Genetic variation in two<i>Chamaecrista</i>species (Leguminosae), one endangered and narrowly distributed and another widespread in the Serra do Espinhaço, Brazil
Bibliographic record
Abstract
The Serra do Espinhaço in Brazil is under continuous and increasing levels of human disturbance. It has a large number of endemic plant species such as Chamaecrista semaphora (Irwin and Barneby), an endangered species with extremely narrow range. We studied the genetic diversity of C. semaphora and compared it with Chamaecrista mucronata (Spreng.) Irwin and Barneby, a widespread congeneric species distributed over the entire Serra do Espinhaço, in an attempt to provide information for conservation strategies. Two populations of C. mucronata and the only two known populations of C. semaphora from Serra do Cipó were screened for variability using random amplified polymorphic DNA (RAPD) markers. Populations of C. semaphora exhibited a lower percentage of polymorphic markers (16.9%) and Shannon’s Diversity Index (H′pop= 0.124) than C. mucronata populations (43.3% and H′pop= 0.299). Most of the genetic variability of both species studied was distributed within populations; C. semaphora populations (ΦST= 0.198) were less divergent than C. mucronata populations (ΦST= 0.378). The risk of extinction for C. semaphora is large owing to its low level of genetic diversity compared with its widespread congener and because of increasing habitat destruction. Both populations of C. semaphora urgently need protection to maximize the genetic diversity of this species and diminish further substantial loss within the populations.
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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".