Stone Age

The Stone Age was a broad prehistoric period during which stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended between 4000 BC and 2000 BC, with the advent of metalworking. Because of its enormous timescale, it encompasses 99% of human history.
Though some simple metalworking of malleable metals, particularly the use of gold and copper for purposes of ornamentation, was known in the Stone Age, it is the melting and smelting of copper that marks the end of the Stone Age. In Western Asia, this occurred by about 3000 BC, when bronze became widespread. The term Bronze Age is used to describe the period that followed the Stone Age, as well as to describe cultures that had developed techniques and technologies for working copper alloys into tools, supplanting stone in many uses.
Stone Age artifacts that have been discovered include tools used by modern humans, by their predecessor species in the genus Homo, and possibly by the earlier partly contemporaneous genera Australopithecus and Paranthropus. Bone tools have been discovered that were used during this period as well but these are rarely preserved in the archaeological record. The Stone Age is further subdivided by the types of stone tools in use.
The Stone Age is the first period in the three-age system frequently used in archaeology to divide the timeline of human technological prehistory into functional periods, with the next two being the Bronze Age and the Iron Age, respectively. The Stone Age is also commonly divided into three distinct periods: the earliest and most primitive being the Paleolithic era; a transitional period with finer tools known as the Mesolithic era; and the final stage known as the Neolithic era. Neolithic peoples were the first to transition away from hunter-gatherer societies into the settled lifestyle of inhabiting towns and villages as agriculture became widespread. In the chronology of prehistory, the Neolithic era usually overlaps with the Chalcolithic era preceding the Bronze Age.
The Archaeology of the Americas uses different markers to assign five periods which have different dates in different areas; the oldest period is the similarly named Lithic stage.

Historical significance

The Stone Age is contemporaneous with the evolution of the genus Homo, with the possible exception of the early Stone Age, when species prior to Homo may have manufactured tools. According to the age and location of the current evidence, the cradle of the genus is the East African Rift System, especially toward the north in Ethiopia, where it is bordered by grasslands. The closest relative among the other living primates, the genus Pan, represents a branch that continued on in the deep forest, where the primates evolved. The rift served as a conduit for movement into southern Africa and also north down the Nile into North Africa and through the continuation of the rift in the Levant to the vast grasslands of Asia.
Starting from about 4 million years ago a single biome established itself from South Africa through the rift, North Africa, and across Asia to modern China. This has been called "transcontinental 'savannahstan recently. Starting in the grasslands of the rift, Homo erectus, the predecessor of modern humans, found an ecological niche as a tool-maker and developed a dependence on it, becoming a "tool-equipped savanna dweller".

Stone Age in archaeology

Beginning of the Stone Age

The oldest indirect evidence found of stone tool use is fossilised animal bones with tool marks; these are 3.4 million years old and were found in the Lower Awash Valley in Ethiopia. Archaeological discoveries in Kenya in 2015, identifying what may be the oldest evidence of hominin use of tools known to date, have indicated that Kenyanthropus platyops may have been the earliest tool-users known.
The oldest stone tools were excavated from the site of Lomekwi 3 in West Turkana, northwestern Kenya, and date to 3.3 million years old. Prior to the discovery of these "Lomekwian" tools, the oldest known stone tools had been found at several sites at Gona, Ethiopia, on sediments of the paleo-Awash River, which serve to date them. All the tools come from the Busidama Formation, which lies above a disconformity, or missing layer, which would have been from 2.9 to 2.7 mya. The oldest sites discovered to contain tools are dated to 2.6–2.55 mya. One of the most striking circumstances about these sites is that they are from the Late Pliocene, where prior to their discovery tools were thought to have evolved only in the Pleistocene. Excavators at the locality point out that:
The species that made the Pliocene tools remains unknown. Fragments of Australopithecus garhi, Australopithecus aethiopicus, and Homo, possibly Homo habilis, have been found in sites near the age of the Gona tools.
In July 2018, scientists reported the discovery in China of what may possibly be, if confirmed, the oldest known stone tools outside Africa, estimated at 2.12 million years old.

