Genomic impact of the second plague pandemic on three human populations

Genomic analysis of 529 ancient individuals reveals no strong positive selection from Yersinia pestis during the second plague pandemic across northern Europe.

• Why it matters: Understanding whether plague exposure drove genetic adaptation helps clarify human evolutionary responses to pandemics and their influence on migration and population structure.
• What they did: Researchers sequenced genomes from individuals in Norway, Sweden, and Lithuania, comparing pre- and post-pandemic samples at an average depth of 8.8x to detect signatures of selection.
• The result: No evidence of positive selection was found, but a significant reduction in genetic diversity and migration occurred after Y. pestis arrival, coinciding with major sociohistorical shifts like Christianisation and climate change.