The Neanderthals were smart, tough, and well-adapted to the cold where they lived in regions north of Africa, so what happened to them?
Some scientists have argued that when modern humans left Africa, they interbred with Neanderthals. Others have argued that modern humans wiped out Neanderthals by out competing them for resources and by waging war.
Here's a strange theory: Neanderthals died out because they lacked skills in clothing design.
Neanderthals disappeared about 35 thousand years ago. That's just before the last glacial maximum. Now, because Neanderthals had evolved to live in cool northern climates, they'd had no need to invent tools that would allow them to make complex, multi-layered clothing. So when things suddenly got really cold, they were caught with their pants down, so to speak.
However, modern humans were more vulnerable to the cold. Those living in cooler parts of Northern Africa had long before the glacial maximum developed tools like needles and stone blades for sewing warmer, multi-layered clothes, including undergarments. When the maximum hit, modern humans were better able to stay warm.