The period from 2.7‐2.58 Million years ago (Mya) encompasses the first use of stone tools in Gona, Ethiopia and its spread andwidespread use elsewhere soon thereafter. It ends with the development of agriculture, the domestication of certain animals, and the smelting of copper ore to produce metal. It is termedprehistoric since humanity had not yet started writing—the traditional start of history (i.e., recorded history).
It is the first age in the three-age system. A division of the Stone Ageinto older and younger parts was first proposed by Jens Jacob Worsaae in 1859 through his work with Danish kitchen middens that began in 1851. The subdivision into the Palaeolithic,Mesolithic and Neolithic periods that still is in use today, was made by John Lubbock in his now classic 1865 book Pre-historic Times. These three periods are further subdivided. In reality, thesuccession of phases varies enormously from one region (and culture) to another, indeed, humanity continued to expand into new areas even during the metal ages. Therefore, it is better tospeak of a Stone Age, instead of the Stone Age. As a description of people living today, the term stone age is controversial. The Association of Social Anthropologists discourages this use.