The Black Death was the single greatest mortality event in recorded history, killing up to 50% of the European population in less than five years. New research from the University of Chicago, McMaster University, and the Institut Pasteur has found evidence that one of the darkest periods in recorded human history placed a significant selective pressure on the human population, changing the frequency of certain immune-related genetic variants and affecting our susceptibility to disease today. The results were published on October 19 in Nature.
Caused by the bacterium Yersinia pestis, the global pandemic of the bubonic plague wiped out 30% to 60% of people in cities across North Africa, Europe, and Asia, with massive repercussions for the human race — and, apparently, our genome.
“This was a very direct way to evaluate the impact that a single pathogen had on human evolution,” said Luis Barreiro, professor of genetic medicine at UChicago and co-senior author on the study. “People have speculated for a long time that the Black Death might be a strong cause of selection, but it’s hard to demonstrate that when looking at modern populations, because humans had to face many other selective pressures between then and now. The only way to address the question is to narrow the time window we’re looking at.” Read More
Citation: “Evolution of immune genes is associated with the Black Death.” Nature, Oct. 19, 2022.
Funding: National Institutes of Health, the Wenner-Gren Foundation, the UChicago DDRCC, Center for Interdisciplinary Study of Inflammatory Intestinal Disorders (C-IID), Insight Grant.
—Adapted from an article first published by University of Chicago Medicine.
Etching by L. Sabatelli of the plague of Florence in 1348. A new study examined ancient DNA samples from the bones of over 200 individuals from London and Denmark who died before, during, and after the Black Death plague swept through the region in the late 1340s. Image courtesy of Wellcome Library, London.
Using DNA extracted from teeth of people who died before, during and after the Black Death pandemic, researchers were able to identify genetic differences that dictated who survived and who died from the virus. Photo by Matt Clarke/McMaster University