"Can a Systems Biologist Fix a Tamagotchi?" L. Cardelli

''Biologists cannot under-stand radios without any knowledge of electrical engineering but, similarly, electrical engineers can not understand mp3 players without any knowledge of software engineering, even though mp3 players play music just like radios.
As it turns out, even the simplest biological organisms have a minimum of hundreds of kilobytes of software, in the form of digitally stored genetic information, and can have as much as several megabytes of it (considerably more than mp3 players). There is no life form that is just hardware circuits; not even viruses, which on the contrary are almost purely software. The role of such genetic software is commonly understood as that of “running the organism”.'' [pdf]