End of the Stone Age

Innovation in the technique of smelting ore is regarded as the end of the Stone Age and the beginning of the Bronze Age. The first highly significant metal manufactured was bronze, an alloy of copper and tin or arsenic, each of which was smelted separately. The transition from the Stone Age to the Bronze Age was a period during which modern people could smelt copper, but did not yet manufacture bronze, a time known as the Copper Age. The Chalcolithic by convention is the initial period of the Bronze Age. The Bronze Age was followed by the Iron Age.
The transition out of the Stone Age occurred between 6000 and 2500 BC for much of humanity living in North Africa and Eurasia.
The first evidence of human metallurgy dates to between the 6th and 5th millennia BC in the archaeological sites of the Vinča culture, including Majdanpek, Jarmovac, Pločnik, Rudna Glava in modern-day Serbia.
Ötzi the Iceman, a mummy from about 3300 BC, carried with him a copper axe and a flint knife.
In some regions, such as Sub-Saharan Africa, the Stone Age was followed directly by the Iron Age. The Middle East and Southeast Asian regions progressed past Stone Age technology around 6000 BC. Europe, and the rest of Asia became post-Stone Age societies by about 4000 BC. The proto-Inca cultures of South America continued at a Stone Age level until around 2000 BC, when gold, copper, and silver made their entrance. The peoples of the Americas notably did not develop a widespread behavior of smelting bronze or iron after the Stone Age period, although the technology existed. Stone tool manufacture continued even after the Stone Age ended in a given area. In Europe and North America, millstones were in use until well into the 20th century, and still are in many parts of the world.

Concept of the Stone Age

The terms "Stone Age", "Bronze Age", and "Iron Age" are not intended to suggest that advancements and time periods in prehistory are only measured by the type of tool material, rather than, for example, social organization, food sources exploited, adaptation to climate, adoption of agriculture, cooking, settlement, and religion. Like pottery, the typology of the stone tools combined with the relative sequence of the types in various regions provide a chronological framework for the evolution of humanity and society. They serve as diagnostics of date, rather than characterizing the people or the society.
Lithic analysis is a major and specialised form of archaeological investigation. It involves the measurement of stone tools to determine their typology, function and technologies involved. It includes the scientific study of the lithic reduction of the raw materials and methods used to make the prehistoric artifacts that are discovered. Much of this study takes place in the laboratory in the presence of various specialists. In experimental archaeology, researchers attempt to create replica tools, to understand how they were made. Flintknappers are craftsmen who use sharp tools to reduce flintstone to flint tool.
In addition to lithic analysis, field prehistorians use a wide range of techniques derived from multiple fields. The work of archaeologists in determining the paleocontext and relative sequence of the layers is supplemented by the efforts of geologic specialists in identifying layers of rock developed or deposited over geologic time; of paleontological specialists in identifying bones and animals; of palynologists in discovering and identifying pollen, spores and plant species; of physicists and chemists in laboratories determining ages of materials by carbon-14, potassium-argon and other methods. The study of the Stone Age has never been limited to stone tools and archaeology, even though they are important forms of evidence. The chief focus of study has always been on the society and the living people who belonged to it.
Useful as it has been, the concept of the Stone Age has its limitations. The date range of this period is ambiguous, disputed, and variable, depending upon the region in question. While it is possible to speak of a general 'Stone Age' period for the whole of humanity, some groups never developed metal-smelting technology, and so remained in the so-called 'Stone Age' until they encountered technologically developed cultures. The term was innovated to describe the archaeological cultures of Europe. It may not always be the best in relation to regions such as some parts of the Indies and Oceania, where farmers or hunter-gatherers used stone for tools until European colonisation began.
File:Kiuruveden reikäkirves - Stone axe of Kiuruvesi.jpg|thumb|upright=.7|Stone Age hand axe engraved with human face found from Kiuruvesi, Finland
Archaeologists of the late 19th and early 20th centuries CE, who adapted the three-age system to their ideas, hoped to combine cultural anthropology and archaeology in such a way that a specific contemporaneous tribe could be used to illustrate the way of life and beliefs of the people exercising a particular Stone-Age technology. As a description of people living today, the term Stone Age is controversial. The Association of Social Anthropologists discourages this use, asserting:

To describe any living group as 'primitive' or 'Stone Age' inevitably implies that they are living representatives of some earlier stage of human development that the majority of humankind has left behind.