Susanna Sabin wins prestigious Wenner-Gren Dissertation Fieldwork Grant
Sabin, a PhD student in the Department of Archaeogenetics, was awarded the grant for the project “Revealing the History of Human Tuberculosis with Diverse Ancient and Modern Pathogen Genomes.”
December 19, 2017
Sabin’s project looks at the question of how long tuberculosis has been an infectious disease in humans. Today, tuberculosis is one of the most deadly, omnipresent pathogens in the world, but its role in human history remains unclear. Currently, researchers have two theories. One is that tuberculosis emerged during the Neolithic as part of a broader trend in which, as humans took up farming and began living in larger, settled communities, virulent infectious diseases began to thrive. The second theory is that tuberculosis infected humans before the advent of agriculture, pre-dating the Neolithic transition, and potentially had a significant impact on the evolution of our species. This project aims to help solve this problem by sequencing ancient genomes of the Mycobacterium tuberculosis complex, the group of bacteria that cause the disease. The resulting data could then be used to help solve these questions.
Ancient genomes can act as calibration points for molecular dating techniques. The value of this calibration was seen in recent years when the first ancient tuberculosis genomes were published. The data provided from those studies suggest that the ancestor of modern tuberculosis-causing bacteria is considerably younger than indicated by prior estimates, which were based on the analysis of modern DNA. However, because different lineages within this family of bacteria mutate at different rates, more data is needed to better estimate the age of the group as a whole.
The project will look at diverse and under-utilized sources of tuberculosis DNA, such as ancient wild seals from natural and archaeological contexts, ancient European humans, and modern non-human primates, in order to generate multiple, high-quality genomes that can act as calibration points across time, space, and host for determining how old tuberculosis truly is.
Wenner-Gren Dissertation Fieldwork Grants are awarded to aid doctoral or thesis research that demonstrates a clear link to anthropological theory and debates, and promises to make a solid contribution to advancing these ideas.