biggs:
Cooper: Any time you swap out a song writer the band changes. I agree though, if the bass player isn't doing any writing then there won't be that much of a difference.
Coop- what constitutes "writing"? If I write a song on guitar and bring it to our band and you work out the bass line for it, does that mean you are "writing"? Or do you consider "writing" just the act of bringing a song to the band...the initial creation.
I'll answer this with a very ambiguous, it depends. If you brought in a "finished" song and all I did was write a bassline it may not matter, but if you brought in a couple of riffs and I had direct influence in writing bridges and arranging the song that would certainly change it to a certain degree. In fact the final product might not be what you heard in your head, but you might like the outcome more than you were anticipating. Sometimes songs end up being completely different based on what other members of the band add. Drummers obviously play in greatly to the feel, and bass players can dictate the key signature if the guitar is playing hollow chords. It really is subjective.
Immitation is the best form of flatery.