Created through human artifice but not merely by manipulating a natural living organism (such as a bacterium), a protocell is a self-assembling and self-reproducing chemical system, with the following three properties: |
1. It maintains its identity over time by spatially localizing its components in some form of container. |
2. It utilizes free energy from its environment and digests environmental resources in order to maintain itself, grow, and ultimately reproduce. This use of energy and materials is a form of metabolism. |
3. The containment and metabolism are under the control of replicable and inheritable chemical information that can be “mutated” when the protocell reproduces. This informational chemistry functions as a programmable genetic system. |
The proper chemical integration of these three properties enables protocells to reproduce themselves, and a population of them could adapt and evolve by natural selection. |