Incubation temperature effects on hatchling growth and metabolic rate in the African spurred tortoise,<i>Geochelone sulcata</i>
Bibliographic record
Abstract
We tested competing hypotheses regarding the persistence of temperature-dependent sex determination (TSD) in the African spurred tortoise (Geochelone sulcata (Miller, 1779)), by measuring the effects of incubation temperature (Tinc) on a suite of physiological and behavioral endpoints, including resting metabolic rate, yolk-to-tissue conversion efficiency, posthatching growth, and temperature preference. Correlations of these variables with Tinccould lend support to the hypothesis that TSD persists owing to sex-specific benefits of development at specific temperatures, whereas absence of Tinceffects support the null hypothesis that TSD persists simply because selection favoring alternate sex determining mechanisms is weak or absent. The metabolic rate Q10value exhibited temporal variation and was higher immediately after hatching compared with 40 or 100 days posthatching, and mass conversion efficiency varied among clutches. Incubation temperature correlated inversely with duration of embryonic development, but did not influence yolk conversion efficiency, growth, or resting metabolic rate. Thus, our results provide little evidence indicating contemporary benefits of TSD, suggesting that TSD in G. sulcata is no longer evolutionarily adaptive but persists because selection against it and in favor of other sex-determining mechanisms is weak, or that TSD is an adaptive trait but for reasons not elucidated by this study.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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".