Who was the last common ancestor of Homo sapiens, Neanderthals and Denisovans? 773,000-year-old fossils of early humans from Morocco now bring us a little closer to the origins of our species. The fossil jaws, teeth and vertebrae show a combination of archaic and modern features. It was probably a further developed form of Homo erectus. Comparisons with finds from Spain suggest that there may have been an exchange between African and Eurasian populations towards the end of the Early Pleistocene, but also regional differences. The results support the theory that the ancestors of our own species evolved in Africa.
The last common ancestor of Homo sapiens and its Eurasian sister species, the Neanderthals and the Denisovans, still puzzles science today. Genetic comparisons indicate that the three human species must have separated from each other around 765,000 to 550,000 years ago. But what their common ancestor looked like and where he lived is still uncertain.
Some hypotheses assumed that Homo heidelbergensis was the sought-after link, but recent studies suggest that only Neanderthals and Denisovans emerged from this early human species, while the evolutionary line of Homo sapiens split off earlier. Another candidate for a common ancestor is Homo antecessor, fossils of which were found in Spain around 774,000 years old.
Archaic and modern features
A team led by Jean-Jacques Hublin from the Max Planck Institute for Evolutionary Anthropology in Leipzig has now examined early human fossils that were found in the Grotte à Hominidés in Morocco and come from a similar time to the remains of Homo antecessor from Spain. The team dated the finds – several lower jaws, teeth and vertebrae – to be 773,000 years old. They were helped by the fact that it was precisely at this time that the Earth’s magnetic field reversed, which is reflected in the stratographic layers surrounding the fossils.
CT scans and anatomical comparisons showed that the fossils show a combination of ancient and modern features: the shape of the lower jaws corresponds more closely to that of Homo erectus and other early African hominins. The molars, on the other hand, resemble those of the first Homo sapiens and Neanderthals. Similar patterns were also found in the Spanish specimens of Homo antecessor. “These similarities reopen the question of possible exchange processes across the Strait of Gibraltar during the Early Pleistocene,” said the research team. Accordingly, the African and Eurasian populations of early human forms would not have been isolated from each other at the end of the Early Pleistocene, but would have mixed with each other.
Relatives of the last common ancestor
At the same time, Hublin and his colleagues also noticed differences compared to Homo antecessor, including in the shape of the teeth and lower jaw. Many features of the teeth from the Grotte à Hominidés are still comparatively primitive, without structures characteristic of Neanderthals. “In this sense, they differ from Homo antecessor, which already has some characteristics similar to the Neanderthals,” explains co-author Shara Bailey from New York University.
These results suggest that, despite possible exchanges, there were regional differences between early humans in North Africa and Southern Europe. “Our analysis suggests that the hominids from Morocco probably belong to an evolved form of Homo erectus more broadly in North Africa, similar to Homo antecessor in Europe,” the researchers conclude.
From Hublin and his team’s point of view, the newly discovered fossils are probably not the last common ancestor of Homo sapiens and Neanderthals, but rather a close relative. Nevertheless, the find clearly supports the thesis that our own species developed in Africa and, unlike the Neanderthals and Denisovans, does not go back to ancestors who came to Eurasia early on. “The fossils from the Grotte à Hominidés are probably the best evidence currently available for African populations close to the root of common ancestry, supporting the view of a deep African origin of our species,” says Hublin.
Source: Jean-Jacques Hublin (Max Planck Institute for Evolutionary Anthropology, Leipzig) et al., Nature, doi: 10.1038/s41586-025-09914-y