The Buia sedimentary basin, in the Eritrean Danakil Depression, yielded over the past years a number of rich fossil outcrops dated to the final phases of the Early Pleistocene. The excavation campaigns carried out in this geo-chronologically extraordinary context gave us the opportunity to explore one of the most controversial issues in paleoanthropology, that is the transition from the first archaic forms of Homo to those from which anatomically modern Homo descends directly.
The project started in 1995 and it has been coordinated since 2010 by Sapienza University. The strength of the project is the interdisciplinary approach that involves researchers from several Italian, Eritrean and international institutions. The past campaigns brought to the discovery of many human fossil remains dated to ca. 1 Ma from the sites of Uadi Aalad and Mulhuli Amo. In Mulhuli Amo the remains attributable to at least five individuals have been found over the past years. Moreover, in November 2015 at Aalad-Amo have been discovered what appears to be the earliest H. erectus/ergaster footprints. These findings open new frontiers to the already vibrant context of the evolutionary trends in H. erectus/ergaster, and demonstrate the usefulness of similar multidisciplinary investigations in this specific portion of the African Rift.
Surveys of the palaeo-landscape, conducted over the past years brought to the identification of over 200 sites rich in both fossils and material culture, attesting the high-potential of new investigations in the area. Therefore, the constant discoveries and even the unexpected findings - like the footprints - highlight the necessity to further investigate this extraordinary portion of the Danakil depression, and to extend our knowledge on this still poorly understood phase of human evolution.
The richness of the fossiliferous areas surrounding Buia has been proven over the past decades. Apart from the uncovering of the 1 Ma H. erectus cranium that has given great insight into a crucial moment of human evolution such as the one believed to have given rise, in East Africa, to anatomically modern H. sapiens, it has in the past years constantly brought to the discovery of human fossil remains.
Similar advancement of knowledge can be achieved only through a multidisciplinary approach integrating the bio-evolutionary information with that derived from studies of cultural aspects and of the development of cognitive functions.
Moreover, it is crucial to set the evolutionary phenomena within a wider framework that takes into account both the geological and the palaeoenvironmental contexts within which the changes occurred. The current understanding of the East African paleoenvironment emphasizes the presence of extreme dynamism, in both the Red Sea and the East African rift systems, that contributed to the development of different ecosystems. It is, furthermore believed, that the variability of the ecosystems was an important factor for shaping the human evolutionary scenario and that, consequently, these two aspects are inexorably linked. The application, in this project, of new models of paleo-geographical dynamics and their associated ecosystems should substantially contribute to the general understanding of these, to date, still insufficiently understood phenomena. Furthermore, the present project foresees the elaboration of specific analytical software to investigate the possible migration models, of both Homo and the associated mammal fauna, to Eurasia during the final stages of the Lower Pleistocene and the Middle Pleistocene. Original and comparative data (e.g. www.paleodb.org; www.helsinki.fi/science/now/) will be used to construct, using an innovative methodological approach, mathematical models to understand the ecological context of the dispersal of H.erectus/ergaster to Eurasia from his place of origin in East Africa. In order to understand these mechanisms, neighboring contexts such as Sudan, Ethiopia, Kenya and even the Arabian Peninsula should also be taken into consideration.
Modern humans have unusual anatomy, subsistence strategies, landscape use, life history, and behaviour. Even though there is general consensus regarding the fact that a combination of ecological factors must have played an important role in the evolution of these characteristics that are, in most cases, defining features of our species, there is very little direct evidence in deep time of hominin gait, landscape use, group behaviour, and its ecological setting. The extremely recent discovery (2015 field campaign) of a 800 Ka hominin footprint assemblage at Aalad-Amo, and, should this be confirmed, the first set of footprints pertaining to H. erectus discovered, positions Buia among the very rare and unique sites capable of giving direct information regarding posture and locomotion. The enlargement of the exposed surface and its in-depth analysis through cutting edge techniques could provide unprecedented information regarding foot anatomy, stature, body mass and locomotor biomechanics of H. erectus/ergaster around 0.8 Ma. In addition, this finding gives scientists critical clues to understanding how hominins behaved and fared in their environment at that time, adding a new piece to the puzzle of human evolution.
Furthermore, the 2018 campaign will be focused toward the Middle Pleistocene evidence of the region, looking for an occupational continuity through the Upper Pleistocene in a central area for the emergence of Homo sapiens.
The employment of cutting edge techniques will furthermore enable the implementation and detail of the data acquired. Methodologies applied to fossils will include high resolution 3D laser scan images to integrate the microtomographic record and that will therefore render available virtual models for morphometric geometry that could be compared with open access resources (e.g. www.nespos.org) or casts. Moreover, new available technologies [25] will allow conducting an in-depth analysis of the microwear of the teeth from Uadi Aalad and Mulhuli Amo, improving the results already obtained [16] to better analyse the microscopic wear patterns to infer on the dietary habits. These to be compared with the Holocene dental human collections available from the Eritrean Danakil.
Population dynamics in Holocene East Africa focusing on bio-cultural adaptation and peopling during late prehistory and proto-history; aspects that are, to date, uninvestigated from a physical anthropological perspective. We also perform on the extant population genome-wide analyses using next generation sequencing. Through these analyses we will investigate the evolutionary history of these populations. The high amount of data will be processed using dedicated bioinformatic tools.
[16] Zanolli al 2014
[25] Strani et al 2018