Worms (C. elegans specifically) have specific well-documented responses to certain stimuli. You can apply those same stimuli to your simulated worm and see if it responds like a typical real worm.
Actually that's pretty much what they are. There us a whole battery of stimulus stimulus-response tests that are essentially used as a regression test suite to figure out what deleterious (or even beneficial) effect a given mutation has. Of course these "tests" must be manually carried out by researchers on live worms.
