“…Inkjet printing and PCR are both door-opening in this way, but stents are not. Even if people generally agree that technology evolves, there is controversy about whether the evolution of technology is in some interesting sense "Darwinian" or "adaptive" [1,12,15,22,25,30,42]. Much of the same controversy arises in connection with cultural evolution in general [13,14,35], and especially in connection with so-called memetics [2,17,18].…”