  Many signs indicate that the graphene could widely occur on the early Earth.
Here, we report a new theory that graphene might be an embryo of protocell
membrane, and found several evidences. Firstly, the graphene oxide and
phospholipid-graphene oxide composite would curl into capsules in strongly
acidic saturated solution of Pb(NO3)2 at low temperature, providing a
protective space for biochemical reactions. Secondly, L-animi acids exhibit
higher reactivity than D-animi acids for graphene oxides in favor of the
formation of left-handed proteins. Thirdly, monolayer graphene with nanopores
prepared by unfocused 84Kr25+ has high selectivity for permeation of the
monovalent metal ions (Rb+ > K+ > Cs+ > Na+ > Li+), but does not allow Cl-
through, which could be attributed to the ion exchange of oxygen-containing
groups on the rim of nanopores. It is similar to K+ channels, which would cause
efflux of some ions from capsule of graphene oxides with the decrease of pH in
the primitive ocean, creating a suitable inner condition for the origin of
life. Consequently, the strongly acidic, high salinity and strong radiation as
well as temperature changes in the early Earth, regarded as negative factors,
would be indispensable for the origin of protocell. In short, graphene bred
life, but digested gradually by the evolution.

Populations and Evolution;Soft Condensed Matter;Biological Physics