The bubonic plague, known colloquially as the Black Death and scientifically as Yersinia pestis, for almost 700 years has intrigued and figuratively plagued the academic community. Accounting for the death of almost 1/3 of the British population in the 14th century, it remains as one of the most monumental infectious diseases in history. Its been reported as early as the 6th century A.D. in the Mediterranean, and as late as the 20th century (Wade 2010). The question is, has it been studied to death, or can we learn more?
Do not fret, Black Death studies not only live on, but have been upgraded! DNA studies and world history are integrating perspectives to shine new light on the disease.The new narrative being formed follows the spread of the disease along the Silk Road. Historians are noting the events and routes in history indicative of the infectious disease, while Geneticists track DNA and protein markers of Yersinia pestis in skeletal remains recovered from plague pits (Morelli et al. 2010). This study by Morelli et al. reduced the disease to single nucleotides in the genome, and tracked each against historical routes. These include the 2.MED cluster which is tracked from East China to Kurdistan, whose route was likely along the Silk Road. It is this type which spread across the Caucasus mountains and into Europe. Another is the movement from China to Africa from cluster 1.ANT which is associated with the Zheng He expeditions in the early 15th century.
So why do we archaeologists need to worry about the DNA trail of the bubonic plague? This presents an amazing testable hypothesis for mortuary and bioarchaeological studies. Based on this article we can make predictions of possible locations for plague pits. By knowing the directions that the plague went in, archaeologists can begin to fill in the ‘human’ blanks such as how many were effected, the cultural changes that accompanied this, and the true nature of the plague. As I discussed earlier (Black Death- Not a snapshot of a population), we still don’t completely know the nature of the plague in the 14th century. By finding more plague pits, we can begin to have a better understanding of not just the nature of the virus (what environments is thrives in, who it targeted, etc), but also whether or not it changed as it spread across Eurasia. I feel a GIS project coming on…
What is most impressive about the article is this application of history to genetics. While the article could have focused on the DNA, it used history to begin to explain the spatial distribution of DNA. It is this type of innovative combination of humanities and technology that needs to be applauded. While the article does have its problems, such as sampling and lack of explicit bridging arguments, it is still an exemplar of multidisciplinary research.
Ahlstrom. 2010. Historic Spread of plague mapped through DNA. Irish Times. http://www.irishtimes.com/newspaper/ireland/2010/1101/1224282401396.html
Wade. 2010. Europe’s plague came from China. New York Times. http://www.nytimes.com/2010/11/01/health/01plague.html?_r=2
Morelli et al. 2010. Yersinia pestis genome sequencing identifies patterns of global phylogenetic diversity. Nature Genetics (Advance Online Publication, Oct. 31, 2010).