ALTAI KRAI — Two teeth discovered in Denisova cave, Siberia, may offer a clue about the modern human’s ancient relative, the Denisovans. A study on the issue was published on the Journal of the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

The species was identified back in 2010 when researchers found the finger bone of a young female, which was tested through a DNA analysis that confirmed Denisovans were different from Homo sapiens and Neanderthals, and that her kind interbred with other hominids and modern humans.

The Denisova cave in the Altai mountains, where a toe bone fragment was found that let scientists read the Neanderthal genome. Photo: Bence Viola/PA

The tooth found recently was the second one to be discovered in the cave, and it allowed scientists to confirm that Denisovans had characteristically large molars. Bence Viola, a researcher from the University of Toronto, told CBC that it was comparable in size to the hominids that lived around two or three million years ago, however, its age shows that it’s quite recent.

The genome of a particular species undergoes various genetic mutations as time goes by. When the new tooth’s DNA was compared to the former tooth and finger bone, scientists discovered that it had way more mutations than the other fossils, suggesting a gap of 60,000 years that also gave a hint about the species’ longevity.

Denisova molar, distal. Image courtesy of Max Planck Institute for Evolutionary Anthropology

Since the species survived for a long time, this lead researchers to believe that Denisovans managed to grow a large population, which spread around different geographical locations for a long period before they vanished. Viola assured to be convinced, in front of the evidence gathered from genetic data, that the species had spread over large parts of Asia.

The DNA analysis also proved that Denisovans had a more diverse genetic pool that researchers initially considered. “The world at that time must have been far more complex than previously thought. Who knows what other hominids lived and what effects they had on us?,” said Susanna Sawyer, geneticist from the Max Planck Institute for Evolutionary Anthropology, in an interview with National Geographic.

A tooth from Denisova Cave in the Altai Mountains of Siberia, which DNA shows belonged to a previously unknown archaic human population, now called the Denisovans. Photo: Max Planck Institute

Scientists would need to recollect more evidence in order to predict Denisovans’ behavior or looks, however, as they’re believed to have spread across Asia, researchers think it’s likely that they’ll eventually find a full skeleton.

María Martinón-Torres, anthropologist from the University of College London who wasn’t involved in the study said that paradoxically, while researchers still didn’t know much about Denisovans’ appearance, they knew a lot about them from a genetic point of view.

Source: UPI