Patterns in the assembly of temperate forests around the Northern Hemisphere
Bibliographic record
Abstract
Recent studies of Northern Hemisphere biogeography have highlighted potentially significant differences between disjunction patterns in plants versus animals. To assess such differences, we compiled a larger sample of relevant plant phylogenies from which disjunction patterns, ancestral areas and directions of movement could be inferred. We considered 66 plant clades with species variously endemic today to eastern Asia (EA), Europe (including southwestern Asia), eastern North America (ENA), and/or western North America (WNA). Within these clades we focused on 100 disjunctions among these major areas, for 33 of which absolute divergence times have also been inferred. Our analyses uphold the view that disjunctions between EA and ENA are exceptionally common in plants, apparently more so than in animals. Compared with animals, we find few disjunctions between EA and WNA, consistent with increased extinction in WNA or failure of some groups to colonize that region. Taken at face value, our data also support the view that many temperate forest plant groups originated and diversified within EA, followed by movement out of Asia at different times, but mostly during the last 30 Myr. This favours Beringia over a North Atlantic land bridge as the primary path between the Old World and the New World. Additional studies are needed, especially to evaluate the impacts of differential extinction on these patterns, to more confidently establish divergence times, and to assess the statistical significance of these findings. Fortunately, many more plant groups show relevant disjunction patterns and could soon be added to such analyses.
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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 | 0.001 | 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 | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".