Moroccan Cave Fossils Capture a Crossroads in Modern Human Evolution
Ancient bones discovered in a cave in Casablanca, Morocco, may fill in some gaps in human evolution.
The cave, known as Grotte à Hominidés, contains assemblages of jawbones, teeth and vertebrae dating to 773,000 years ago, around the time when modern humans began to diverge from the ancestors we share with Neanderthals. Denisovans.
Detailed analysis shows that the remains belong to an early African hominin population that lived near this evolutionary crossroads and show a mix of traits later seen in modern humans. neanderthalsas well as more archaic traits inherited Previous members of the genus Homo.
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It’s a finding that helps firmly pin down humanity’s origins far from Africa. confusion ensued with homo ancestor Hominin fossils in Europe similar time period.
One of the lower jaw bones photographed during the excavation. (JP Raynal, Casablanca Prehistory Program)
“Fossils from Grotte à Hominidés may be the best candidates we currently have for African populations close to the roots of these common ancestors, thus strengthening the view that our species has a deep African origin.” says anthropologist Jean-Jacques Hublin Dr. from the Max Planck Institute for Evolutionary Anthropology in Germany, who led the research.
Humanity’s evolutionary history is complex. complicatedand mostly lost to the ravages of time and decay. The evidence we have is often fragmentary and difficult to interpret; This is made even more complicated by the problem of accurate dating. Many hominin fossils therefore have a wide range of dates.
The diversity of the Grotte à Hominidés fossils makes them exciting.
The Earth’s magnetic poles change places from time to time. These events are recorded geologically as follows: ferromagnetic materials in rock realignment. The last change was: Matuyama-Brunhes’ returnIt occurred approximately 773,000 years ago and may have lasted at least several thousand years.
This is recorded very, very clearly in the sediments at Grotte à Hominidés, and fossilized bones were found in the same layer as the signature of the magnetic reversal. This dates them very clearly and precisely to 773,000 years ago; around the time period when most anthropologists think the process of human differentiation began.
So that’s part of the picture. From the sediments in which they were found, we know that these bones belong to a population that lived during a critical period in human history.
The next step for the researchers was to look closely at the bones themselves and see what they revealed about what that population was like.
The 773,000-year-old hominin bones found at Grotte à Hominidés included jawbones, teeth and vertebrae. (Hublin et al., Nature2025)
Among the hominin bones in the cave were two adult jawbones and one from a very young child. There were also a small number of teeth and vertebrae, as well as part of the femur.
Even though these ruins are few, they can tell us a lot. For example, jaw bones are long, low and narrow, and their joints recede; these features differ from modern humans and Neanderthals and are more similar to older members of the species. Homofor example erectus.
The teeth, on the other hand, were smaller and more similar to modern human teeth.
The CT scan allowed researchers to examine a structure inside the teeth known as dentition. enamel-dentin junction. The shape of this structure showed some similarities to both. erectus And H. ancestorbut it was clearly different from both.
“The teeth of Grotte à Hominidés retain many primitive features in terms of their shape and nonmetric features, and lack features characteristic of Neanderthals.” says anthropologist Shara Bailey from New York University.
“In this sense they are different homo ancestorThey are starting to resemble Neanderthals in some of their features. “Tooth morphological analyzes suggest that regional differences in human populations may have already existed at the end of the Early Pleistocene.”
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Considering the geographical distinction H. ancestor and new Moroccan fossils, researchers suspect the two groups were probably different from each other; The Grotte à Hominidés population belongs to an African stem lineage that would later give rise to modern humans and H. ancestor It represents a related sister population on the Eurasian side of the early human lineage divide.
Meanwhile, the mosaic mix of features at Grotte à Hominidés points to a period of transition. The mix of features suggests that these fossils should be placed at the African root of modern humans’ evolutionary lineage; The population is unlikely to represent the last common ancestor between modern humans and their relatives, but it is close enough to provide new insight into how this divergence arose.
“Origin sapiensand the precise timing of the divergence of ancestral populations from Neanderthals.Denisovan Clade continues to be a matter of debate” researchers write in their paper.
“Our findings are not only consistent with the phylogenetic structure derived from paleogenetic data, but also highlight that the Maghreb is a crucial region for understanding the emergence of our species, strengthening the case for an African rather than a Eurasian ancestor. sapiens“
The research was published at: Nature.
