Intraspecific genetic variation, population structure, and species diversity in the Carchesium Polypinum species complex
Bibliographic record
Abstract
Currently, the distribution of eukaryotic protists is a matter of intense debate. One side of the argument states that because of their small size, protists have the ability to disperse across geographic boundaries. Consequently, geographically structured populations and genetic variation are not expected. The other side argues that some of the bigger protists have limited dispersal and are therefore endemic with limited gene flow. The purpose of this thesis was to investigate the intraspecific genetic diversity of the ciliate ' Carchesium polypinum' (Subclass: Peritrichia) and determine whether that diversity mapped onto the geography of the regions sampled. Sampling was carried out mostly in river basins of Southwestern Ontario, but samples were also obtained from British Columbia, North Carolina, and England. Three nuclear markers - internal transcribed spacer (ITS) 1, ITS2 and the hypervariable region of the large subunit rRNA (28S) - and one mitochondrial gene - cytochrome c oxidase subunit I ('cox-1') - were used for the population-level analyses. This is the first time that the 'cox-1' gene is used on a ciliate other than ' Tetrahymena' and 'Paramecium'. The results indicated that 'C. polypinum' harbors a large degree of genetic diversity; however, in most cases this diversity is not geographically partitioned. This is one of the first times that population genetics analyses are employed on protists. Furthermore, quantitative as well as qualitative analyses, based on both morphological characters and gene sequences of the small subunit rRNA (18S), uncovered robust evidence that 'C. polypinum' is a cryptic species complex with no fewer than six members.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 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".