Periodic Reporting for period 1 - MINERVA (Mid-Pleistocene environments of the lower Vaal River)
Período documentado: 2019-05-01 hasta 2021-04-30
The evolution of our human species has been intimately tied to environmental dynamics and landscape change that impacted the distribution and accessibility of food resources. The adaptability of hominins to shifts in biomes and, in turn, changing resource availability is key to the evolutionary success of our species. While previous research has largely focused on pointing out coincidences of major evolutionary events with global climate shifts, the interdisciplinary project ‘MinErVa: Mid-Pleistocene Environments of the lower Vaal River’ used innovative archaeological science methods to pinpoint precisely if, when, and how biome changes and attendant shifts in resource distribution at regional scales influenced the evolution of Homo sapiens 300 000 to 100 000 years ago in South Africa. The project objective was to establish the nature of long-term climate change at regional scales by investigating vegetation changes; shifts in aridity levels and rainfall seasonality. In doing so, the MinErVa project reconstructed the distribution of plant and animal resources accessed by early hominids and explored human adaptation to changes in these resources. The MinErVa project showed that early humans at Pniel 6 were inhabiting an area dominated by tropical grasses and a mixture of modern and wetland adapted animal species in the interior of South Africa. They used a large variety of stone materials to prepare flakes and blades to exploit this environment. Arid and humid phases can be detected from palaeoenvironmental records in the archaeological sites of the region, showing the impact of the rapid climatic changes of the Mid- to Late Pleistocene.
The adaptation of early Homo sapiens to changing environment and prey choices in the arid interior of southern Africa was explored through synthesis of isotopic, zooarchaeological, geoarchaeological and lithic data sets recovered from excavations at Pniel 6, and comparison to archaeological sites of similar age in the region.
To test the hypothesis that the Mid-Pleistocene environment at Pniel included phases of persistent wetness and significant biome shifts, stable isotope analysis on tooth enamel of Zebras and Hartebeest from Pniel 6 was used for palaeoenvironmental reconstruction. Both species show a dominance of tropical grasses in their diet. The results are comparable to the results from sites of similar age in the region. Furthermore, the values for Pniel 6 suggest a potential interglacial age for the samples when aridity levels were similar to the early Holocene.
The third part of the project was to test the application of sediment biomarker isotope analysis at Pniel 6 and nearby sites with known environmental records (Wonderwerk Cave, Kathu Pan). N-alkanes could be extracted from all samples and show that it is possible to adapt this method, which originated in marine geosciences, to terrestrial sediments from archaeological sites of Holocene and Pleistocene age. Preservation is given despite the arid setting and the different site types (open air, cave, sinkholes).
Results of the project are published in two publications in international peer-reviewed journals and have been presented academic conferences and invited talks. Two more publications are currently in preparation.
To test the hypothesis that the Mid-Pleistocene environment at Pniel included phases of persistent wetness and significant biome shifts, stable isotope analysis on tooth enamel of Zebras and Hartebeest from Pniel 6 was used for palaeoenvironmental reconstruction. Both species show a dominance of tropical grasses in their diet. The results are comparable to the results from sites of similar age in the region. Furthermore, the values for Pniel 6 suggest a potential interglacial age for the samples when aridity levels were similar to the early Holocene.
The third part of the project was to test the application of sediment biomarker isotope analysis at Pniel 6 and nearby sites with known environmental records (Wonderwerk Cave, Kathu Pan). N-alkanes could be extracted from all samples and show that it is possible to adapt this method, which originated in marine geosciences, to terrestrial sediments from archaeological sites of Holocene and Pleistocene age. Preservation is given despite the arid setting and the different site types (open air, cave, sinkholes).
Results of the project are published in two publications in international peer-reviewed journals and have been presented academic conferences and invited talks. Two more publications are currently in preparation.
The MinErVa project is truly interdisciplinary. It combined traditional archaeological fieldwork with Quaternary science to answer archaeological as well as paleoenvironmental questions. It is advancing research in several ways. In the field of Paleolithic archaeology, it adds new records of environmental change to test the hypothesis of early humans evolving during phases of climatic change. The records are obtained from a modern excavated archaeological site in a region with few sites of this age. MinErVa explored the use of a new and upcoming method to reconstruct terrestrial palaeoenvironments, leaf-wax n-alkane isotope analysis. This is one of the first studies of this kind at an archaeological site in southern Africa and provides the research field with a valuable tool to create proxy records in arid environments. These records can be used to explore the drivers of climate forcing, and in turn improve models for future climate prediction locally and worldwide.