Geographic variation of skeletal ontogeny and skull shape in the harbour porpoise (<i>Phocoena phocoena</i>)
Bibliographic record
Abstract
All extant porpoise species show paedomorphic skeletal traits. These traits are hypothesized to be connected with rapid growth to reproductive size and could thus show geographic variation according to ecological circumstances. To investigate this, skeletal ontogeny was compared among harbour porpoises from California, West Greenland, the inner Danish waters, and the Sea of Azov. Porpoises from California grew to larger sizes than Danish porpoises, which were again larger than Greenlandic porpoises, whereas Azov porpoises were smallest. Size differences were largely attributable to differences in timing of offset of growth. Expression of paedomorphosis followed the same pattern among populations and sexes as adult sizes; Californian porpoises were less paedomorphic than the other populations across all assessed traits, whereas porpoises from Azov were the most paedomorphic. We propose that the larger size and less profound paedomorphism seen in Californian porpoises are attributable to fluctuation of prey availability, owing to variation in upwelling on which productivity in Californian waters depends. Skull shapes after correction for allometry were significantly different among all populations, Sea of Azov porpoises being most divergent. There was no overlap of skull shapes between the Atlantic, the Pacific, and Azov, supporting the current division of harbor porpoises ( Phocoena phocoena (L., 1758)) into three subspecies ( Phocoena phocoena phocoena (L., 1758), Phocoena phocoena relicta Abel, 1905, and Phocoena phocoena vomerina Gill, 1865).
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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 | 0.000 |
| 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".