Sunday, December 9, 2018

A 5,000-year-old Mass Grave Harbors Oldest Plague Bacteria Ever Found

mass grave

This article highlights the importance of a Scandinavian woman who was buried in a mass grave around 5,000 years ago, and was found nearly 20 years ago in Sweden. Bacterial DNA that was extracted from the woman's teeth shows that she is the earliest known case of the plague in humans. The bacteria found comes from an ancient strain of Yersinia pestis, which causes the plaque. A man in the same mass grave has shown the same traces of the plague, but they were not as well preserved as the woman's.  This discovery suggests that a plague epidemic started "more than 5,000 years ago in densely populated farming communities in southeastern Europe" (Bower).  While previously it was believed that the Y. pestis strain of the plague could've come from Yamnaya herders from Asia into Europe, based on the timeline speculated, this discovery has proven that this strain was already in Europe before the herders came.

It is amazing to me that we can use DNA of humans from 5,000 or more years ago to discover information like this. This shows the importance of genetics in human history and how it can be used to formulate timelines of important events of the past, such as the plague. Overall, I'm shocked by these findings and find them to be very important to the modern world, in order to further our understanding of the past.


Bower, Bruce. “A 5,000-Year-Old Mass Grave Harbors the Oldest Plague Bacteria Ever Found.” Science News, Society for Science & the Public, 7 Dec. 2018,

“Studies Reveal Howplague Disables Immune System and How to Exploit the Process to Make a Vaccine.” UChicago Medicine - At The Forefront, UChicago Medicine, 27 July 2005,


  1. This is super interesting, I also find it amazing that DNA from fossils can tell us so much about the time period and human livelihood in an era where we have no information at all. I also agree that this specifically can demonstrate the importance of genetics and the way is is across multi-disciplines.

  2. Another interesting benefit we can derive from this is observing the past organisms and bacteria such as the Y. pestis. Getting information on the past micro organisms may help discover unknown things of bacteria today.