[Elsie]

Be that as it may, comparing language development to human evolution is kind of silly.

Why??

Wouldn't your same rules apply??

WhAt is slang but mutations in the word streaM?

There must be SOME 'selection process' that accepts and keeps new words and drops older ones.

[Modernman]

Wouldn't your same rules apply??

Not really. A lot of language is consciously and intentionally designed.