Researchers Mapped Centuries of Plague Evolution
A new genetic analysis identifies how Yersinia pestis persisted in Europe and Russia through the 18th century.
Updated on Sept. 29, 2026 in Life Sciences
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Researchers reconstructed 26 Yersinia pestis genomes from archaeological sites to track the bacteria's evolution from the 14th century through the 18th century. The study, published in PNAS, confirms how distinct lineages drove repeated outbreaks across Europe and Russia.
Why it matters
Understanding this long-term pandemic path provides insight into how disease reservoirs stabilize in wild rodent populations. The data suggests that environmental shifts, such as the Great Renaissance Drought, likely forced rodents closer to human settlements.
The study utilized 26 reconstructed Y. pestis genomes compared against a total database of 75 dated plague genomes. Researchers successfully linked these sequences to historical fatality records using radiocarbon dating.
The players
PNAS
A multidisciplinary scientific journal that publishes high-impact research across the biological, physical, and social sciences.
The details
The team matched plague genomes to historical outbreaks by constructing a family tree of Yersinia pestis, the causative agent of plague. By combining radiocarbon dating — a method for determining age by measuring the decay of carbon isotopes — with historical archives, they mapped how lineages diversified significantly between 1450 and 1500. This genetic shift potentially established new disease reservoirs in rodents that fueled outbreaks for centuries.
Timeline
1347-1353: First wave of Black Death in Europe.
1450-1500: Major diversification occurred in Yersinia pestis lineages.
1618-1648: Plague outbreaks coincided with the Thirty Years' War.
1700-1721: Plague outbreaks coincided with the Great Northern War.
18th century: The centuries-long plague pandemic concluded.
The Tech Race
This study aligns with the broader push in ancient pathogen genomics to map how bacteria persist in dormant environmental reservoirs. It follows a pattern established by recent efforts to define the lineage trees of historical plague samples across Eurasia.
This research provides historians and epidemiologists with a more precise timeline for historical mortality events across Europe and Russia. As further ancient DNA is recovered, the researchers expect to increase the resolution of the Y. pestis lineage tree.
The takeaway
This analysis confirms that plague persistence was tied to major lineage diversification and climate-driven shifts in rodent habitats. Future efforts will focus on recovering additional ancient DNA to resolve the precise geographical origins of these recurrent plague reservoirs.
Further reading
For more on how researchers are mapping ancestral pathogens, see Life Sciences.
Source note: This article includes information reported by ScienceAlert.
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