Convergent and divergent evolution in rain-forest populations and communities of cyprinodontiform fishes (<i>Aphyosemion</i> and <i>Rivulus</i>) in Africa and South America
Bibliographic record
Abstract
When the African and American continents separated 65125 million years ago, populations and communities of plants and animals of the same lineage became isolated and evolved independently. Today, however, the cyprinodontiform fishes on the two sides of the Atlantic Ocean are morphologically similar, especially the American genus Rivulus and the African genus Aphyosemion. The evolutionary-inertia hypothesis is rejected as an explanation of this similarity because of evidence that the speciation process is ongoing. This study concerns processes that are probably responsible for the convergent and divergent evolution in the composition, structure, and dynamics of populations and communities, respectively. Basic data were obtained during a long-term study in the field, at the M'Passa biological station in Gabon and the St. Elie biological station in French Guiana. At the same time, rearing experiments were conducted from the Laboratoire d'Écologie at the Muséum National d'Histoire Naturelle in Paris. The composition, structure, and dynamics of the populations at M'Passa and St. Elie are similar. Parallel evolution of the habitats may explain the parallel evolution of the populations of cyprinodontiform fishes in Africa and America, leading to similar fish populations in similar habitats. Conversely, the composition, structure, and dynamics of the communities at St. Elie and M'Passa are different. The cause of this divergent evolution may be the absence of specific predators and competitors at M'Passa and the presence of highly specialized predators and competitors at St. Elie. The predators and competitors present at St. Elie all belong to the Characidae, a very successful group of fishes in America, without an equivalent in the Old World. Analogous processes of competitive exclusion are also observed in other orders of tropical American vertebrates: batrachians, reptiles, birds, and bats.
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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 | 0.001 |
| 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".