Vicariant events in the montane hummingbird genera <i>Augastes</i> and <i>Schistes</i> in South America
Bibliographic record
Abstract
We assessed the evolutionary histories of two hummingbirds, Augastes scutatus and Augastes lumachella, endemic to the highlands of the Espinhaço Range in Brazil. These hummingbirds are considered relictual taxa with phylogenetic affinities to members of the genus Schistes from the Andean region. We reconstructed phylogenetic relationships of Augastes through the use of mitochondrial DNA and nuclear sequences within the Polytminae hummingbird clade, and found that the inferred phylogenetic reconstructions placed A. scutatus as the sister species of A. lumachella and Augastes as sister to Schistes geoffroyi from the northern Andes, as previously suggested by similarities found in plumage and morphology. Our results are consistent with an initial divergence of Augastes and Schistes lineages in the Late Miocene, associated with geological and climatic changes across the South American landscape. A Late Pliocene vicariant event between A. scutatus and A. lumachella may be associated with climatically distinct environmental conditions influencing the local differentiation and adaptation of ancestral Augastes populations. Our findings represent additional important evidence of vicariant events between east and west in southern South America, and between north and south within the Espinhaço Range of Brazil.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".