An ancient jawbone discovered off the coast of Taiwan was identified as belonging to a Denisovan. The research was published in the latest issue of the scientific journal Science. "It opens an important door in the study of human evolution," said Antonio Rosas, head of the Paleoanthropology Group at the National Museum of Natural Sciences (MNCN-CSIC), according to The Independent.
The jawbone, named Penghu 1, was retrieved from the seafloor in the Penghu Channel, an area that was once dry land during the Pleistocene epoch. It was pulled from the seabed by a fisherman more than 20 years ago, about 25 kilometers off Taiwan's west coast. For years, scientists failed to determine exactly where Penghu 1 fit in the human family tree, according to CNN.
Although DNA could not be extracted directly from the Penghu 1 fossil due to material degradation, scientists applied mass spectrometry techniques to analyze the jawbone and determine that it belonged to a male Denisovan, according to The New York Times. "Proteins are made up of amino acids, which are linked together in a certain order. The order in which those amino acids are placed is determined by the DNA sequence in our genes," explained Frido Welker, a molecular anthropologist and study co-author at the University of Copenhagen.
This discovery provides new evidence about the Denisovans, a mysterious group of early human ancestors who likely lived from around 370,000 years ago to at least 30,000 years ago and interacted with Neanderthals and Homo sapiens. This marks the third confirmed location where Denisovan fossils have been found, illustrating their wide geographical spread across Eurasia.
Previously, most Denisovan fossils were obtained from the Denisova Cave in Siberia, including a 40,000-year-old finger bone and a few teeth. Another find was a mandible from Baishiya Cave on the Tibetan Plateau. The recent identification of Penghu 1 as Denisovan reveals that these ancient humans inhabited diverse environments, ranging from the chilly Siberian mountains to the high elevations of the Tibetan Plateau to the warmth of Laos and the subtropical shoreline of Taiwan.
The condition of the fossil made it impossible to study ancient DNA directly, which made it exceptionally difficult for researchers to determine its age. Researchers estimate that the fossil is either 10,000 to 70,000 years old or 130,000 to 190,000 years old, based on associated animal fossils and dating challenges. Its composition of marine invertebrates indicates it dates to the Pleistocene era.
The Penghu 1 jawbone displays Denisovan-like morphology, revealing a robust mandibular structure with large molars and distinctive root structures. "Denisovans had thicker jaws and larger teeth, with the mandible and teeth of the Denisovan individual being very robust and larger compared to both modern Homo sapiens and Neanderthals," according to The Independent.
Genetic evidence shows that Denisovans are a sister group to Neanderthals, and studies confirmed their close relationship. Denisovans lived alongside Neanderthals and modern humans, and genetic analysis revealed that Denisovans, like Neanderthals, had once interbred with early modern humans.
The researchers identified 4,241 amino acid residues from the samples, including two variants unique to Denisovans, allowing the fossil to be directly associated with this extinct human species.
The article was written with the assistance of a news analysis system
