A study using DNA from individuals between 18,000 and 200 years ago challenges the idea that modern allergies are an inevitable consequence of our genetic heritage. Researchers identified genetic variants that spread over the last 10,000 years, showing that evolution fine-tuned the immune system in distinct, non-unidirectional ways.
Genomic analysis reveals a more complex immune evolution than expected 🧬
By comparing ancient genomes with modern data, scientists found that some variants that helped fight infections like tuberculosis or the flu do increase the risk of autoimmune diseases. However, many other variants linked to immunity reduce the risk of asthma and allergies. This indicates that it is not all a trade-off between protection against infections and allergies; natural selection acted in a more nuanced way, offering protection on some fronts and risk on others.
Spoiler: your pollen allergy is not the fault of your caveman ancestors 🌿
So, according to the genes, it turns out your ancestors did not condemn you to sneeze every spring for having spent their lives in dirt-filled caves. Some even left you genes that should protect you. But of course, evolution did not foresee that you would spend 8 hours a day in front of a screen breathing air conditioning. So, if you sneeze, it is not the Neanderthal's fault: it is because of your modern lifestyle and your mold poster in the bathroom.