Fossil Finds Unlock Secrets of Human Evolution History

Fossils discovered in a Moroccan cave dating back 773,000 years are providing new evidence in the debate surrounding the origins of modern humans, Neanderthals, and Denisovans. The discovery points to a long evolutionary history in North Africa, predating the emergence of Homo sapiens, and reinforces Africa’s central role in human evolution.

New Fossil Discovery Sheds Light on Human Origins

Excavations have been ongoing since 1994 at the Hominid Cave at Thomas Quarry I, southwest of Casablanca, Morocco. The research program, Prehistory of Casablanca, is a collaboration between Morocco’s National Institute of Archaeological Sciences and Heritage and the French Ministry for Europe and Foreign Affairs.

The team unearthed hominin fossils alongside thousands of animal remains and approximately 300 artifacts made of quartzite and flint. Evidence suggests the site served as a den for large carnivores, including a hominin femur bearing bite marks from a hyena.

The hominin remains include a nearly complete adult jaw, half of another adult jaw, a young child’s jawbone, cervical and thoracic vertebrae, and several teeth.

These fossils are the oldest hominin fossils discovered in Morocco with a confirmed date, offering new insights into a poorly understood period of human evolution. They document populations existing between early Homo species and more recent lineages.

Dating the Fossils with Palaeomagnetism

The fossils were dated to approximately 773,000 years ago using palaeomagnetism, the study of Earth’s ancient magnetic field. Analysis of the sediments in the Hominid Cave revealed changes in the magnetic field, specifically identifying the last geomagnetic reversal, a period when the Earth’s magnetic field flipped.

This reversal serves as a reliable chronological marker, and the fossil remains date precisely to this period, providing one of the most accurate datings of hominin fossils from the Pleistocene era.

Implications for Modern Human Evolution

The Casablanca fossils date to a time when Homo erectus was spreading out of Africa, and older hominin groups like Australopithecus and Paranthropus were dying out. The fossils exhibit a combination of archaic traits characteristic of Homo erectus and more advanced traits related to Homo sapiens.

These findings suggest the population inhabited a period close to the split between the African lineage leading to Homo sapiens and the Eurasian lineages that produced Neanderthals and Denisovans. The fossils offer a new perspective, potentially linking to the oldest known Homo sapiens fossils found at Jebel Irhoud in Morocco, dated to around 315,000 years ago.

The discoveries reinforce the idea that the deep roots of Homo sapiens are in Africa.

North Africa’s Importance in Human Evolution

North-west Africa, along with East and Southern Africa, is a key region for understanding the evolution of Pleistocene hominins. The Mediterranean Sea likely acted as a biogeographical barrier, contributing to the divergence between African and Eurasian populations. The Sahara desert’s changing size also likely influenced population structure.

The Moroccan fossils confirm the ancient and deep roots of the human species and highlight the crucial role of North-west Africa in the major stages of human evolution.