OK, I just have layman's questions. A diatom has a silica valve made up of two walls made of glass (sand) and I am guessing the valve sifts water for nourishment and wastes for the organic part of the diatom. I never knew that inorganic and organic materials together existed to make a living plant or animal. Is inorganic and organic combinations in life forms a rare thing or is it common? Wouldn't that be the unlikely prospect of a human heart having a glass valve? I wonder why a diatom evolved this way?
