A recent bottleneck of Y chromosome diversity coincides with a global change in culture
Level 4 - case-series / case-control
By design analogy (observational population genomics and phylogenetic modeling)
OpenAlex W2140276652 · doi:10.1101/gr.186684.114
What was done
The authors analyzed 456 geographically diverse, high-coverage human Y-chromosome sequences, including 299 newly reported samples. Using ancient DNA calibration, they estimated divergence times for global male lineages and compared the reconstructed demographic history to female lineage patterns based on mitochondrial DNA (mtDNA).
What was found
The Y-chromosomal most recent common ancestor (MRCA) in Africa was dated to 254 kya (95% CI 192–307 kya). A cluster of major non-African founder haplogroups was identified in a narrow window of 47–52 kya. In contrast to mtDNA reconstructions, the authors identified a second strong bottleneck in Y-chromosome lineages occurring within the last 10 kya.
Why it matters
This study demonstrates a major Holocene reduction in male genetic diversity that did not affect female lineages, providing genetic evidence that changes in human culture and social structure likely altered the variance in male reproductive success.
Limits
The cultural explanation for the Holocene bottleneck is an inferential hypothesis rather than directly measured historical data. In addition, lineage dating depends on molecular clock calibrations and mutation rate assumptions, and a sample size of 456 genomes provides limited coverage of smaller or underrepresented global populations.
Cited by
- context Historically across human evolutionary history, only approximately 40% of men have reproduced, compared to 80% of women.