Phylogeographic patterns in<i>Packera subnuda</i>reveal an east–west divergence along the Continental Divide and reduced haplotype diversity in northern populations
Bibliographic record
Abstract
Packera subnuda (DC.) D.K. Trock & T.M. Barkley is a cordilleran species that is unusual within Packera in possessing diverse cpDNA haplotypes but no intrapopulational cpDNA diversity in the populations so far examined. In an effort to determine what factors are shaping this lack of diversity and whether it persists throughout the species, we sampled extensively throughout the range of the species. Unlike previous results, new population samples were not all monomorphic for cpDNA and some contained diverse haplotypes. Overall, the haplotype diversity pattern revealed, with one exception, a split into two groups separated by the Continental Divide. The exception (Beartooth Mountains, Wyo., USA) suggests the key factor in shaping the groups’ distributions may be the proximity to prairie populations of Packera species that increases the likelihood of hybridization. The pattern of diversity in ITS repeat type revealed in previous studies was also examined in more detail, with diversity found at both the intraindividual and intrapopulational level. ITS revealed a similar east–west separation into two groups on either side of the Continental Divide. Overall, the pattern suggests ancient hybridization injected haplotype and repeat type diversity into the species and that this diversity has since been reduced by the effects of drift in small populations, most significantly in populations at the northern and eastern edge of the range.
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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".