304: Patrilineal Y‑chromosome drive in a Utah pedigree (67% male offspring)

Baldwin-Brown JG et al., Annual Review of Ecology and Systematics - Bayesian analysis of 76,445 Utah Population Database pedigrees identifies a patrilineal Y‑chromosome lineage producing a 2:1 male bias, consistent with segregation distortion. Key terms: segregation distortion, Y chromosome, sex ratio, Utah Population Database, Bayesian pedigree analysis.

Episode title:
Patrilineal Y‑chromosome drive in a Utah pedigree (67% male offspring)

Study Highlights:
We analyzed 76,445 anonymized human pedigrees from the Utah Population Database using a Bayesian pedigree-propagation algorithm (Warp), complemented by transmission disequilibrium testing, permutation and Monte Carlo simulations. These methods identified a single patrilineal Y-chromosome lineage with 89 informative transmissions that produced 60 male and 29 female offspring, a 67.4% male proportion. Warp and the TDT independently flagged the same family and permutation/Monte Carlo tests indicated the observed male bias was unlikely to arise by chance (p≈0.001–0.05). The pattern is consistent with a Y-linked segregation distorter and is discussed as a possible contributor to unexplained male infertility and human sex-ratio dynamics.

Conclusion:
A multi-method analysis of deep Utah pedigrees identifies a statistically significant male-biased patrilineal lineage consistent with a Y-linked segregation distorter in humans.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Signatures of sex ratio distortion in humans

First author:
Baldwin-Brown JG

Journal:
Annual Review of Ecology and Systematics

DOI:
10.64898/2026.02.04.702084

Reference:
Baldwin-Brown JG, Wesolowski S, Zimmerman RM, Peterson B, Tristani-Firouzi M, Hernandez EH, Aston KI, Yandell M, Phadnis N. Signatures of sex ratio distortion in humans. Annual Review of Ecology and Systematics. 2026. https://doi.org/10.64898/2026.02.04.702084

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

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QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript segments describing segregation distortion concepts, Warp Bayesian algorithm for detecting distorters, the UPDB/focal patrilineal lineage with 67.4% male offspring across 89 transmissions, TDT results, Monte Carlo validation, proposed Y-chromosome mechanisms (PRY cluster), and implications (male infe
- transcript topics: Segregation distortion concepts and Mendelian expectations; Warp Bayesian algorithm for detecting distorters in UPDB pedigrees; UPDB data and identification of a patrilineal Y-chromosome lineage with 60/29 across 89 transmissions; Transmission Disequilibrium Test (TDT) results; Monte Carlo validation of lineage bias (p ≈ 0.00138); Potential molecular mechanisms: PRY ampliconic gene cluster

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Identification of a patrilineal Y-chromosome distorter signal in humans using UPDB data (67.4% male across 89 transmissions in focal lineage)
- Warp Bayesian algorithm applied to UPDB pedigrees identifies putative distorter-carrying lineages (two male-biased families detected; six female-biased families)
- Focal patrilineal lineage across 89 informative transmissions yields 60 male and 29 female offspring (67.4% male)
- Transmission Disequilibrium Test (TDT) identifies the focal patrilineal lineage as significantly male biased (p ≈ 0.0249 after FDR; uncorrected p ≈ 0.00102)
- Monte Carlo simulations yield p ≈ 0.00138 for the focal lineage
- PRY gene cluster on the Y chromosome discussed as a prime mechanistic candidate for distortion

QC result: Pass.