First forms of life, which lacked the ability to synthesize their own nutrients.
Depend on outside food sources.
Origin of Life Building Blocks
Simple inorganic and organic compounds (in primitive seas) such as salts, methane, ammonia, hydrogen, and water.
Energy was present in the form of heat, electricity, solar radiation, including X-rays and ultraviolet light, cosmic rays and radioactivity.
Sugars, amino acids, purines, and pyrimidines.
After many years, these simple monomeric molecules combined to form a supply of macromolecules.
Evidence of Organic Synthesis
1953, Stanley L. Miller. UV radiation, heat or a combination of these to a mixture of methane, hydrogen, ammonia, and water could result in the formation of complex organic compounds. The 4 gases were continuously circulated past electrical discharges from tungsten elctrodes.
Organic compounds formed = urea, hydrogen, cyanide, acetic acid, and lactic acid
Formation of Primitive Cells
Coacervate droplets absorb and incorporate substances from environment, as well as have a definite internal structure. Developed on early earth and had properties normally associated with living organisms.
Few % turned into 1st primitive cells which had nucleic acid polymers and became capable of reproduction.
Life would have ceased to exist if not developed.
1st Autotrophs developed primitive photosynthetic pathways using solar energy to made carbohydrates from CO2 and water (O2 waste product).