My work uses an evolutionary framework informed by ancient DNA (aDNA), historical, osteological, and archaeological methods to explore the processes that shape patterns of health and disease in the past. This type of approach can provide a window to understand how we have evolved and adapted to changing social, biological and ecological environments.
Current postdoctoral project: A multi-proxy biomolecular and skeletal investigation of stature across the agricultural transition
Ancient genomes provide unique time-stamped perspectives of the emergence and trajectory of adaptive responses to specific ecological or demographic events. My postdoctoral work at Penn State focuses on temporal patterns in ‘predicted’ genetic versus ‘actual’ osteological height variation before, during, and after the subsistence shift to agriculture from the Upper Paleolithic to the Iron Age in Europe (~12,000 BP to 2,000 BP).
So, I am quantifying osteological and genetic height on a per-individual basis, to identify whether individuals were relatively taller or shorter than expected across various time points before, during and after the shift to sedentary farming lifestyles. I am also exploring whether the pattern of differences between osteological and genetic height are explained in part by the presence/absence of skeletal indicators of early childhood stress, since these can impact an individual’s growth trajectory.
Malaria in Imperial period Italy (1st-4th c. CE)
The history of malaria in ancient Italy is particularly fascinating. The causative species of malaria are “invisible” in the historical record, while malaria as a disease is indirectly supported by evidence from literary works (e.g., Celsus’ De Medicina) and non-specific skeletal responses. I worked on Imperial period assemblages in southern Italy (1st-4th c. CE) when malaria was presumed to be at its peak. Ultimately, I identified the presence of Plasmodium falciparum (considered the most virulent species today) in two locations where malaria was unexpected – a minor suburban city (Velia) and rural hinterland (Vagnari), rather than the metropolis of Portus Romae, which was historically in the “malaria belt”. The take-away from this work is that ancient DNA is a complementary approach to reconstruct complex human-parasite interactions in dynamic environments (Marciniak et al., 2018).
Detection and characterization of pathogens in the past
I am working on a molecular screening strategy to identify over 1,000 pathogens all at once in archaeological human remains, providing an approach to prioritize contextually relevant pathogens in scenarios where multiple lines of evidence (e.g., skeletal, archaeological, or historical) do not suggest a consensus. Ideally, such a pathogen screening strategy will enhance the discovery of pathogens from diverse human archaeological assemblages by providing a quantitative assessment on the pathogens that were likely present at different places and times in the past. There has been a dramatic increase in the types of pathogens recovered (shown below, from Marciniak & Poinar, 2019), so being able to further improve the characterization of such diversity would greatly inform interpretations about health and disease in the past.