PDP-11s were around before Apples, but no way I could haul them around in my pocket or bag. The battery pack (or extension cord) alone would crush me. Likewise look at the illustration of mouse evolution: http://www.newyorker.com/images/2011/05/16/p465/110516_r20860_p465.jpg From Gladwell's story in The New Yorker Reduction in number of buttons for commands, size, cost, failure rate... Incremental change yet... People could grow bacteria long before genetic engineering. A boombox isn't an iPod etc., etc.