Molecular phylogenetic evidence for multiple dispersal events in gomphocerine grasshoppers
Bibliographic record
Abstract
The gomphocerine grasshoppers, comprising over 1000 species, occur on all continents excepting Australia and Madagascar. This work provides an independent examination of previous accounts of their taxonomic relationships and intercontinental connections, focusing on selected North American and Eurasian taxa. Our study is based on portions of four mitochondrial genes (coding for cytochrome b, cytochrome oxidase subunits I and II, and NADH dehydrogenase subunit V) which were sequenced and phylogenetically analyzed using weighted and unweighted maximum parsimony, maximum likelihood and Bayesian methods. Maximum resolution was achieved using weighted parsimony (counting transversions at third codon positions only) and Bayesian methods, and treating all four sequences, totalling 1892 bp, as a unit. The subfamily is provisionally accepted as monophyletic. The tribe Chrysochraontini is monophyletic, whereas the monophyletic status of Aulocarini and Dociostaurini is unclear. Tribes, Arcypterini, Chorthippini and Gomphocerini, are not monophyletic and require further scrutiny. Regarding biogeographic origins of the subfamily, our molecular data generally support Vickery's assertion that there were multiple periods of dispersal, most likely from Eurasia to North America. Assigning the range 50 to 70 Mya to the time of gomphocerine divergence, we provide estimates of the times of these biogeographic events.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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) | 0.001 | 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".