I agree to RedFred. The native life is one of the basic part of the game and if you dont put your industrial waste in the world the mindworms wont hurt you.
You should playe the game *with* them, not *against* them. And trust me (in MP) if someone benefits from the native life and you don't do that too, you will loose a *great* option! Last but not least you put Dierde and Cha Dawn to Death because their special capabilities are on that site.
But if you still want to play without the story

than try to play with the scenario editor and the alpha.txt - maybe there is a possibility - but never used it (and never will).
Sorry, friend...