However, in the case of phospholipids, a case of dual homochirality is known with archaeal membranes being based on sn-glycerol 1-phosphate (G1P), i.e., enantiomers with stereochemistry S, while bacteria and eukaryotes on sn-glycerol-3-phosphate (G3P), i.e., enantiomers with stereochemistry R . This phenomenon of different homochirality of phospholipids that exist in nature is known as the lipid divide. Archaea and bacteria, the two fundamental domains of life, share a common ancestor, called the last universal common ancestor (LUCA) . The reason why the split occurred is still unknown, and several theories have addressed this issue, including that the LUCA membrane was heterochiral or racemic and that instability between the two phospholipid enantiomers eventually led to lipid partitioning . However, the robustness of cells with a hybrid heterochiral lipid membrane has been reported to be higher than that of cells with a homochiral lipid membrane . The LUCA membrane could be homochiral, see articles Yokobori et al., or it could also be achiral.