Molecular phylogenetics of circumglobal <i>Euphausia</i> species (Euphausiacea: Crustacea)
Bibliographic record
Abstract
The speciation history of members of the krill genus Euphausia with continuous circumglobal distributions was investigated by phylogenetic and molecular clock analyses of their mitochondrial DNA. Molecular clock estimates for divergence times of Antarctic and sub-Antarctic species of Euphausia of ~15 million years ago were fairly close to the time of formation of the Antarctic Convergence, consistent with their vicariant speciation. However, the confidence limits quantified for these time estimates were large at ~11 million and ~25 million years. A divergence time of between ~10 million years for Euphausia triacantha and Euphausia longirostris suggested that migration across oceanographic fronts like the Antarctic Convergence may also lead to speciation in krill. Genetic differentiation between Euphausia vallentini and Euphausia lucens was found to be relatively minor and occurred between 0.76 million and 1.65 million years ago. These species have overlapping ranges, suggesting that there is potential for sympatric genetic differentiation in krill.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".