Photo credit: phys.org
Recent research led by Alfonso Benito Calvo, a geologist from the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has unveiled significant findings at the Guefaït-4 archaeological site in Morocco. This multidisciplinary study, published in Nature Communications, provides a detailed reconstruction of the ecological landscape in northern Africa approximately 2.5 million years ago.
The study reveals a complex environment characterized by varying degrees of aridity, alongside patches of forest, wetlands, and open terrains. Such insights into the paleoecology are vital for understanding how Plio-Pleistocene hominins adapted to the fluctuating ecosystems that defined that era.
According to Iván Ramírez-Pedraza, the principal investigator from IPHES-CERCA, this research establishes the first comprehensive ecological framework for northern Africa, an area previously lacking precise data unlike better-studied regions in eastern and southern Africa.
Utilizing a combination of sophisticated analytical approaches, the researchers gathered crucial ecological data. The core methodologies included analyzing stable isotopes and examining dental wear patterns found on the fossilized remains of large vertebrates from Guefaït-4.
The isotopic analysis of dental enamel offered insights into the dietary habits and the thermal conditions of the water sources in the area. Additionally, the dental microwear analysis identified various wear patterns on teeth that reflect the food consumed by these animals.
Complementing these studies, the team conducted pollen analyses and examined plant wax isotopes in sediment layers, which helped them identify a diverse array of micromammals, microcrustaceans, and algae that thrived in this ancient environment.
Hominin Expansion and Environmental Context
Stratigraphic examinations by CENIEH reveal that the Guefaït-4 site developed during a wetter climatic phase that promoted the establishment of lagoons at the base of surrounding mountains, facilitating the preservation of fossil remains within mud and carbonate deposits.
The transition from the Pliocene to the Pleistocene, marked by global cooling and increasing aridity, also influenced local ecosystems, leading to both arid conditions and a mosaic of habitats. This dynamic environment, coupled with periods when the Sahara experienced increased vegetation, may have played a crucial role in the migration of mammalian populations, including early hominins, from central and eastern Africa into northern regions.
Fossil evidence suggests that the earliest hominins reached northern Africa around the time of the Plio-Pleistocene transition, approximately 2.5 million years ago, specifically at the Ain Boucherit site in Algeria. Understanding the ecological conditions these early humans encountered is essential for comprehending their migration patterns and survival strategies in unfamiliar territories.
Dr. M. Gema Chacón, a researcher at IPHES-CERCA and project co-director, highlighted the significance of the proximity between Guefaït and Ain Boucherit, stating that knowledge of the broader ecological context offers critical insights into the resources available to the first hominins as they adapted to new environments.
For further reading: Iván Ramírez-Pedraza et al, Arid, mosaic environments during the Plio-Pleistocene transition and early hominin dispersals in northern Africa, Nature Communications (2024). DOI: 10.1038/s41467-024-52672-0
Source
phys.org