text: * Archaeology: Prehistoric Archaeology\n    * Cave Dwellers\n\nmore...\nEncarta Search\nSearch Encarta about Stone Age\nUpgrade your Encarta Experience\nSpend less time searching and more time learning.\nLearn more\n\nK-12 Success\n\nK-5 Parents\n\nHomework Help\n\nOnline Tutoring\n\nCollege-Grad\n\nCollege Prep\n\n2006 Rankings\n\nGrad & Biz\n\nAdult Learning\n\nOnline Degrees\n\nCareer Training\n\nFree Classes\n\nStone Age, period of human technological development characterized by the use of stone as the principal raw material for tools. In a given geographic region, the Stone Age normally predated the invention or spread of metalworking technology. Human groups in different parts of the world began using stone tools at different times and abandoned stone for metal tools at different times. Broadly speaking, however, the Stone Age began roughly 2.5 million years ago, ended in some parts of the world 5,000 years ago, and ended in other regions much more recently. Today only a few isolated human populations rely largely on stone for their technologies, and that reliance is rapidly vanishing with the introduction of tools from the modern industrialized world.\n\nHuman ancestors living before the Stone Age likely used objects as tools, a behavior that scientists find today among chimpanzees. Wild chimpanzees in Africa exhibit a range of tool-using behaviors. For example, they use bent twigs to fish for termites, chewed wads of leaves to soak up liquid, and branches and stones as hammers, anvils, missiles, or clubs. However, when prehistoric humans began to make stone tools they became dramatically distinct from the rest of the animal world. Although other animals may use stone objects as simple tools, the intentional modification of stone into tools, as well as using tools to make other tools, appear to be behaviors unique to humans. This stone toolmaking and tool-using behavior became central to the way early humans adapted to their environment and almost certainly had a profound effect on human evolution.\n\nArchaeologists believe the Stone Age began about 2.5 million years ago because that marks the age of the earliest stone tool remnants ever discovered. The earliest recognizable stone artifacts mark the beginnings of the archaeological record—that is, the sum total of material remnants of ancient human activities. As recently as 5,000 years ago all human societies on the face of the earth were essentially still living in the Stone Age. Therefore, over 99.8 percent of humans’ time as toolmakers—from 2.5 million years ago to 5,000 years ago—took place during the Stone Age. During the Stone Age our ancestors went through many different stages of biological and cultural evolution. It was long after our lineage became anatomically modern that we began to experiment with new innovations such as metallurgy, heralding the end of the Stone Age.\nII\nStudy of the Stone Age\n\nThe term Stone Age has been used since the early 1800s as a designation for an earlier, prehistoric stage of human culture, one in which stone rather than metal tools were used. By the early 1800s various archaeological sites had been found in Europe that contained mysterious items from evidently earlier, prehistoric times. Christian Thomsen, curator of the National Museum in Copenhagen, Denmark, developed a classification scheme to organize the museum’s growing collections into three successive technological stages in the human past: Stone Age, Bronze Age, and Iron Age. This three-age classification was quickly adopted and spread not only among museums in Europe but also among excavators, who were able to identify Stone Age remnants that were found below Bronze Age remnants, which were in turn found below Iron Age remnants as they dug down through layers of deposits at their sites. The fact that Stone Age remnants were found at the bottom layers indicated that they were the oldest.\n\n\nThe study of the Stone Age falls under the fields of anthropolog