If your eyes are watery and you can’t stop sneezing whenever you drive by a hayfield or go for a stroll in the woods, you might have Encino Man to thank. (Well, Neanderthal genes, anyway.)
[ photo source ]
Although scientists used to think Neanderthals didn’t have much in common with modern humans, they came to realize they were more sophisticated than they thought. Two new studies have shown that people with Neanderthal genes in their DNA are predisposed to common allergies like hayfever.
Neanderthals had been living in Eurasia — the combined continental landmass of Europe and Asia — for 200,000 years when early Homo Sapiens passed through and they sometimes mated (well, er, “interbred”). These modern humans then carried some of the Neanderthal DNA with them as they migrated further.
Scientists searched through human DNA samples (collected by the 1,000 Genomes Project, an international research effort to establish a catalogue of human genetic variation) looking for genes from Neanderthals — as well as another kind of early human called the Denisovans.
The results? They identified three genes (from these extinct groups) that play a role in controlling our immune system. These genes mobilize key immune system cells to attack when the body detects a foreign substance, and it’s what would have helped these early humans survive the crazy new threats and diseases they were encountering. Modern humans retained the genes that would allow them to adapt to local pathogens, so it was a good thing!
Well … until now? For people who still carry those Neanderthal genes today, they’re going to experience the opposite effect — an overreaction to certain stimuli, like pollen and animal dander — and be more likely to develop allergies.
Of course, it’s also possible that those lingering genes are protecting people from other pathogens. Scientists call that “the $1 million question,” and no one is sure yet.