My work uses an evolutionary framework informed by ancient DNA (aDNA), historical, bioarchaeological, and archaeological methods to explore the processes that shape patterns of health and disease in the past. This approach can provide a “deep time” window into the biological consequences of changing social, cultural and ecological circumstances on health outcomes.
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 previous postdoctoral work at Penn State focused on temporal patterns in ‘predicted’ genetic contributions to height and ‘actual’ skeletal height before, during, and after the subsistence shift to agriculture in Europe (~12,000 BP to 2,000 BP).
The shift to farming broadly caused a decline in health among early farmers (i.e., shorter in stature than hunter-gatherers, more skeletal stress), although this isn’t a universal trend. I looked at both the genetic and skeletal aspects of height to identify whether individuals were relatively taller or shorter than expected as ways of life were changing from hunting and gathering (foraging) to agricultural strategies (i.e., plant and animal domestication). I also explored whether stress experienced in childhood (using skeletal indicators) is also impacting an individual’s achieved (skeletal) height during the foraging-to-farming transition.
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.