Lecture on history, genetics, and infectious disease

Here is the video of a lecture I gave in October of 2016 titled “Nature Did It: Romans, Ecology, and the Global History of Infectious Disease.” The lecture was sponsored by the Initiative for the Science of the Human Past at Harvard University.

In AD 165, the Roman Empire and its neighbors were struck by what was perhaps the most lethal disease event in human history up to that time: the Antonine Plague. Converging evidence suggests that the pathogenic agent of the mortality was smallpox, Variola major, one of the great killers in human history down to its eradication in the 1970s. As historians, we have long had written and archaeological sources to help us piece together the outlines of this historical event. Now, whole genome sequencing is letting us work with natural scientists to use genes as a kind of historical archive. We have learned that the closest evolutionary relative of smallpox (an Orthopoxvirus) is Taterapoxvirus, which infects the naked-sole gerbil, a rodent of the African dry forests. Thus, smallpox probably evolved in Africa, only 2-4 thousand years ago (Babkin and Babkina 2015).


In this lecture, bringing together traditional and novel sources of evidence, I argue that smallpox was an emerging infectious disease that entered the Roman Empire across trade routes connecting the Roman world to East Africa. During the Roman Empire, trade (in spices, gold, ivory, slaves, silk, and so on) across the Red Sea and into the Indian Ocean world connected the Romans to a much broader world.


The deeper point is that human social development has reshaped the ecological and evolutionary context of microbial pathogens and that the humanities and natural sciences can partner to deepen our understanding of the role of infectious disease in human history.

Here’s the video. My lecture starts at 11:00 in.