Genetic Structure, Evolutionary History, and Conservation Units of Bull Trout in the Coterminous United States
Bibliographic record
Abstract
Abstract The bull trout Salvelinus confluentus is a broadly distributed char in northwestern North America that has undergone significant population declines. This species is currently protected under the Endangered Species Act across its range in the coterminous United States. To clarify patterns of phylogenetic structure and to assist with identification of conservation units, we examined genetic variation within and among 75 representative bull trout populations sampled throughout the USA. Genealogies from a 520‐base‐pair portion of the mitochondrially encoded NADH dehydrogenase 1 gene (ND‐1) revealed reciprocal monophyly between coastal and interior lineages that differed by 1.34% in DNA sequence. The geographic distribution of the two lineages was divided by the Cascade Mountains, a pattern that likely reflects postglacial dispersal from separate glacial refugia. Analysis of microsatellite variation revealed that 76% of populations had an estimated effective population size less than 50 and indicated high divergence among populations caused by genetic drift (average genetic differentiation index FST = 0.32) and mutation (average genetic differentiation index RST = 0.58). Concordant phylogeographic and phylogenetic patterns observed with microsatellite and mitochondrial DNA analyses provided evidence for two to six bull trout lineages that largely reflect historic patterns of gene flow and isolation among populations. These lineages can be further subdivided into finer‐scale units due to the extremely low dispersal among populations and small effective population sizes. In fact, Bayesian analysis of population structure identified an optimal solution of 69 genetically different groups. Based on these results, we believe that conservation efforts should ideally be focused on the 118 bull trout core areas originally identified in the draft Endangered Species Act recovery plan, which are broadly defined as metapopulations. We provide examples of how other data, such as unique life history forms and ecological setting, can be used in combination with our genetic results to refine the U.S. Fish and Wildlife Service's hierarchical conservation strategy for bull trout.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".