198. Long-term changes in genetic mean and genic variance and underlying allele frequencies in breeding programmes
Bibliographic record
Abstract
The infinitesimal model assumes that polygenic traits are influenced by (infinitely) many quantitative trait loci with (infinitely) small effects and that selection on such traits has minimal impact on the frequency of alleles at individual loci, hence minimal impact on genetic variance. Here we evaluated trends in genetic mean and genic variance for milk yield over 25 years in 9,403 proven and genotyped bulls from the Canadian Dairy Network. The results showed significant change in genetic mean and minor change in genic variance, supporting the infinitesimal model. A detailed analysis of SNP marker allele frequencies indicated sizeable changes at individual loci. We grouped the SNP markers by their initial allele frequency and direction of change, to indicate how these groups of makers contribute to changes in mean and variance in the analysed period of 25 years and predictions for the next 75 years showing sizeable changes in mean and variance.
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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 | 0.001 | 0.004 |
| 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 | 0.001 | 0.000 |
| Open science | 0.001 | 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".