Relaxed selection and the evolution of Chasmogamous flower of Impatiens capensis
Bibliographic record
Abstract
We exploited ecotypic variation in Impatiens capensis to test the hypothesis that mutation accumulation accompanying relaxed selection on the chasmogamous (CH) flower leads to more variable flower shapes and smaller flowers. Sun ecotype populations of this species occur along sunny riverbanks and marshes and produce both CH and cleistogamous (CL) flowers, while shade ecotype populations occur in shady forest floors and produce only CL flowers. In the shade ecotype, it is assumed that selection on the CH flower has been relaxed. Seedlings from population samples of the two ecotypes exhibited different first internode growth responses to low ratio of red:far-red light characteristic of ecotypic differentiation to either sunny or shady conditions, helping to verify historical illumination conditions in the populations. We examined the CH floral mutation accumulation hypothesis by comparing the shape and size of the modified CH flower sepal under greenhouse conditions that triggered CH flowering in plants of both ecotypes. Contrary to our predictions, geometric morphometric analysis of sepal shape variation levels indicated little difference between the shade and sun ecotypes. We suggest that mutations that influence CH flower shape may have pleiotropic effects on structures or processes that remain under selection even when the CH flowers are not produced. On the other hand, sepal size was significantly smaller in the shade ecotype populations. In the case of CH sepal size, the mutational effects appear to be directional, towards the production of smaller sepals, and likely would be deleterious if shade ecotype plants encountered sunnier conditions where CH flowers could be produced.
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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 | 0.000 |
| 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".