Figuring out how to ignite fire has long been considered one of humankind's most monumental achievements. While pop culture often depicts our ancestors rubbing two sticks together in caves, new findings suggest that Neanderthals were using a smart chemistry hack to fuel their fires 50,000 years ago, as ZME Science reports.

In a paper recently published in Scientific Reports, a team of Dutch scientists shared their analysis of small chunks of manganese oxides they discovered in the Pech-de-l’Azé I cave in southwest France. Such black "blocs" were believed to have been primarily used as pigments in cave drawings and body paintings, but further investigation shows that this use may have been secondary for Neanderthals.

The research team conducted a series of experiments on the effects of manganese dioxide when starting fires. They found that the chemical compound, which is abundant in nature, can be used to lower the auto-ignition temperature of wood and increase the rate of char combustion. This would have made starting a fire much easier for early humans. Evidence of Neanderthals grinding these blocs into powder further suggests that they were using it as fuel.

Until recently, many experts believed that Neanderthals died out because they weren't as cognitively advanced as their Homo sapiens counterparts. Using chemistry to start fires would have required some sophisticated thinking on their part, which could mean Neanderthals were much craftier than originally thought.

[h/t ZME Science]