The Miller–Urey apparatus supplied energy to methane (CH₄), ammonia (NH₃), hydrogen (H₂) and water vapour (H₂O), producing organic molecules including amino acids. This experimental mixture is a model; the exact ancient atmosphere remains a scientific question. Proteinoid microspheres are nonliving, selectively permeable cell-like compartments.

The model has a domain of validity. Explain its assumptions before using it in a changed context, then compare your prediction with evidence.

• Early Earth differed from today. Chemical-origin experiments explore how nonliving chemistry can produce building blocks; they do not demonstrate the creation of life.
• Organic does not mean alive. Microspheres and amino acids are not complete organisms.