Scientists have discovered evidence of plague outbreaks in Siberia dating back 5,500 years, pushing back the known timeline of the disease by millennia. The findings, based on analysis of ancient settlements, reveal a previously unknown strain of the bacterium *Yersinia pestis*, the causative agent of plague. This discovery suggests the plague impacted hunter-gatherer populations much earlier than previously believed, challenging existing understandings of its spread. Researchers identified genetic markers within the remains, confirming the presence of the plague bacterium. The study also offers insights into potential transmission routes, suggesting infection may have occurred through contact with infected marmots and other wild animals. This research provides crucial data for understanding the evolution and historical impact of this devastating disease.