The theory of biogenesis states that a living organism arises from another living organisms.
*Experimental evidence of chemical evolution/Miller’ experiment**
- Experiment was performed by *.L. Miller and H.C. Urey in 1953.
- Experimental set-up: In a closed flask containing CH4, H2, NH3 and water vapour at 800°C, electric discharge was created. The conditions were similar to those in primitive atmosphere.
- Observations: After a week, they observed presence of amino acids and complex molecules like sugars, nitrogen bases, pigments and fats in the flask.
Conclusions:
(i) It provides experimental evidence for the theory of chemical origin.
(ii) It showed that the first non-cellular form of life was created about 3 billion years ago.
(iii) It showed that non-cellular biomolecules exist in the form of DNA, RNA, polysaccharides and protein.
