Detection of hybridization between Castanea dentata (Marsh.) Boorkh. and non-native congeners in Ontario
Bibliographic record
Abstract
The fungal pathogen, 'Cryphonectria parasitica', introduced to North America in the early 20th century, has reduced natural populations of 'Castanea dentata' (American chestnut) by 99 percent. The remaining individuals are often interspersed with non-native ' Castanea' species; however, the existence of hybrids has not been tested. My research characterizes four putative parental species morphologically and genetically (randomly amplified polymorphic DNA), and examines the remnant ' Castanea' populations of southern Ontario for hybrids. Both methods were able to distinguish between 'C. dentata' and three non-native ' Castanea' species, but only the molecular techniques could clearly identify nonnative and hybrid 'Castanea' trees in Ontario forests. One hybrid of American and Japanese chestnut species was detected in an Ontario woodlot, showing for the first time that non-native genetic material is entering the Canadian 'C. dentata' population. Canadian chestnut is also somewhat distinct from American chestnut in morphology and genetics.
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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 | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 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".