Yersinia pestis, the etiologic agent of plague, is a bacterium associated with wild rodents and their ﬂeas. Historically it was responsible for three pandemics: the Plague of Justinian in the 6th century AD, which persisted until the 8th century; the renowned Black Death of the 14th century,with recurrent outbreaks until the 18th century; and the most recent 19th century pandemic, in which Y. pestis spread worldwide and became endemic in several regions. The discovery of molecular signatures of Y. pestis in prehistoric Eurasian individuals and two genomes from Southern Siberia suggest that Y. pestis caused some form of disease in humans prior to the ﬁrst historically documented pandemic. Here, we present six new European Y. pestis genomes spanning the Late Neolithic to the Bronze Age (LNBA; 4,800 to 3,700 calibrated years before present). This time period is characterized by major transformative cultural and social changes that led to cross-European networks of contact and exchange. We show that all known LNBA strains form a single putatively extinct clade in the Y. pestis phylogeny. Interpreting our data within the context of recent ancient human genomic evidence that suggests an increase in human mobility during the LNBA, we propose a possible scenario for the early spread of Y. pestis: the pathogen may have entered Europe from Central Eurasia following an expansion of people from the steppe, persisted within Europe until the mid-Bronze Age, and moved back toward Central Eurasia in parallel with human populations.I now think that many of the biggest changes in history were caused by the interaction of conquest with disease. We speak Indo-European languages because one wave of invaders from the steppes brought with them a Plague to which the natives had no resistance, allowing the invaders to completely dominate the societies that emerged afterwards. Less than 2% of the people in North America are Native, and even most of them have some European or African genes, because they were horribly vulnerable to Old World diseases. But in central Africa European conquest left almost no genetic imprint, because it was the Europeans who were vulnerable to African diseases rather than the other way around.
Saturday, May 2, 2020
Update on the Science of Yersinia Pestis in the Bronze Age
New article in Current Biology Report by Aida Andrades Valtueña and many others, which I got off Academia: