Panda writes:
Yes, but what causes words to be selected in?
As I said, usage. People use the words that get their message across with minimum confusion, the words that are easiest to pronounce, the words that they like the sound of, etc. just as predators eat the animals that are easy to catch, that taste good, etc. The only difference is that one is positive selection and the other is negative selection.
"I'm Rory Bellows, I tell you! And I got a lot of corroborating evidence... over here... by the throttle!"