Middle Stone Age
The Middle Stone Age (or MSA) 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. The MSA is associated with both anatomically modern humans ("Homo sapiens") 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.
Middle Stone Age
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".