What's Happening?
A recent study has uncovered the earliest known genetic evidence of the plague bacterium, Yersinia pestis, in East Asia, suggesting that plague lineages spread rapidly across Eurasia around 5,300 years ago. The genome was recovered from an individual
buried at the Middle Neolithic cemetery of Zhengjiagou in northern China, dated to approximately 5,465–5,074 years ago. Additionally, two plague genomes were identified from Early Bronze Age burials in the Minusinsk Basin of southern Siberia, dated to around 4,500–4,200 years ago. The study involved screening 1,400 ancient human remains from eastern Eurasia and revealed a major early diversification event connecting closely related strains found in northern China, Germany, and southern Scandinavia. The findings indicate that these strains separated within a period of roughly 200 years, despite being distributed across more than 7,500 kilometers.
Why It's Important?
This discovery extends the prehistoric record of plague into East Asia, indicating that the pathogen had already achieved a continent-wide distribution thousands of years before historically documented pandemics. The study provides insights into the early evolution of plague, showing that the Chinese and Siberian strains lacked the ymt gene, which later became important for efficient flea-borne transmission. Understanding the early spread and evolution of plague can help researchers better comprehend the dynamics of ancient pandemics and the factors that contributed to their spread. This knowledge is crucial for modern epidemiology and can inform strategies to prevent and manage future outbreaks.
What's Next?
Further research is needed to clarify the routes, hosts, and transmission mechanisms involved in the early expansion of plague. Additional ancient genomes from East Asia and other regions will be essential to provide a more comprehensive understanding of the spread and evolution of the disease. Researchers will continue to explore the genetic evidence to uncover more details about the early diversification and distribution of plague lineages.
