2 A. I. OPARIN 



the whole course of the development of matter which preceded this origin. Life 

 is not separated from the inorganic world by an impassable gulf — it arose as a 

 new quality during the process of the development ofthat world. An evolutionary 

 approach to the study of our problem will, therefore, open up a wider vista of 

 possibilities for its solution. 



The advances in present-day science, the rich store of facts which are now at 

 the disposal of astronomers, physicists, geologists, chemists and biologists, enable 

 us to draw, with some degree of verisimilitude, a picture of the evolutionary 

 development of matter which took place at some time on our planet, and to point 

 out the possible stages through which this development could have passed on 

 the way to the emergence of life. 



We must suppose that, as the first stage, there were present, on the still lifeless 

 Earth, the simplest organic compounds, the hydrocarbons and their closest 

 derivatives. The succeeding increase in complexity of these compounds, which 

 occurred abiogenically in the lithosphère, atmosphere and hydrosphere of our 

 planet, in accordance with the general laws of physics and chemistry, may be 

 regarded as the second stage in this development. This process resulted in the 

 appearance of very complicated organic substances of high molecular weight, in 

 particular, substances resembling proteins, nucleic acids and other compounds 

 characteristic of contemporary protoplasm. Further, one may postulate the 

 emergence of some sort of primary systems, based on these substances, which 

 changed under the influence of the external medium and which could undergo 

 selection. The evolutionary development of these systems may be regarded as 

 the third stage which led, finally, to the emergence of the simplest primary 

 organisms. 



It is, of course, a very involved and extremely difiicult undertaking, not only 

 to give a theoretical explanation of the most important events which occurred in 

 the past, but also to obtain proof of the correctness of this explanation. 



We have, as yet, no single satisfactory account of the phenomena which 

 occurred at some time on our planet. We want to verify our assumptions, either 

 by observations of natural phenomena which are taking place at present, or by 

 experimental reproduction of the separate stages of the development of matter 

 which we have postulated. 



This sort of approach to the question opens up wide possibilities for practical 

 work by scientists on the problem of the origin of life. This work, however, does 

 not consist in hopeless attempts to produce the sudden spontaneous generation 

 of organisms (as was the case earlier), but in the study and experimental repro- 

 duction of phenomena which are not only quite possible, but which follow laws 

 and which arise successively during the evolutionary development of matter. 



It is quite obvious that an undertaking of this sort is not within the powers of 

 any single investigator, or narrowly specialized scientific team, for the develop- 

 ment of matter leading to the origin of life takes place by means of phenomena 

 which are studied by workers in different scientific fields and requires, for its 

 understanding, and even more for its reproduction, the mastery of many 

 different techniques of investigation. Furthermore, it is essential that the 

 investigations carried out should be made into a whole by the common acceptance 



