How the Bubonic Plague Changed Human Beings
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But what about the survivors of what remains the single greatest mortality event ever recorded? New research published Wednesday in the journal Nature suggests it was more than luck that determined who lived and who died.Analysis of centuries-old DNA from both victims and survivors of the Black Death has identified key genetic differences that helped people survive the plague, according to a study published in the journal Nature.
These genetic differences continue to shape human immune systems today, with genes that once conferred protection against the plague now linked to a greater vulnerability to autoimmune diseases such as Crohn’s and rheumatoid arthritis, the study said.
“We are the descendants of those that survived past pandemics … and understanding the evolutionary mechanisms that contributed to our survival is not only important from a scientific viewpoint, but can also inform on the mechanisms and genetic determinants of present-day susceptibility to disease,” said study coauthor Luis Barreiro, a professor of genetic medicine at University of Chicago, via email.
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The downside to the variant is that it has been linked to a greater susceptibility to autoimmune disorders, such as Crohn’s disease, where the immune system becomes overactive.“This suggests that populations that survived the Black Death paida price, which is to have an immune system that increases our susceptibility to react against ourselves,” Barreiro said.
He said that it was unlikely that Covid-19 outbreak would shape our immune system in a similar way — largely because the disease predominantly kills people after their reproductive age, meaning it’s unlikely genes that confer protection would be passed on to the next generation.
It’s tempting to wonder what Covid-19 will do here, but it’s also worth noting that in the global history of disease, Covid is a fairly minor blip. It’s not insignificant, but it’s most certainly nothing at the level of what bubonic plague did in Europe and western Asia. And nearly a thousand years later, it’s unlikely that Covid will have changed the way bodies respond to disease to this extent, though Covid will probably still be part of our world in 3000 if humans still exist.