Origin of Life in the Oceans 



A. I. OPARIN 



A. N. Bach Institute of Biochemistry, Academy of Sciences of the 

 Union of Soviet Socialist Republics, Moscow 



ALL attempts to prove spontaneous generation of life directly 

 from inorganic matter either under natural or laboratory conditions 

 have been in vain. It is more and more evident that the origin of 

 life on the earth could have taken place only as an integral part 

 in the overall development of our planet. Available data show that 

 the origin of life represents a long-term, one-sided process toward 

 increasingly complex organic substances and of complex open 

 systems synthesized from these. 



We certainly cannot reproduce the whole process of the origin 

 of life, which took place over a period of billions of years, in the 

 same form as it took place in nature. We can study only isolated 

 steps in this process either under natural conditions when they 

 have remained as they were at the time the earth was devoid of 

 life or under artificial conditions reproduced in our laboratories. 



On the basis of all our knowledge, three chief stages essential to 

 the origin of life may be outlined provisionally. The first is the 

 primary (abiogenetical) formation of the simplest organic sub- 

 stances, hydrocarbons and their closest oxygen, nitrogen, sulfur 

 and phosphorus derivatives. The second is the conversion of these 

 substances, basic for the synthesis of the most complex organic 

 compounds characteristic of life, proteins, nucleic acids, porphy- 

 rins, lipids, etc. Finally, the third stage is the formation of multi- 

 molecular complexes, open systems, from the latter compounds. 

 Subsequently, they are converted into primitive living organisms. 



The development of the first of these stages is closely associated 

 with the planetary cosmogony itself. The emergence of the 

 simplest organic substances must have taken place during the 

 formation of the earth and in the early stages of its development. 



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