370 SESSION IV. DISCUSSION 



parativc anatomy there has been a tendency towards the functional morphology and bio- 

 chemistry of developing organisms. 



As a next stage in the development of the study of the origin of life it would be valuable 

 to set up an organization co-ordinating the specialities mentioned; until now each has 

 been studied separately. It has already been shown that there is a close connection between 

 cosmogony, astronomy, geology and synthetic, analytical and biological chemistry, a 

 fact which has been clearly expressed in the Reports of our Symposium, but this group 

 of studies must be extended to include some of the biological sciences which do not yet 

 form part of it. 



It would be valuable to use the 15th Zoological Congress to effect this association. I 

 have requested the organizing committee of this Symposium that enough copies of the 

 EngUsh texts of the Reports to the Symposium might be made available for them to be 

 distributed to the delegations of the various countries at the Zoological Congress in 

 honour of Darwin. 



Finally, I should like to say a few words about an aspect of the problem of the origin 

 of life which has not yet been directly touched on in this Symposium ; it does, however, 

 force itself upon one. Is there life anywhere else in the Universe ? We naturally judge life 

 by the way it manifests itself on the Earth. Life is the mode of existence of protein bodies. 

 These, however, can only exist under narrowly limited conditions of the external, abio- 

 logical medium. These latter are determined by the whole preceding history of the 

 formation of our solar system. Supposing the temperature conditions were raised to 

 20-30"C above the present optimum, then life, as we know it today, would be impossible. 



I would remind you of that excellent book by Alfred Rüssel Wallace — Man's Place in 

 the Universe (1903). It was translated into the Russian language during the first World 

 War. In discussing all the conditions necessary for life as it now exists, Wallace Unks them 

 with the formation of the Earth as a planet in our solar system. He arrives at the perfectly 

 well-founded conclusion that life could only have arisen outside the Earth if there had 

 been an exact repetition of all the spatial, temporal and qualitative conditions of the 

 evolution of the Earth in the solar system. It is hard to imagine that these could really have 

 been reproduced 'letter for letter' anywhere in the Universe, for all the abundance of its 

 stellar systems. 



A few comments should, however, be added to this perfectly justifiable conclusion. In 

 speaking of Ufe somewhere outside the Earth, one thinks of those forms of Ufe which exist 

 on the Earth. There is, however, nothing improbable in the idea that, in some planets 

 in the Universe, organic material may have arisen. If we substitute the concept of 'being' 

 for that of life, there is nothing improbable in the idea of the possibility of the 'being' of 

 such organic material even outside the Earth. On this hypothesis it would be pointless to 

 try to assign to it those qualities which we know as the characteristic features of life on 

 the Earth, still less those of the 'Martians' described by the lively imaginations of writers. 



N. W. PIRIE (Gt. Britain): 



I do not think that a discussion of the intimate details of the habits of tobacco mosaic 

 virus (TMV) has any strict bearing on the origins of life. Furthermore I do not think 

 that it is useful to speak of nucleic acids conveying the information needed for specifying 

 a protein. They do not start protein synthesis in an empty structureless system but they 

 may move into a host cell that was already making proteins and alter the specifications to which 

 they are made. The differences may be trivial ones that concern only one or two amino- 

 acids or one fold. 



However, because the question of TMV has been raised, I would like to ask a question 

 that may clarify a point about the infective preparations that can be made from it and 

 that contain nucleic acid. Dr Schramm is perfectly correct in saying that the molecular 

 weight of a long thin particle cannot be measured with an ultracentrifuge. But the length 

 of a TMV particle can be measured with an electron microscope. If therefore all the 

 particles of TMV in Dr Fraenkel-Conrat's TMV preparations were much shorter than 

 is normal for TMV but gave a nucleic acid preparation of normal infectivity, then it is 

 clear that there has either been reaggregation or else TMV fragments shorter than the 



