The impact of obligate parthenogenesis on concerted evolution of the rDNA IGS in populations of Daphnia pulex
Bibliographic record
Abstract
Cyclic and obligate parthenogens of 'Daphnia pulex ' were isolated from populations in Southern Ontario and Michigan and used to survey variation in the intergenic spacer region (IGS) of ribosomal DNA (rDNA). A total of 24 distinct IGS haplotypes was identified from eight isolates used in this study. Mean number of haplotypes per isolate was lower for obligate isolates than for cyclic isolates, suggesting that there is a net loss of IGS haplotype variants in obligate parthenogens over time. Mean intraisolate genetic and nucleotide diversities were found to differ between cyclic and obligate isolates. However, mean sequence divergence did not differ significantly, suggesting that the differences in genetic and nucleotide diversities are due primarily to differences in number and frequency of IGS haplotypes. The results indicate that in the rDNA IGS of 'D. pulex,' unequal chromosomal exchange as a result of meiotic recombination is not the primary mechanism driving concerted evolution.
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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 | 0.000 | 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".