Population genetic structure of the endangered Butler’s Gartersnake (<i>Thamnophis butleri</i>): does the Short-headed Gartersnake (<i>Thamnophis brachystoma</i>) exist in Canada?
Bibliographic record
Abstract
Understanding population genetic structure is fundamental to conservation of endangered species. It is particularly important when working with species that are morphologically conserved because strong genetic divisions could represent cryptic species. Butler’s Gartersnake (Thamnophis butleri (Cope, 1889)) is an endangered species in Canada, having a fragmented distribution and being restricted to southwestern Ontario. Furthermore, it is difficult to distinguish morphologically from a closely related species, the Short-headed Gartersnake (Thamnophis brachystoma (Cope, 1892)). We use mitochondrial DNA (mtDNA) and seven microsatellite DNA loci to evaluate the genetic structure of Canadian T. butleri populations and to test for the presence of T. brachystoma in one of these populations. All individuals had the same mtDNA haplotype, and there was no evidence of multiple, syntopic genetic clusters, thereby rejecting the hypothesis that T. butleri and T. brachystoma co-exist in Canada. Two different model-based assignment tests using microsatellite DNA data suggest that there are four to five genetically distinct clusters of T. butleri (FST from 0.12 to 0.20). We provide the first population genetic study of T. butleri in Canada and refute the presence of T. brachystoma. Our results may provide guidance on recovery strategies for this species and identify areas to target fine-scale genetic analyses.
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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".