no1tovote4
Gold Member
deaddude said:because if the were not growing at the bottom of the thrench then the lowest point in the ocean would remain the same.
If you are saying that the material which makes the sponges up would be removed from the ocean then the volume of the ocean would change and location would not matter.
Even if the sponges did not grow the volume of the ocean would remain the same. The sponges could not grow without the material being available to begin with, it does not spontaneously appear. Therefore when a sponge grows it takes nothing from the volume, nor adds to the volume of the ocean and would effect nothing if sponges had never evolved.