A stretch of DNA inherited from our Neanderthal cousins increases people’s chances of developing a severe case of Covid-19, according to a new study in the journal Nature.
A number of factors are known to up your chances of falling seriously ill with Covid-19, from your age and lifestyle to genetics. A previous study recently revealed that a segment of DNA found on chromosome 3 was tightly linked to a higher risk of hospitalization and respiratory failure after falling ill with Covid-19.
Now, in a new study, scientists at the Max Planck Institute for Evolutionary Anthropology have discovered that this gene cluster is remarkably similar to DNA sequences found in the genome of a 50,000-year-old Neanderthal discovered in Croatia, indicating the gene variant was most likely passed on to humans through prehistoric interbreeding with Neanderthals.
The genetic variant is especially common among people in South Asia where about half of the population carry it. Around one in six people carry the risk variant In Europe, but it’s practically non-existent across Africa and East Asia. Although it appears that people who have this sliver of Neandertal DNA are at higher risk of a severe Covid-19 infection, there is no clue yet as to why the genetic variant leaves people more at risk.
“It turns out that this gene variant was inherited by modern humans from the Neanderthals when they interbred some 60,000 years ago,” Hugo Zeberg, lead author from the Max Planck Institute for Evolutionary Anthropology, said in a statement. “Today, the people who inherited this gene variant are three times more likely to need artificial ventilation if they are infected by the novel coronavirus Sars-CoV-2.”
“It is striking that the genetic heritage from the Neanderthals has such tragic consequences during the current pandemic. Why this is must now be investigated as quickly as possible,” Svante Pääbo, study author and director at the Max Planck Institute for Evolutionary Anthropology.
Modern humans, or Homo sapiens, and Neanderthals shared a common ancestor roughly half a million years ago. Once humans finally ventured out of their homeland of Africa and made it to Eurasia, they met up with Neanderthals and widely interbred with each other (along with other archaic hominins). This rampant canoodling means hints of genetic influence from other hominids can still be found in the DNA of most modern-day human populations, especially people of European and East Asian descent.
It’s been some 50,000 years since humans and Neanderthals mated, but the legacy of this intermingling can still be felt today. As one of many examples, this lingering DNA is thought to increase one's risk of allergies, addiction, and depression.