Life is unique and complex Organization of chemical molecules which can express itself chemically. How life originated on earth is still not having suitable answer. Different biologists have proposed different theories for the origin of life. The major theories for the origin of life are:
*Theory
of special creation
*Theory
of spontaneous generation or Abiogenesis
*
Theory of biogenesis
*
The cosmozoic theory or theory of Panspermia
*
The catastrophic theory
* Modern theory or Biochemical theory or Oparin- Haldane theory