Mg-driven selection of natural phosphatidic acids in primitive membranes.

Biological membranes are composed exclusively of phospholipids comprising glycerol-1-phosphate or glycerol-3-phosphate. By contrast, primitive membranes would have likely been composed of heterogeneous mixtures of phospholipids, including non-natural analogues comprising glycerol-2-phosphate, as delivered by prebiotic synthesis. Thus, it is not clear how the selection of natural phospholipids could have come about.