Does a negative genetic correlation between wing morph and early fecundity imply a functional constraint in Gryllus firmus
Bibliographic record
Abstract
We tested the hypothesis that wing muscle size and triglyceride production mediate a lifehistory trade-off between wing morph (or flight capability) and early fecundity. Roff et al. recently selected for lower number of eggs laid in the first week by Gryllus firmus (sand cricket) and reported a correlated increase in long-winged (and presumably flight-capable) females, but did not test structural or energetic reproductive costs associated with flight capability. We used ovary weight of virgin crickets as an index of their early fecundity and dorsal longitudinal flight muscle (DLM) weight as a quantitative measure of flight muscle status. A preliminary experiment indicated that DLM weight is highly correlated with other measures of DLM status (colour, histolysis state, size). We used a haemolymph assay for acylglycerol concentration as an index of mobile triglyceride derivatives thought to provide energy for flight. Both DLM weight and acylglycerol concentration were negatively related to ovary weight of long-winged crickets, indicating wing muscle size and triglyceride concentrations mediate reproductive costs. In short-winged females, only DLM weight had a negative phenotypic relationship with ovary weight. The heritability of DLM weight and acylglycerol concentration are unknown, so we used the direction and size of standardized differences between base and selected populations to test whether DLM weight and acylglycerol concentration are negatively genetically correlated with ovary weight. Acylglycerol concentration and DLM weight increased in the population selected for low numbers of eggs laid within both wing morphs. Large standardized differences in short-winged females provide strong corroborative evidence of a genetic relationship between early fecundity and flight capability. These results indicate negative genetic correlations between wing morph and early fecundity reflect inherited variation in costs of early reproduction, related to physiological investment in flight capability (flight muscle size and triglyceride allocation), rather than being an arbitrary assumption of a life-history trade-off model.
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 | 0.000 |
| 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) | 0.002 | 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".