A program is more like a steam engine that a building. More like the immune system than an outhouse, or a skyscraper. A system is more like a city than a doghouse, or, for than matter, an ocean liner.
Organs have multiple functions for the same reasons towns due. It’s literally natural for them to do so.
Only planned towns have a single function. Company towns are dreary places to live. Do I live in one?
What is the analog to sexual selection in our area: feature-itis perhaps?
