A Laotian cave might be a new key to uncovering hidden parts of human evolution! There, researchers found a child’s tooth that’s at least 130,000 years old. That human might be a very old relative to Homo sapiens.
New Human Species Found In The Laotian Cave
Scientists argue that one more branch of humanity had existed in the past – and the Laotian cave discovery is proving that theory. Denisovans, a now-extinct human type, used to live in the warm tropics of southeast Asia. There wasn’t much information on the Neanderthals’ cousins before researchers found a child’s 130,000-year-old tooth. Back in 2010, scientists found the first proof of existence, a finger bone of a girl. Surprisingly enough, it didn’t belong to any known human branch. Then, a wisdom tooth joined the research program. After finding both in the Denisova Cave, scientists extracted a whole new genome of a group! In 2019, there was another exciting discovery. On the Tibetan Plateau, researchers stumbled upon a whole jawbone of the species. That means they lived in China, too.
“Teeth are like a little black box of the life of the individual,” said Clément Zanolli, the study’s co-lead author and a paleoanthropologist at the France’s University of Bordeaux. Of course, there are some gene traces of Denisovans in human DNA right now. Some people from southeast Asia and Oceania have the Denisovan remnants as a result of interbreeding with Homo sapiens. “These populations’ modern ancestors were ‘mixed’ with Denisovans in southeast Asia,” Zanolli added. 2018 marks the first Asian continent discovery related to Denisovans – the area in the mountain next to Tam Pa Ling Cave.
Proof In A Child’s Tooth
A child’s tooth got the title of the first Asian continent discovery. Interestingly, it had a “typically human” shape, according to Zanolli. After studying it enough, scientists realized that the piece belonged to a female child between 3.5 and 8.5 years old. Unfortunately, it’s too old for carbon dating. Heat and humidity also ruined the possibility of identifying the DNA properly, said paleoanthropologist and study co-author Fabrice Demeter. Yet, the shape of the tooth tells us it was a Denisovan who lived between 164,000 to 131,000 years ago. Moreover, scientists looked closely at the tooth interior. Through the protein analysis and a 3D X-ray reconstruction, they found out that the structure was close to the Tibetan Denisova specimen. It’s different from modern humans and other ancient species, though.
“The proteins allowed us to identify the sex – female – and confirm its relation to the Homo species,” said Demeter, a researcher at the University of Copenhagen in Denmark. The university is saving the tooth temporarily. In addition to being similar to Denisovans, the structure was close to the teeth of Neanderthals – and they were genetically close to Denisovans. Why is it not a Neanderthal then? Well, there has been no Neanderthal so far east yet. That said, Denisova specimens are more common in the area. The sudden discovery was still a surprise to most researchers, including Laura Shackelford, the paleoanthropologist from the University of Illinois Urbana-Champaign.
“We’ve been working there for more than 10 years,” she said, “and we still haven’t made it off the first mountain.”
Sources: National Geographic, NY Times, The Guardian, Reuters