Black Death Did Not Lead to Genetic Shift in Cambridgeshire
The Black Death spread across Europe, North Africa and Asia, killing large populations of people.
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The Black Death was a bubonic plague that killed at least 25 million people. Caused by the bacterium Yersinia pesti (Y. pesti), the plague spread across Europe, killing ~65% of people in certain European populations.
Researchers from the University of Cambridge investigated whether the pandemic led to a genetic shift in disease susceptibility in the surviving populations. Their study is published in Science Advances.
Shifting population genetics
Ancient DNA (aDNA) analysis is helping scientists understand how migration events, population shifts and the impact of historical diseases have shaped the world that we live in today.
The Black Death spread across Europe, North Africa and Asia, killing large populations of people. The massive loss of life has led many researchers to question whether the pandemic could have caused an evolutionary change in genetic variation in certain areas.
Previous studies have linked the Black Death to a shift in immune genes, resulting in an increased susceptibility to certain autoimmune diseases. Lead author, Dr. Ruoyun Hui research fellow at The Alan Turing Institute, and colleagues used several aDNA techniques to investigate whether these findings might be replicated in Cambridgeshire populations.
Cambridgeshire, situated in the southeastern part of England, boasts a population exceeding 850,000. Renowned for housing the University of Cambridge, it is also home to one of the earliest-known Neolithic permanent settlements in the United Kingdom.
Little evidence supporting genetic shifts
Hui and team analyzed the genomes of 275 people that were living in Cambridgeshire from ~1000 to 1850 CE – before and after the Black Death. DNA was extracted from skeletal samples that had been excavated from a range of burial sites, meaning Hui and team could compare DNA from individuals who represented the different pillars of Cambridgeshire society at the time – including those buried in friaries, a hospital, urban and rural parishes and mass pits.
The results offer new insights into the social dynamics of the communities living in Cambridgeshire pre- and post-pandemic. The researchers found a lack of close relatives among the friars and the inmates of the hospital, compared to their abundance in the individuals from the general urban and rural areas. Hui and colleagues also noted long-term shifts in local genetic ancestry caused by migration from the Netherlands, Norway and Denmark.
In contrast to previous research, Hui and colleagues did not find substantial evidence to suggest the Black Death shaped the genetic makeup of surviving individuals. Although the medieval pandemic had a devasting impact on the Cambridgeshire population at the time, its genetic consequence appears to have been limited.
“These results do not mean that plague had no selective impact on genetic variation in Cambridge,” the researchers write rather the immune response to Y. pestis could involve several molecular pathways that are “yet to be fully understood.”
Reference: Hui R, Scheib CL, D’Atanasio E, et al. Genetic history of Cambridgeshire before and after the Black Death. Sci Adv. 2024;10(3):eadi5903. doi: 10.1126/sciadv.adi5903
This article is a rework of a press release issued by the American Association for the Advancement of Science (AAAS). Material has been edited for length and content.