A molecular phylogenetic analysis of the grasshopper genus Melanoplus Stål (Orthoptera: Acrididae) – an update
Bibliographic record
Abstract
This research expands upon our previous molecular phylogenetic analysis of the genus Melanoplus by incorporating additional mitochondrial genes, taxa and specimens. Included are two monotypic genera suspected of close affiliation with Melanoplus Phoetaliotes and Bohemanella. Portions of four mitochondrial genes, coding for cytochrome b, cytochrome oxidase subunits I and II, and NADH dehydrogenase subunit II, were sequenced and phylogenetically analyzed using (weighted and unweighted) parsimony and neighbor-joining methods. Maximum resolution of relationships was achieved using weighted parsimony and by treating all sequences, totaling 1716 base pairs, as a unit.The following large clades emerged in parsimony analyses, supported by moderate to poor bootstrap values: A — sanguinipes, femurrubrum, devastator, gaspesiensis, fasciatus, borealis, madeleineae, dawsoni; B — packardii, foedus, angustipennis, gladstoni, aspasmus; C — bivittatus, franciscanus, keeleri, calidus, littoralis, differentialis; D — infantilis, alpinus, aridus, Phoetaliotes, scudderi; and E — confusus, Bohemanella, marginatus, microtatus. M. lakinus was basal to all species. Deviations from the conventional literature in which species are organized into species groups or series are discussed. It is concluded that many such groups are phylogenetically questionable; their validity warrants serious reconsideration.Two phenomena - a rapid burst (or bursts) of speciation occurring early in the genus' evolution and an absence of complete lineage sorting for certain closely related species - are nicely illustrated by Melanoplus. We provide evidence that the massive radiation that took place within the past 4 My, inferred previously by Knowles and Otte, extends to a wider base of taxa, beyond the particular species studied by these authors.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".