8 BASIC ASSUMPTIONS 



and nucleoproteins will form by random combination. This 

 would mimic the conditions under which we believe life originated. 

 The second method is to use specialised chemical and physical 

 techniques to synthesise proteins and nucleoproteins, and having 

 synthesised them, then to place them in their correct structural 

 relationship. In this way, the combination of synthetic proteins, 

 nucleic acids, lipids and carbohydrates might lead to the forma- 

 tion of a simple virus-like compound that could reproduce in 

 living cells. The next stage would be the development of an 

 artificial solution to maintain the artificial virus. With these steps 

 accomplished we should have learnt a great deal about the processes 

 taking place in the living body and no doubt we should have dis- 

 covered new rules for physics and chemistry, but we could not 

 say from our experiments that the living material in the universe 

 arose in this way. The results would show that living matter can 

 arise by synthetic methods devised in the laboratory, but it 

 would still be possible that there were other methods by which life 

 actually arose in the universe. For a full discussion of the origin 

 of life one should consult the following articles: Oparin (1957); 

 Bernal (1954); Pringle (1954); Pirie (1954); Haldane (1954). 



Life arose only once 



The assumption that life arose only once and that therefore * 

 all living things are interrelated is a useful assumption in that it 

 provides a simple working basis for experimental procedure. But 

 because a concept is useful it does not mean that it is necessarily 

 correct. The experimental basis for this concept in particular is 

 not as definite and as conclusive as many modern texts would have 

 us believe. 



Biochemical evidence. Biochemists and comparative physi- 

 ologists usually assume that all protoplasm, no matter where it is 

 found, has the same fundamental biochemical and biophysical 

 processes taking place in it. But even an elementary study of the 

 situation shows that there are often many different ways of 

 carrying out a simple process in the animal kingdom. One well- 

 known example is that of carrying oxygen in solution; various 

 substances such as haemoglobin, haemocyanin, haemerythrin and 

 chlorocruorin are known to be capable of combining with oxygen. 

 But the common possession of a specific blood pigment does not 



