Because most of us brush our pearly whites at least twice a day, we rarely think of them as time capsules for the stuff we’ve put in our mouths.
But, as the hardest parts of our bodies (thanks to the calcified material called dentine, which makes teeth distinct from the rest of our bones), teeth tend to stick around the longest after the rest of us is gone. Which makes them perfect specimens for paleontologists studying our Neanderthal ancestors, who roamed around roughly 45,000 to 50,000 years ago, and didn’t have the degree of dental hygiene we do today.
In a new study published March 8 in Nature, a global collaboration of researchers from Europe, the UK, Australia, and South Africa reported that they had analyzed the plaque from the dental remains of five Neanderthals who lived in what is now Spain and Belgium. The team found almost the entire genetic blueprint for a single-cell organism called Methanobrevibacter oralis, which to this day likes to live between our teeth and jump from person to person when we share saliva.
“If you’re swapping spit between species, there’s kissing going on, or at least food sharing,” Laura Weyrich, palaeomicrobiologist at the University of Adelaide in Australia who co-wrote the study, told Nature.
The evidence that Neanderthals were taking trips to smooch town suggests their interactions were a lot friendlier than we usually think of them. These hominids were frequently in close contact as they cared for one another, which challenges the popular idea of Neanderthals as mere caveman. “These were sophisticated relatives of ours,” Keith Dobney, a paleontologist at the University of Liverpool in the UK, told the Verge.
In addition to the M. oralis, the research team found genetic evidence of poplar plants, which contain a chemical used in modern-day aspirin, and mushrooms, moss, pine nuts, woolly rhinoceros, and sheep meat—the original paleo diet, you might say. No doubt a smoothie of those will be soon be available at trendy juice shops for no less than $20.