I think you miss the point. Every scrap of membrane in every cell in every known organism -- and cells have a lot of different membranes in them -- was once par

I think you miss the point. Every scrap of membrane in every cell in every known organism -- and cells have a lot of different membranes in them -- was once part of a membrane in the parent cell, or was one of several in a parent cell that became part of this or that daughter cell. We don't know of any organism that constructs any membrane for any purpose de novo. In a very real sense, life may be defined as a membrane with apparatus to aid in growing it. So, in that sense, every evolutionary change is ultimately a refinement to enable growing more membrane. You, personally, are a lot of membranes all folded and wrapped up and carrying around a skeleton.