The varix: evolution, distribution, and phylogenetic clumping of a repeated gastropod innovation (vol 180, pg 732, 2017)
Bibliographic record
Abstract
A recurrent theme in evolution is the repeated, independent origin of broadly adaptive, architecturally and functionally similar traits and structures.One such is the varix, a shell-sculpture innovation in gastropods.This periodic shell thickening functions mainly to defend the animal against shell crushing and peeling predators.Varices can be highly elaborate, forming broad wings or spines, and are often aligned in synchronous patterns.Here we define the different types of varices, explore their function and morphological variation, document the recent and fossil distribution of varicate taxa, and discuss emergent patterns of evolution.We conservatively found 41 separate origins of varices, which were concentrated in the more derived gastropod clades and generally arose since the mid-Mesozoic.Varices are more prevalent among marine, warm, and shallow waters, where predation is intense, on high-spired shells and in clades with collabral ribs.Diversification rates were correlated in a few cases with the presence of varices, especially in the Muricidae and Tonnoidea, but more than half of the origins are represented by three or fewer genera.Varices arose many times in many forms, but generally in a phylogenetically clumped manner (more frequently in particular higher taxa), a pattern common to many adaptations.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.002 |
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".