Christina Warinner | Cell: Bronze Age Yersinia pestis genome from sheep sheds light on hosts and evolution of a prehistoric plague lineage
The Department of Anthropology at Harvard University is excited to share a major article just today released in Cell. Presenting research from Professor Christina Warinner alongside an international team of researchers from the Max Planck Institute of Infection Biology, Harvard University, the University of Arkansas, Max Planck Institute of Evolutionary Anthropology, and Seoul National University, the article explores an ancient Yersinia pestis genome recovered from sheep sheds new light on a mysterious infectious disease that plagued prehistoric Eurasia for over 2000 years.
Warinner and researchers investigated the bones and teeth of Bronze Age livestock at the pastoralist site Arkaim (Russia), a Eurasian Steppe site belonging to the Sintashta-Petrovka culture known for its innovations in cattle, sheep, and horse husbandry. There they identified a 4,000-year-old sheep infected with the same LNBA lineage of Y. pestis that was infecting people at the time. This study reveals the connections between domesticated animals and the spread of one of the world's most infamous bacteria, providing insight into how the pathogen was so successful in infecting people across thousands of kilometers over thousands of years.
Summary:
Most human pathogens are of zoonotic origin. Many emerged during prehistory, coinciding with domestication providing more opportunities for spillover into human populations. However, we lack direct DNA evidence linking animal and human infections during prehistory. Here, we present a Yersinia pestis genome recovered from a 3rd-millennium BCE domesticated sheep from the Eurasian Steppe belonging to the Late Neolithic Bronze Age (LNBA) lineage, until now exclusively identified in ancient humans across Eurasia. We show that this ancient lineage underwent ancestral gene decay paralleling extant lineages, but evolved under distinct selective pressures, contributing to its lack of geographic differentiation. We collect evidence supporting a scenario where the LNBA lineage, unable to efficiently transmit via fleas, spread from an unidentified reservoir to sheep and likely other domesticates, elevating human infection risk. Collectively, our results connect prehistoric livestock with infectious disease in humans and showcase the power of moving paleomicrobiology into the zooarchaeological record.