Summary
The climatic events of the Great Ice Age (the Pleistocene) between about 1.8 million and 15¸000 years ago saw complex fluctuations between glacial maxima and much shorter interglacial periods that were the backdrop to the evolution not only of Homo erectus¸ but of modern humans–Homo sapiens sapiens– as well. Homo erectus had evolved from earlier Homo in tropical Africa by 1.9 million years ago¸ at about the same time that fire was tamed¸ then radiated into Europe and Asia as part of a general radiation of mammalian species soon afterward. The new humans used a simple technology based on hand axes and basic flake technology in the west¸ relying heavily on bamboo and other forest products in Southeast Asia. There was a gradual increase in brain size¸ perhaps beginning as early as about 0.4 million years ago¸ as archaic forms of Homo sapiens with enlarged brain capacities evolved in various parts of the Old World. The best known of these forms are the Neanderthals of Europe and Eurasia¸ who developed more sophisticated toolmaking technology than Homo erectus¸ were adept hunters and foragers¸ and were the first humans to bury some of their dead.
Two competing theories account for the appearance of anatomically modern humans. The Out–of–Africa hypothesis argues that modern humans evolved in tropical Africa before 100¸000 years ago¸ then spread into parts of the world from Southwest Asia after 45¸000 years ago. The Multi–regional hypothesis has it that modern humans developed independently in Africa¸ Europe¸ and Asia¸ and that the biological diversity of contemporary humankind has very deep roots in prehistory. With the appearance of modern humans¸ the long prehistory of the archaic world ends.
