Subject: Could indian pipes have dropped photosynthesis through evolution?

Today, our lesson in biology began with evolutionary history of bacteria and 
photosynthesis.  Bacteria only became photosynthetic because they were lacking 
food due to an over abundance of bacteria. My question is can this process go 
backwards and could food be so over abundant that plants would no longer need 
photosythesis? and through evolution did the indian pipe plant adapt to the 
over abundance of food around its roots and therefore grow roots to take in 
food by other means than photosynthesis or has it always done this without 
some sort of evolutionary change. Also, could the indian pipe have adapted to 
having no sunlight therefore by evolution transformed itself to be saprophytic?

Re: Could indian pipes have dropped photosynthesis through evolution?