The dragon man and the Nesher Ramla people: the latest pieces to the puzzle of human evolution
Recent analyses of fossils from Israel and China are making scientists reevaluate their conclusions about the evolution of humans. As the only remaining human species for at least 40,000 years, it may be odd to learn that we, Homo sapiens, are just one of many species of humans that have dwelled on Earth in the past hundreds of thousands of years.
The evolutionary history of our lineage goes back to approximately 6 million years ago, when our earliest-known ancestor, the Sahelanthropus, emerged, separating us from other primates. Our species, however, only appeared more than five million years later, around 300,000 years ago. In the meantime, many other human species lived, evolved, and went extinct.
The evolutionary tree of the human lineage features many human species that have become extinct. “Ma” stands for “million years ago” https://www.biorxiv.org/content/10.1101/434894v1.full
To figure out the number, identity, and chronology of those species, scientists rely on fossils that first need to be discovered and then accurately identified, both of which are extremely difficult tasks. Even though fossils may provide DNA evidence on rare occasions, the shape and form of the physical evidence is the only data available for scientists most of the time. Understanding human evolution is like trying to make sense of a puzzle missing most of its pieces. Each newly found piece carries the potential to make us rethink the position of all other pieces and reassess all previous assumptions about the whole final picture.
Conclusions questioned as discoveries add to the puzzle
During the last two decades, scientists have discovered many new species of humans that were contemporary to our species (Homo sapiens) in the Middle (780,000-130,000 years ago) and Late Pleistocene (130,000-11,700 years ago). The debates over what these new findings mean and how they add to the puzzle of the evolutionary history of our lineage are ongoing. Some scientists have gone as far as saying that we might just set aside previous conclusions and reinterpret all our evidence from scratch.
From skull fragments from 120,000-140,000 years ago, found at Nesher Ramla in central Israel, Dr. Israel Hershkovitz, an anthropologist at Tel Aviv University, and colleagues say they may have identified a new group of humans. Until now, only H. sapiens was thought to occupy the Levant region at that time. However, the fossils found were not from H. sapiens. The jaw and teeth were similar to those of Neanderthals – the closest known relatives of modern humans – but the skull shape was more archaic, and there are no records of that species in the region before 70,000 years ago. This unexpected combination of characteristics matches many other fossils from Israel that similarly do not fit into any previously known group. In their articles, the group led by Dr. Hershkovitz argues that these fossils belong to a previously unknown hominin population, the Nesher Ramla people. Artifacts found with the fossils suggest that the Nesher Ramla people used the same stone tools as the H. sapiens living in the area at that time, which indicates that they may have lived together and possibly interbred.
The Levant region.
Dr. Philip Rightmire, a paleoanthropologist at Harvard University, argues that the skull could be an early Neanderthal. Thus, the fossil would actually reveal an earlier occupation of Neanderthals in the region than previously thought, rather than a new hominin population, as Dr. Hershkovitz’s research suggests. Recognizing the similarity of the dragon man’s jaw to the jaw of Neanderthals, Dr. Hershkovitz says that the Nesher Ramla people could also have been the ancestors of Neanderthals in Europe.
In China, another mysterious piece of this puzzle was recently analyzed and has added fuel to the debate. A mysterious hominin skull from the middle Pleistocene, approximately 140,000 years old, was donated to the Hebei GEO University in Shijiazhuang in 2018. The fossil was discovered in 1933 by a worker during a bridge construction in the Heilongjiang province. The scientists named the fossil “dragon man” inspired by the name of the Heilongjiang province, which means Black Dragon River.
The dragon man’s skull https://www.bbc.com/news/science-environment-57432104
In a recent paper, Dr. Qiang Ji, paleontologist at Hebei GEO University, and colleagues assessed the skull and proposed it belongs to a previously unknown human species, the Homo longi. Compared to H. sapiens, the skull of the dragon man is large and thick, with big, squarish eye sockets, low cheekbones, large teeth, and a wide pallet. Dr. Qiang argues that H. longi might be our closest relatives in the human evolutionary tree.
The Heilongjiang province, China
However, it is difficult to establish the validity of a new species based on a single skull, especially when it was removed from its original location. Dr. Jeffrey Schwartz, an anthropologist and evolutionary biologist at the University of Pittsburgh, argues that even though it is possible that there were more human species in Asia during the Pleistocene than we currently recognize, more evidence is still necessary to determine that this skull belongs to a new species indeed.
Several distinct middle Pleistocene Homo fossils like the dragon man’s skull have already been found in China, including regions like Dali, Jinniushan, Hualongdong, and the Tibetan Plateau.
Dr. Marta Lahr, from the University of Cambridge, hypothesizes that the dragon man may actually be a Denisovan. The Denisovans were a group of humans, closely related to Neanderthals and modern humans. They were first identified from the DNA of the fossil of a finger bone from 50,000-30,000 years ago, found in Russia. The group has been described as a “genome in search of a fossil record”. Dr. Lahr says that DNA evidence suggests that a jawbone found in the Tibetan Plateau might be a Denisovan. The similarity between that jawbone from Tibet and the jawbone of the dragon man suggests that we possibly found the first skull of a Denisovan.
Whether these discoveries are evidence of early Neanderthals coming from Europe, the Nesher Ramla people, the Denisovan, or even an entirely separate previously unknown species is still a matter of great debate in the scientific community. Dr. Jeffrey Schwartz, goes as far as questioning if some fossils currently identified as H. sapiens might actually be something else, and advocates that it might be necessary to “start from scratch” and “look at everything from the beginning.”