Question

Q. What evidence do we have for origin of life from inanimate matter ?

Answer 1

Dear Student, ​Origin of life from inanimate matter was first proposed by Alexander Oparin & J.B.S Haldane. According to them, the inorganic molecules present in the primitive atmosphere combined to form simple organic compounds such as sugars, fatty acids, glycerol, amino acids, nitrogen bases etc. With further cooling of the earth, the simple organic compounds combined to form complex compounds.These complex organic compounds accumulated in the sea water making it a sort of “primordial soup”. In this sea water, large molecules aggregated and formed an envelope of water around them, these aggregates are called coacervates.The envelope of water around these coacervates increased the chances of chemical reactions.Gradually, they started breaking down, building up and even multiplying by taking up new materials from the ocean and releasing the degraded materials. Therefore, coacervates exhibited the basic properties of life such as metabolism, growth and reproduction. Gradually, nucleic acids took the precise control of coacervates and transferred them into protobionts (the first living systems). Later, these protobionts got enclosed in a protein lipid membrane for increasing their survival. The basic properties of life exhibited by the protobionts became regular, precise and controlled leading to the formation of first cells. They are believed to be anaerobic (as developed in oxygen-free atmosphere) and obtain energy by the fermentation of organic compounds. Much later, autotrophs in the form of blue green algae arose which changed the situation and released free molecular oxygen in the atmosphere. This Oparin -Haldane hypothesis was proved by Urey- Miller in 1953. They conducted an experiment in which they created an atmosphere containing CH4 , H2, H2O, and NH3 in a reaction vessel. Next, they ran a continuous electric current through the system, to simulate lightning, resulting in the production of several small organic molecules including urea, hydrogen cyanide, acetic acid and amino acids. These amino acids are the building blocks of proteins in living cells. Hence this shows that life originated from inanimate matter. Regards