️ Episode 149: Cultural Hitchhiking and the Post‑Neolithic Y‑Chromosome Bottleneck

In this episode of PaperCast Base by Base, we explore how patrilineal social structures and intergroup competition can reshape genetic diversity, offering a cultural explanation for the striking male‑specific bottleneck observed 5,000–7,000 years ago across the Old World.

Study Highlights:
The authors synthesize anthropological theory, population genomics, and mathematical modeling to test whether competition among patrilineal kin groups could drive a sharp reduction in Y‑chromosome diversity while leaving mitochondrial lineages relatively stable. They introduce an analytical Lotka–Volterra framework and a computational grid simulation to show that when descent groups are patrilineal and compete, entire Y‑chromosome clades can be lost at accelerated rates through cultural hitchhiking and drift. Simulations reproduce two key empirical signals seen in modern datasets: a bottleneck‑like collapse in male line diversity without requiring a demographic crash, and rapid, star‑like expansions of a few dominant Y lineages. Archaeogenetic patterns from post‑Neolithic farmer and pastoralist cultures further align with the model’s expectations, showing shallow coalescence and high Y‑line homogeneity within cultural groups across large geographies.

Conclusion:
By linking social organization to genetic patterns, this work reframes the post‑Neolithic Y‑chromosome bottleneck as a cultural phenomenon, sharpening how archaeogenetic signals can be interpreted to infer past social structure and conflict dynamics.

Reference:
Zeng, T. C., Aw, A. J., & Feldman, M. W. Cultural hitchhiking and competition between patrilineal kin groups explain the post‑Neolithic Y‑chromosome bottleneck. Nature Communications, 2018; 9:20 77. https://doi.org/10.1038/s41467-018-04375-6

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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On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Chapters

• (00:00:14 ) - The genetic crash of the Neoles
• (00:02:43 ) - The genetic bottleneck of the Neolithic
• (00:09:08 ) - How patrilineal DNA helped explain human societies
• (00:14:28 ) - Base by base science podcast