70,000 years ago, an explosion of innovations began, not only in tools but also in aspects of life unknown to previous hominids: art, religion, and ocean navigation. Some anthropologists call this event the Big Bang. Here was something new in the world: human culture, changing incomparably faster than the slow biological evolution of species. We know much more about the material culture of modern humans than about that of their predecessors because modern humans created far more things and because many of the things they made out of organic matter—bones, antlers, hides, and wood—have survived over the past 70,000 years, especially in cold places where earlier creatures would not have ventured. Consider just one kind of tool, the sharp-edged stone. Modern humans made a great variety of tools for cutting, scraping, and piercing, even burins or chisels used to engrave fi ne lines on antler and bone. They even made microliths, tiny pieces of sharp stone that they embedded in a bone or wooden haft to form a saw. One anthropologist calculated how much cutting edge hominids were able to get from a one-pound piece of flint. Homo habilis, 2 million years ago, could break off a flake, leaving three inches of cutting edge; Homo erectus, 300,000 years ago, could obtain eight to twelve inches from the hand axe and the fl akes; a Neanderthal, 100,000 years ago, could obtain 30 to 40 inches of cutting edge; by 30,000 years ago, a skilled hunter could turn that pound of fl int into 30 to 40 feet of blades (Source: Technology, A World History).