The early history of our species is complicated: crossbreeds with the Neanderthals and other early hominids, as well as multiple spurts of spread, make it difficult to trace the evolution of Homo sapiens. A fossil discovery in Israel now makes things even more confusing. The bones, which are around 140,000 to 120,000 years old, have the characteristics of Neanderthals and archaic forms of Homo sapiens. However, they clearly differ from the anatomically modern representatives of our species that occurred at the same time in the region. According to the scientists, this “Nesher Ramla Homo” is a previously unknown population of early humans.
The Levant is a region that plays a special role in human history. It forms a bridge between Africa and Eurasia and was therefore already a passage corridor for the early representatives of the genus Homo on the way from their African places of origin to the world. At the same time, this area also offered the best conditions to settle there. Fossil finds from Israel show that both Neanderthals and representatives of the anatomically modern Homo sapiens lived there – sometimes even at the same time. The first members of our species could have reached the Levant almost 200,000 years ago. However, archaeologists have also discovered some relics in some caves in Israel, including the Quesem Cave, whose assignment is less clear – some seem too old for Homo sapiens, others are more archaic in their anatomy than they should be.
Features of Neanderthals and archaic homo
Now more finds deepen the mystery of the early inhabitants of the Levant. Israel Hershkovitz from Tel Aviv University and his team discovered them during an emergency excavation on the site of the Nesher cement plant near the Israeli city of Ramla. At a depth of eight meters, they encountered thousands of flint blades, animal bones and human remains. These are an almost complete lower jaw and a skullcap, which, according to dating, are between 140,000 and 120,000 years old. To find out what kind of people these relics came from, the researchers subjected them to in-depth morphological analyzes, created virtual reconstructions and compared the characteristics with those of other fossils from Europe, Africa, Asia and the Levant.
It turned out that the roof of the skull is strikingly flat and thick. “This points to an archaic, low skull shape that differs substantially from that of early and modern Homo sapiens, because this has a domed parietal bone with a pronounced curve,” write Hershkovitz and his colleagues. The angle of the cranial sutures, at 91.1 degrees, is more suitable for archaic representatives of the genus Homo than for Homo sapiens, where this angle is 99.4 degrees. In the computer-aided comparisons, this NR-1 baptized find landed between Neanderthals and archaic forms of Homo sapiens. The jawbone, baptized NR-2, also shows a mixture of features from these two groups, the researchers report. The bone resembles in some parts a fossil classified as Homo heidelbergensis from the Spanish Atapuerca, while a molar in the jaw comes close to that of the Neanderthal.
A still unknown population
According to Hershkovitz and his team, everything indicates that these fossils were not an anatomically modern Homo sapiens, but a previously unknown variant of early humans. “This is an extraordinary discovery,” says Yossi Zaidner from the Hebrew University of Jerusalem, who, with a second team, has primarily examined the stone tools of this group of people. “We would never have thought that representatives of an archaic homo were living in this region alongside Homo sapiens so late in human history.” The scientists deliberately did not give this population a species name because it was still unclear, but instead called it the ” Nesher Ramla Homo ”. So far it has not been possible to extract DNA from the fossil finds, so that the genetic classification remains open.
However, the scientists believe it is quite likely that the Nesher Ramla homo was just one representative of a large population of early humans that may have existed in the Levant for 400,000 years. Other fossils with mixed characteristics, including the 400,000 year old teeth from the Quesem Cave and 250,000 year old relics from the Zuttiyeh Cave in Israel, could also come from this type of person. “The discovery of this new type of homo is of great scientific importance. It enables us to classify previously found human fossils, adds another piece to the puzzle of human evolution and could help to understand the early migrations of humans, ”says Hershkovitz. Marta Mirazon Lahr from the University of Cambridge sees it similarly in an accompanying comment: “The new finds from Nesher Ramla further add to the complexity of the evolutionary landscape of the hominins,” she writes. Even if the interpretation of the fossils and stone tools is sure to cause controversy among paleoanthropologists, this is a significant discovery.
(Video: Tel-Aviv University)
Source: Israel Hershkovitz (Tel Aviv University) et al., Science, doi: 10.1126 / science.abh3169; Yossi Zaidner (The Hebrew University of Jerusalem) et al., Science, doi: 10.1126 / science.abh3020