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".