Diamond views invention as basically an accretive process. People seldom invent technologies from scratch, and many of the most important technologies, the steam engine, for example, have been adapted from earlier models:
Edison's famous "invention" of the light bulb...improved on many other incandescent light bulbs patented by many other inventors between 1841 and 1878...Samuel Morse's telegraph was preceded by those of Joseph Henry, William Cooke, and Charles Wheatstone; and Eli Whitney's cotton gin...extended gins that had been cleaning long-staple...cotton for thousands of years.
Additionally, these inventions were also put to uses far different from their original intent. Otto's gasoline engine was almost useless, but it did inspire Gottfried Daimler to put it to use as an engine for an automobile; and James Watt's steam engine,itself adapted from a Thomas Newcomen invention, was originally intended to drive pumps, not locomotives or mill equipment. So invention is not as important as the ability to adapt inventions for profitable use.
Source: Jared Diamond, Guns, Germs, and Steel: The Fates of Human Societies (New York: W.W. Norton and Company, 1999), 245.