Genome-wide analysis of the human head louse ( Pediculus humanus capitis ) reveals geographically structured genetic populations
Bibliographic record
Abstract
The human head louse ( Pediculus humanus capitis ) is an obligate ectoparasite of humans and has the potential to uncover aspects of human history that cannot be directly inferred from genetic data derived from humans. Previous studies have shown that global louse populations exhibit restricted patterns of genetic variation. However, these studies were restricted both genetically and lacked a global sampling. With the aim of capturing the genetic diversity of head louse populations from around the world, we generated whole genome sequences of human head lice from 43 countries, spanning five continents and Oceania, to determine if louse nuclear diversity mirrors its mitochondrial haplotypes or if population genetic structure, genetic diversity, and population connectivity are associated with geographical regions or host behavior. Here we show that there are five nuclear genetic clusters that are associated with large geographical regions, either at continental or intercontinental levels. High genetic variation was found between African and non-African individuals and the highest genetic diversity was found in samples from sub-Saharan Africa, similar to that of humans. Unlike the mitochondrial clades examined in previous studies, nuclear genetic clusters of lice examined here are highly structured based on geography (continentally and major regions within continents). Results from our genome analyses revealed that host-mediated global dispersal as the likely primary process in shaping diversity and maintaining genetic population boundaries within the nuclear genome of the human head louse.
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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 | 0.001 |
| 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".