Evolutionary potential of a large marine vertebrate, the lemon shark («Negaprion brevirostris»)
Bibliographic record
Abstract
Understanding the evolutionary processes that dictate biological diversity in nature is critical to making predictions about how animals will respond to future environmental change. Despite this, few have been able to overcome the logistic constraints that accompany such studies in the wild. Large marine vertebrates are particularly troublesome owing to their cryptic nature and high vagility, which also leads some researchers to believe that local adaptation will be rare. And yet cases are mounting in which marine organisms, with high dispersal potential, are phenotypically divergent over small spatial scales. In this thesis, I use quantitative genetic methods to provide supporting evidence for local adaptation in a large marine vertebrate, the lemon shark (Negaprion brevirostris). My study takes advantage of samples obtained from an isolated lemon shark nursery lagoon since 1995 (Bimini, Bahamas), as well as data collected opportunistically at another site in the Florida Keys (Marquesas Key). This system is particularly interesting owing to the differences in juvenile body size and growth rate between sites. I begin this thesis by using newly developed microsatellite markers to reconstruct population pedigrees, and by then characterizing the mating system of the lemon shark in light of early life history differences. Mating system patterns were consistent among sites ─ adult females showed high fidelity to each nursery for parturition and mated with multiple males (i.e., polyandry). The observed polyandry could not be explained by direct or indirect genetic benefits, and so I instead suggest that females mate multiply to avoid harassment by males. I next estimated selection and heritability associated with morphological traits in sharks at Bimini, finding that small, slow growing individuals were favored, and that some of these traits were heritable. These findings support a scenario of “constrained” local adaptation, whereby juveniles are partially adapt
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".