Middle Stone Age
The Middle Stone Age was a period of African prehistory between the Early Stone Age and the Later Stone Age. It is generally considered to have begun around 280,000 years ago and ended around 50–25,000 years ago. The beginnings of particular MSA stone tools have their origins as far back as 550–500,000 years ago and as such some researchers consider this to be the beginnings of the MSA.
The MSA is often mistakenly understood to be synonymous with the Middle Paleolithic of Europe, especially due to their roughly contemporaneous time span; however, the Middle Paleolithic of Europe represents an entirely different hominin population, Homo neanderthalensis, than the MSA of Africa, which did not have Neanderthal populations. Additionally, current archaeological research in Africa has yielded much evidence to suggest that modern human behavior and cognition was beginning to develop much earlier in Africa during the MSA than it was in Europe during the Middle Paleolithic.
Evidence for symbolic behavior during the Middle Stone Age includes the deliberate use and long-distance transport of ochre in southern Africa and the production of perforated shell beads in North Africa. These materials suggest that early Homo sapiens were expressing social identity and maintaining exchange networks as early as 100,000–70,000 years ago, well before later Upper Paleolithic developments.
The MSA is associated with both anatomically modern humans as well as archaic Homo sapiens, sometimes referred to as Homo helmei. Early physical evidence comes from the Gademotta Formation in Ethiopia, the Kapthurin Formation in Kenya and Kathu Pan in South Africa.
Regional development
There are MSA archaeological sites from across the African continent, conventionally divided into five regions: northern Africa, comprising parts of the modern countries of Morocco, Algeria, Tunisia, and Libya;eastern Africa, stretching roughly from the highlands of Ethiopia to the southern part of Kenya;
central Africa, stretching from the borders of Tanzania and Kenya to include Angola; southern Africa, which includes the numerous cave sites of South Africa; and western Africa.
In northern and western Africa, the wet-dry cycles of the modern Sahara desert has led to fruitful archaeological sites followed by completely barren soil and vice versa. Preservation in these two regions can vary, yet the sites that have been uncovered document the adaptive nature of early humans to climatically unstable environments.
Eastern Africa represents some of the most reliable dates, due to the use of radiocarbon dating on volcanic ash deposits, as well as some of the earliest MSA sites. Faunal preservation, however, is not spectacular, and standardization in site excavation and lithic classification was, until recently, lacking. Unlike northern Africa, shifts between lithic technologies were not nearly as pronounced, likely due to more favorable climatic conditions that would have allowed for more continuous occupation of sites. Central Africa reflects similar patterning to eastern Africa, yet more archaeological research of the region is certainly required.
Southern Africa consists of many cave sites, most of which show very punctuated starts and stops in stone tool technology. Research in southern Africa has been continuous and quite standardized, allowing for reliable comparisons between sites in the region. Much of the archaeological evidence for the origins of modern human behavior is traced back to sites in this region, including Blombos Cave, Howiesons Poort, Still Bay, and Pinnacle Point.
Transition from Acheulean
The term "Middle Stone Age" was proposed to the African Archaeological Congress by Goodwin and Van Riet Lowe in 1929. Theuse of these terms was officially abandoned in 1965, although the term remains in use in the context of sub-Saharan Africa, beginning with a transitional late Acheulean period known as the Fauresmith industry. The Fauresmith industry is poorly dated, according to Herries beginning around 511-435 kya. This time, rather than the actual end of the Achaeulean around 130 kya is taken as the beginning of the MSA.
The MSA so defined is associated with the gradual replacement of archaic humans by anatomically modern humans.
In a different convention, MSA refers to sites characterized by the use of Levallois methods for flake production, to the exclusion of Acheulean sites with large cleavers or handaxes.
Following McBrearty and Tryon, the term "early MSA" refers to sites predating the 126 kya interglacial, and
"later MSA" refers to site younger than 126 kya.
In this convention, Fauresmith sites of 500 to 300 kya are within the ESA, and the MSA begins after about 280 kya and is largely associated with H. sapiens, the earliest reliably dated MSA site in East Africa being Gademotta in Ethiopia,
at 276 kya.
The Middle Awash valley of Ethiopia and the Central Rift Valley of Kenya constituted a major center for behavioural innovation. It is likely that the large terrestrial mammal biomass of these regions supported substantial human populations with subsistence and manufacturing patterns similar to those of ethnographically known foragers.
Archaeological evidence from eastern Africa extending from the Rift Valley from Ethiopia to northern Tanzania represents the largest archaeological evidence of the shift from the Late Acheulian to the Middle Stone Age tool technologies. This transition is characterized by stratigraphic layering of Acheulian stone tools, a bifacial handaxe technology, underneath and even contemporaneous with MSA technologies, such as Levallois tools, flakes, flaked tools, pointed flakes, smaller bifaces that are projectile in form, and, on rare occasions, hafted tools. Evidence of the gradual displacement of Acheulian by MSA technologies is further supported by this layering and contemporaneous placement, as well as by the earliest appearance of MSA technologies at Gademotta and the latest Acheulian technologies at the Bouri Formation of Ethiopia, dated to 154 to 160 kya. This suggests a possible overlap of 100–150 thousand years.
Late Acheulean artefacts associated with Homo sapiens have been found in South African cave sites. The Cave of Hearths and Montague Cave in South Africa contain evidence of Acheulian technologies, as well as later MSA technologies, however there is no evidence of crossover in this region.
ESA Acheulean sites are well documented across West Africa but mostly remain undated.
A few late Acheulean sites have been dated. Middle Pleistocene sites are known from the northern Sahelian zones, while Late Pleistocene sites are known both from northern and southern West Africa. Unlike elsewhere in Africa, MSA sites appear to persist until very late, down to the Holocene boundary, pointing to the possibility of late survival of archaic humans, and late hybridization with H. sapiens in West Africa. Furthermore, such results highlight significant spatiotemporal cultural variability and suggest that long inter-group cultural differences played a major role in later stages of human evolution in Africa.
Lithic technology
Early blades have been documented as far back as 550–500,000 years in the Kapthurin Formation in Kenya and Kathu Pan in South Africa. Backed pieces from the Twin Rivers and Kalambo Falls sites in Zambia, dated at sometime between 300 and 140,000 years, likewise indicate a suite of new behaviors. A high level of technical competence is also indicated for the c. 280 ka blades recovered from the Kapthurin Formation, Kenya.The stone tool technology in use during the Middle Stone Age shows a mosaic of techniques. Beginning approximately 300 kya, the large cutting tools of the Achuelian are gradually displaced by Levallois prepared core technologies, also widely used by Neanderthals during the European Middle Palaeolithic. As the MSA progresses, highly varied technocomplexes become common throughout Africa and include pointed artifacts, blades, retouched flakes, end and side scrapers, grinding stones, and even bone tools. However, the use of blades is seen at many sites as well. In Africa, blades may have been used during the transition from the Early Stone Age to the Middle Stone Age onwards. Finally, during the later part of the Middle Stone Age, microlithic technologies aimed at producing replaceable components of composite hafted tools are seen from at least 70 ka at sites such as Pinnacle Point and Diepkloof Rock Shelter in South Africa.
Artifact technology during the Middle Stone Age shows a pattern of innovation followed by disappearance. This occurs with technology such as the manufacture of shell beads, arrows and hide working tools including needles, and gluing technology. These pieces of evidence provide a counterpoint to the classic "Out of Africa" scenario in which increasing complexity accumulated during the Middle Stone Age. Instead, it has been argued that such technological innovations "appear, disappear and re-appear in a way that best fits a scenario in which historical contingencies and environmental rather than cognitive changes are seen as main drivers".