As I described in my last post, the Initiative for the Science of the Human Past at Harvard allowed me to develop my thesis question concerning the gap in the historical record for when we know fully-virulent plague to have existed in human populations and when we first see any evidence for a major pandemic. There are two components to my question, cultural and genetic.
The cultural component consists of a literature review of three populations–the Srubnaya (19th c. BC), EIA Armenia (9th c. BC), and Constantinople (6th C. AD). All three of these populations have genetic evidence for plague infections, but only Constantinople shows any evidence for a fully fledged epidemic (the Justinianic Plague). By investigating the different cultural behaviors of these populations, I’m working to understand what could have played a role in limiting the pathogenicity of plague for the Srubnaya and EIA Armenia, who didn’t appear to suffer from an epidemic as Constantinople did despite the presence of plague in the population.
The genetics component of my thesis involves screening 330 deep shotgun sequenced genomes from ancient Europeans to investigate the presence of any of eleven “common” European genetic diseases, to see if the appearance and spread of those mutations correlates at all with the spread of plague throughout Europe.
While working on my research throughout the fall, I was offered the chance to spend a month at the Max Planck Institute for the Science of Human History, the partner organization for the MHAAM project. This was an unbelievable opportunity for someone working on my research question because the Archaeogenetics group of the Institute has published many of the most significant genetic findings on Yersinia pestis in the last few years, including the papers that allowed me to determine the three cultural populations I intended to compare for the cultural review.
Since arriving at the Max Planck Institute in Jena, Germany three weeks ago, I’ve had the opportunity to not only discuss my research processes with leading scientists in the field but also observe the data collection and analyses of a leading aDNA laboratory. Through my discussions, I’ve gained further insight on the leading theories for differential observed virulence in specific populations and the cultural factors are frequently at play. I’ve learned about new analysis tools that could hypothetically be applied to my data (such as MALT) and geographic models that will benefit the presentation of my work.
I’ve spent a few days in the lab itself–all suited up to avoid contaminating the ancient DNA samples!–and observed the process of drilling and sampling dental pulp in an attempt to retrieve DNA.
My time in Jena has given me significant additional context on my research. My ideas and analysis are substantially more developed thanks to the feedback and suggestions I’ve received from the experts in this field. I have a lot more appreciation for the labor-intensive process required to sample aDNA and the myriad of techniques required to assemble the data and account for the complexities of degraded samples. I have also seen the passion with which people enter this rapidly growing field to investigate questions we could not have imagined being able to answer before modern genetic technology. I am excited to be making my own small contribution to this-ever growing field, and I’m honored to have had the opportunity to see the work that’s redefining human history firsthand.