Prehistoric technology Ground and polished stone tools continued to be created and used during the Neolithic period. Numeric record keeping evolved from a system of counting using small clay tokens that began in Sumer about 8000 BC. The Stone Age developed into the Bronze Age after the Neolithic Revolution. The Neolithic Revolution involved radical changes in agricultural technology which included development of agriculture, animal domestication, and the adoption of permanent settlements. The Bronze Age is characterised by metal smelting of copper and its alloy bronze, an alloy of tin and copper, to create implements and weapons. Polished stone tools continued to be
Neolithic Europe for many centuries, with ongoing gradual admixture throughout the 5th to 4th millennia BC (rather than a single admixture event on initial contact). Admixture rates varied geographically; in the late Neolithic, WHG ancestry in farmers in Hungary was at around 10%, in Germany around 25% and in Iberia as high as 50%. There is no direct evidence of the languages spoken in the Neolithic. Some proponents of paleolinguistics attempt to extend the methods of historical linguistics to the Stone Age, but this has little academic support. Criticising scenarios which envision for the Neolithic only a small number of language families