Denisovans: Ancient Allies in Our Fight Against Germs

Denisovans, long-gone relatives of modern humans, left a lasting mark on our DNA. Their genes are still present in people from East and Southeast Asia. But how did the places they lived shape our ability to fight off diseases? That's the question scientists set out to answer. They looked at three spots where Denisovans once lived. These places had cold winters and warm summers. The researchers checked if these areas were home to certain germs and the creatures that spread them. They found that Denisovans lived in areas where some diseases, like those spread by mosquitoes, were rare. But other illnesses, like Lyme disease, were common. Interestingly, people in Melanesia today have a lot of Denisovan genes. But they don't have the ticks that spread Lyme disease. This suggests that Denisovans might have given us genes to fight off other diseases, like those spread by mosquitoes. The study also found that one Denisovan site, Cobra Cave in Laos, was suitable for many diseases. This could mean that Denisovans living there had to deal with a lot of different germs. Their genes might have helped them—and now us—survive in these tough environments. But there's a catch. The study only looked at a few diseases and places. There's still a lot we don't know about how Denisovans shaped our ability to fight off germs. Still, it's a fascinating glimpse into our past and how it affects our health today.