Those of us with peanut allergies know how hard it is to avoid being around peanut-containing products.
Chocolate bars, cereals, fried foods and even kissing someone who has eaten something that contains peanuts could cause an allergic reaction.
But why do people have allergies?
We know there is a reason for these types of allergies. We know why your throat closes and why it is difficult to breathe when you eat or inhale something you are allergic to and why you swell if you are stung or bitten by certain insects.
And it all started tens of thousands of years ago, when our ancestors came into contact with Neanderthals.
There is a very probable reason why people develop allergies altogether. And it boils down to the fact that our ancestors had sex with Neanderthals more than 40,000 years ago.
A 2014 study by the genetics company 23andMe believed that all non-African individuals carry between one and six percent of Neanderthal DNA, and three genes especially in this DNA may be responsible for overly sensitive immune systems that make us susceptible. to allergies.
But a 2016 study by American Journal of Human Genetics found that 2% of most people’s DNA is more likely to come from human and Neanderthal sex.
The 2014 study found that carriers of these three genes are more likely to have hay fever, asthma, and other allergies.
The researchers say the genes spread when pioneers who left Africa had sex with Neanderthals living in Eurasia. Since Neanderthals lived in this area for over 200,000 years, their immune system has adapted to any new infection.
Janet Kelso, principal investigator at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said: “A small group of modern people leaving Africa would not have much genetic variation. You can adapt through mutations, but if you cross paths with the locals who are already there, you can get some of these adaptations for free. “
Researchers analyzed the genome of modern humans to see if Neanderthal DNA was present; then they looked at the community of people around the world.
They found that two out of three genes in the immune system closely match this DNA.
The 2016 study found that in addition to giving you allergies, the Neanderthal part of your DNA can actually help you fight disease.
Geneticists believe that there is a group of genes in our DNA that we inherited from Neanderthals, which is the first line of defense against dangerous pathogens that enter our body, provided that these genes also affect people’s allergies.
Janet Kelso, a researcher at the Max Planck Institute for Evolutionary Anthropology, said: “Increased resistance to bacterial infection has been beneficial, but may result in increased sensitivity to non-pathogenic allergens.”
These genes establish an innate immune response to pathogens that invade our bodies.
The innate immune response is our body’s first line of defense against disease. It can usually destroy pathogens before we realize we are really sick.
Since Neanderthals introduced this response into human DNA, it has survived so long because of natural selection and the idea of survival of the fittest.
So, those who are not killed by the disease, those who have an innate immune response are able to procreate and transmit genes. Therefore, we are still seeing the resurgence of Neanderthal genes in modern humans.
If you have developed allergies in your lifetime, you have ancestors who will thank you for it.
Editor’s note: this article was originally posted in January 2016 and has been updated with the latest information
Samantha Maffucci is the editor of YourTango, who has written hundreds of articles on relationships, news and entertainment, and astrology. Access her author profile for more content.