From Bacteria to Bach and Back: The Evolution of Minds

by Daniel C. Dennett

How does Nature debug its designs? Since there is no source code or comments to read, there can be no debugging by brilliant intellectual explanation; design revision in Nature must follow the profligate method of releasing and test-driving many variants and letting the losers die, unexamined. This won’t necessarily find the globally optimal design but the best locally accessible versions will thrive, and further test-driving will winnow the winners further, raising the bar slightly for the next generation.20 Evolution is, as Richard Dawkins’s (1986) memorable title emphasizes, the Blind Watchmaker, and given the R&D method used, it is no wonder that evolution’s products are full of opportunistic, short-sighted, but deviously effective twists and turns—effective except when they aren’t!