Ancient Human Fossil Unearthed in China Challenges Human Family Tree
An international team of scientists has made an intriguing discovery in China – an ancient human fossil that does not fit into any known hominin lineage. The fossil, named HLD 6, was found in Hualongdong in East Asia in 2019 and has puzzled experts ever since.
The remains, including a jaw, skull, and leg bones, exhibit a unique combination of characteristics that cannot be attributed to any existing branch of the human family tree. Researchers from the Chinese Academy of Sciences (CAS), in collaboration with scientists from Xi’an Jiaotong University, the University of York in the UK, and Spain’s National Research Center on Human Evolution, believe that this discovery points to the existence of an entirely new lineage.
The face of HLD 6 bears similarities to modern humans, diverging from the lineage that gave rise to Neanderthals. At the same time, its lack of a chin resembles that of the Denisovans, an extinct species of ancient humans in Asia. This indicates a hybridization between the branch that led to modern humans and the branch that produced other ancient hominins in the region, such as Denisovans.
In China, previous hominin fossils from the Pleistocene period have often presented a challenge in terms of classification. They do not neatly fit into a specific lineage and are often considered intermediate variations. However, this linear interpretation has not been widely accepted. The newly discovered fossil presents a more complex and ambiguous picture of human evolution in East Asia.
Genomic studies conducted on Neanderthal remains in Europe and western Asia have previously hinted at the existence of a fourth lineage of hominin during the Middle to Late Pleistocene. However, no such group has been officially identified in the fossil record. The HLD 6 fossil may serve as a missing piece of the puzzle, shedding light on this mysterious lineage.
The fossilized jaw and skull, believed to have belonged to a 12- or 13-year-old individual, exhibit a mixture of modern-human and primitive traits, further complicating the path to modern humans. This mosaic of physical features supports the idea that three distinct lineages coexisted in Asia – the lineage of Homo erectus, the Denisovans, and this newly discovered lineage, which is closely related to modern humans.
While Homo erectus only appeared in China around 120,000 years ago, it seems that some modern features existed in the region long before that. This suggests that the last common ancestor of Homo erectus and Neanderthals may have originated in southwest Asia before spreading to other continents.
The researchers emphasize the need for further archaeological research to confirm this theory and gain a deeper understanding of human evolution in East Asia. The study detailing this groundbreaking finding has been published in the Journal of Human Evolution.