Persistence of pelvic spine polymorphism in a panmictic population of brook stickleback (<i>Culaea</i> <i>inconstans</i>) in Alberta, Canada
Bibliographic record
Abstract
In the stickleback family (Gasterosteidae), divergence in pelvic morphology is typically associated with reproductive isolation and ecological niche specialization. In this study, we assessed whether reproductive isolation may be involved in the persistence of within-lake polymorphism in brook stickleback (Culaea inconstans (Kirtland, 1840)). We studied populations of brook stickleback in central Alberta, Canada, that are polymorphic for pelvic reduction (i.e., presence–absence of pelvic spines). We investigated the persistence of the pelvic polymorphisms over 40 generations in five lakes. We found that, of the five populations examined, the frequencies of pelvic phenotypes have remained unchanged in three populations, the polymorphism has persisted with significantly changed frequencies of pelvic phenotypes in one population, and the polymorphism has been lost in one population. Using 10 microsatellite loci, we observed low genetic divergence between individuals with and without pelvic spines in one lake, suggesting a lack of assortative mating among individuals with divergent pelvic phenotypes. This observation suggests that the pelvic polymorphism in brook stickleback persists due to balancing selection in the absence of reproductive isolation, although the selective forces were not evaluated. The significant changes in phenotypic frequencies in two populations are likely associated with environmental disturbances such as species introductions.
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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 | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".