Overdominance interacts with linkage to determine the rate of adaptation to a new optimum
Bibliographic record
Abstract
Overdominance, or a fitness advantage of a heterozygote over both homozygotes, can occur commonly with adaptation to a new optimum phenotype. We model how such overdominant polymorphisms can reduce the evolvability of diploid populations, uncovering a novel form of epistatic constraint on adaptation. The fitness load caused by overdominant polymorphisms can most readily be ameliorated by evolution at tightly linked loci; therefore, traits controlled by multiple loosely linked loci are predicted to be strongly constrained. The degree of constraint is also sensitive to the shape of the relationship between phenotype and fitness, and the constraint caused by overdominance can be strong enough to overcome the effects of clonal interference on the rate of adaptation for a trait. These results point to novel influences on evolvability that are specific to diploids and interact with genetic architecture, and they predict a source of stochastic variability in eukaryotic evolution experiments or cases of rapid evolution in nature.
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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".