ORIGIN OF LIFE ON EARTH

Origin of life on Earth

There are some hipotheses about the origin of life in our planet:

-1920: The Oparin-Handale hypothesis´s steps are:

           1) The formation of organic molecules from inorganic compounds.

           2) The formation of polymers of organic molecules

           3) The formation of protocells with a semi-permeable membrane  

 since organic molecules and polymers.

-1950: Miller-Urey experiment: They tested and confirmed the first step of Oparin-Handale hypothesis.

-2006: Organic molecules from meteors: Many scientists think that extra-terrestrial organic matter contributed with the formation of organic molecules on earth began. Bernstein propouse the 3 major sources of pre-life Earth´s organic molecules.

             A- Atmospheric synthesis by Miller-Urey chemistry.

             B- Synthesis at deep sea hydrothermal vents.

             C- In-fall of organic molecules from the outer space.

-The RNA world hypothesis: The  discovery that RNA molecules could both encode hereditary information and catalyse their own replication led Thomas Cech to a Nobel prize.

-Protocells hypothesis: Rudimentary cells with self replicating and metabolic enzymes (catalytic RNA molecules) contained by a semi-permeable membrane are more efficiently.