In addition, Australia’s aridity, infertility, and climatic unpredictability limited its hunter-gatherer population to only a few hundred thousand people. Compared with the tens of millions of people in ancient China or Mesoamerica, that meant that Australia had far fewer potential inventors, and far fewer societies to experiment with adopting innovations.

Social Structure. Almost all species of domesticated large mammals prove to be ones whose wild ancestors share three social characteristics: they live in herds; they maintain a well-developed dominance hierarchy among herd members; and the herds occupy overlapping home ranges rather than mutually exclusive territories. ... In that way, many adults can coexist in the herd without constant fighting and with each knowing its rank. That social structure is ideal for domestication, because humans in effect take over the dominance hierarchy.

A simple example is the spread of muskets among New Zealand’s Maori tribes. One tribe, the Ngapuhi, adopted muskets from European traders around 1818. Over the course of the next 15 years, New Zealand was convulsed by the so-called Musket Wars, as musketless tribes either acquired muskets or were subjugated by tribes already armed with them.

But the question for our purposes is whether the broad pattern of world history would have been altered significantly if some genius inventor had not been born at a particular place and time. The answer is clear: there has never been any such person. All recognized famous inventors had capable predecessors and successors and made their improvements at a time when society was capable of using their product.

At the one end lies “blueprint copying,” when you copy or modify an available detailed blueprint. At the opposite end lies “idea diffusion,” when you receive little more than the basic idea and have to reinvent the details. Knowing that it can be done stimulates you to try to do it yourself, but your eventual specific solution may or may not resemble that of the first inventor.

Still other devices, invented to serve one purpose, eventually found most of their use for other, unanticipated purposes. It may come as a surprise to learn that these inventions in search of a use include most of the major technological breakthroughs of modern times, ranging from the airplane and automobile, through the internal combustion engine and electric light bulb, to the phonograph and transistor. Thus, invention is often the mother of necessity, rather than vice versa.

For thousands of years before it jelled, people in some farming villages of the Fertile Crescent had been using clay tokens of various simple shapes for accounting purposes, such as recording numbers of sheep and amounts of grain. In the last centuries before 3000B.C., developments in accounting technology, format, and signs rapidly led to the first system of writing.