Complex post-larval dispersal processes in Atlantic cod revealed by age-based genetics and relatedness analysis
Bibliographic record
Abstract
Population connectivity among adult marine organisms is often attributed to dispersal during the egg/larval stage. However, post-larval dispersal may also influence connectivity, particularly when juvenile nursery habitats are separated from adult spawning habitats. Here we used age-based population genetics and kinship analysis to explore changes in population connectivity across life-history stages in Atlantic cod Gadus morhua. We genotyped 364 adult cod from the northwest Atlantic and 671 age-0 juveniles from 18 sites around eastern Newfoundland, with 72 and 15 microsatellite loci, respectively. Adult cod genotypes exhibited more population structure than was detected in juveniles across similar spatial scales. Both age classes had similar allelic diversities, but juveniles exhibited less genetic linkage and fewer departures from Hardy-Weinberg expectations than adults at the same loci. We detected significant kinship relationships in adult cod only within sampling locations, but 1 putative pair of juvenile kin was separated by >500 km. Collections of adults also displayed higher group relatedness compared to juveniles. Genetic differences between age classes are likely due to a combination of non-random mortality and non-random sorting of admixed juveniles into different adult habitats. Many studies overlook post-larval dispersal as a factor of marine population connectivity, but pre-adult relocation may be demographically and adaptively significant, in cod and other species.
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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 | 0.001 | 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) | 0.000 | 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".