Does oxidative stress mediate the trade‐off between growth and self‐maintenance in structured families?
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Summary 1. Life‐history theory predicts a trade‐off between growth and self‐maintenance. However, little is known about the underlying mechanisms. Oxidative stress, the imbalance between the production of reactive oxygen species (ROS) during normal metabolic processes and the level of antioxidant defences, is a potential mechanism. 2. In many altricial birds asynchronous hatching creates different castes of progeny as a hedge against developmental and environmental uncertainty (a ‘structured’ family). Older, ‘core’ offspring and later hatched ‘marginal’ offspring consequently experience contrasting levels of resource availability during development. To be adaptive the phenotypic handicap incurred by marginal offspring must be reversible when conditions allow. 3. Dietary‐derived antioxidants are an important component of antioxidant defences, which modulate oxidative damage arising from normal metabolic processes such as growth. Dietary antioxidants could therefore be important determinants of trade‐offs during growth, with the balance of these trade‐offs differing between core and marginal offspring. 4. To investigate this, we manipulated brood size and structure as well as antioxidant availability (by vitamin and mineral supplementation), then measured growth and oxidative damage in nestling red‐winged blackbirds Agelaius phoeniceus . 5. We found that individuals supplemented with dietary antioxidants allocated these extra resources to increasing growth rate, rather than reducing oxidative damage. Irrespective of hatch rank, nestlings that received supplementary antioxidants grew faster than controls, despite no difference in their begging behaviour or parental provisioning rates. There was no overall difference in the level of lipid peroxidation (malondialdehyde; MDA) in the blood plasma of supplemented and control chicks, but among marginal offspring those that received an antioxidant supplement had lower plasma MDA. Antioxidant supplementation did not affect nestling survival to fledging age. 6. These novel results support the idea that oxidative stress may play a central role in the trade‐off between growth and self‐maintenance. Moreover, they further highlight the importance of physiological costs in the evolution of life‐histories and propose a role for oxidative stress in the adaptive basis of the structured family.
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.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it