A family history: effects of parental age on offspring life-history traits in bighorn sheep
Bibliographic record
Abstract
Long-term fitness effects of parental age could affect population dynamics, as age structure can vary considerably over time. Few studies of wild animals, however, have examined the possible long-term fitness consequences of parental age. Based upon 50 years of data on wild bighorn sheep, we investigated how parental age affected three offspring traits-mass at three years, longevity, and female lifetime reproductive success. We also tested for a survival filter which could mask or increase fitness effects of parental age. Our results showed a significant, quadratic negative association between maternal age, offspring longevity and female lifetime reproductive success. Offspring born to mothers aged 5 to 6 yr lived about 2 yr longer and weaned about 1.5 lambs more than siblings born to mothers aged 12 to 13 yr. The effect of paternal age was not significant. There was also a positive association between the longevity of mothers and offspring. We did not detect any effects of parental age on mass at three years for offspring of either sex. These results demonstrate the presence of persistent maternal age effects in a long-lived species. The sex-specific effects support the importance of analyzing maternal and paternal age effects separately, as well as effects on female and male offspring. This study advances our understanding of evolutionary processes and population dynamics in wild long-lived mammals.
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How this classification was reachedexpand
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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".