Drainage reversal with no lineage expansion, a case of competitive exclusion? The genetics of<i>Galaxias maculatus</i>in two connected trans-Andean systems
Bibliographic record
Abstract
Abstract Understanding how historical and contemporary processes lead to genetic differentiation among populations is a fundamental goal of evolutionary and conservation biology. This study focuses on Galaxias maculatus, a widely distributed fish exhibiting diadromous and freshwater resident forms. We examine the genetic differentiation among resident populations from the Manso River System, a trans-Andean system which thus went through drainage reversal following the Last Glacial Maximum (LGM), and resident and diadromous populations from the connected Puelo River that drains into the Pacific Ocean. Single nucleotide polymorphic (SNP) markers revealed that resident populations from the Manso River System are genetically distinguishable from the diadromous and resident populations from the Puelo River. This suggests that G. maculatus from the Manso River System likely colonized the area from a glacial refugium east of the Andes and did not expand downstream during drainage reversal, whereas the populations from the Puelo River colonized the area from glacial refugia west of the Andes. The populations from the Manso River exhibited lower genetic diversity than the Puelo River populations. Galaxias maculatus resident populations in Patagonia are decreasing due to anthropogenic factors. The Manso River System resident populations are susceptible to these factors and may show further decreases in genetic diversity.
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 | 0.001 |
| 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 | 0.000 | 0.001 |
| 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".