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.
Iron Age
In South Asia, the Iron Age is taken to begin with the ironworking Painted Gray Ware culture and to end with the reign of Ashoka (3rd century BC). The use of the term "Iron Age" in the archaeology of South, East and Southeast Asia is more recent, and less common, than for western Eurasia; at least in China prehistory had ended before iron-working arrived, so the term is infrequently used. The Sahel (Sudan region) and Sub-Saharan Africa are outside of the three-age system, there being no Bronze Age, but the term "Iron Age" is sometimes used in reference to early cultures practicing ironworking such as the Nok culture of Nigeria.
Increasingly the Iron Age in Europe is being seen as a part of the Bronze Age collapse in the ancient Near East, in ancient India (with the post-Rigvedic Vedic civilization), ancient Iran, and ancient Greece (with the Greek Dark Ages). In other regions of Europe the Iron Age began in the 8th century BC in Central Europe and the 6th century BC in Northern Europe. The Near Eastern Iron Age is divided into two subsections, Iron I and Iron II. Iron I (1200–1000 BC) illustrates both continuity and discontinuity with the previous Late Bronze Age. There is no definitive cultural break between the 13th and 12th centuries BC throughout the entire region, although certain new features in the hill country, Transjordan and coastal region may suggest the appearance of the Aramaean and Sea People groups. There is evidence, however, of strong continuity with Bronze Age culture, although as one moves later into Iron I the culture begins to diverge more significantly from that of the late 2nd millennium.