EVOLUTION AND THERMODYNAMICS 



were not a number of different elements from which they could be 

 formed. The world of life is a painting in full colours, not a mono- 

 chrome. If this is accepted, we must make a sharp distinction between 

 thermodynamic order or separatedness, and biological organisation 

 or patterned mixed-up-ness. And the general upshot would be that 

 the world has been moving steadily from a condition of universal 

 separatedness (order) to one of general chaotic mixed-up-ness 

 (thermodynamic disorder) plus local organisation (patterned mixed- 

 up-ness). 



The point could perhaps be illustrated by a homely analogy. 

 Inside the nursery cupboard there are certain large boxes of bricks, 

 each box containing bricks of identical colour and shape. When they 

 are all tumbled out in confusion on the nursery floor we have the 

 highly probable universe of the thermodynamician. But when in one 

 comer of the room the bricks are assembled into a factory or a railway 

 station, we have an analogy for the organising activities of life. 

 There are two kinds of mixed-up-ness, indistinguishable for the 

 physicist, but clearly visible to the biologist who is on the look-out 

 for patterns. 



The only thinker who seems to have arrived at somewhere ap- 

 proaching this position is the late J. S. Haldane.^ He clearly expressed 

 the idea that though with the passage of time thermodynamic mixed- 

 up-ness constantly increases, this mixture does not necessarily give 

 rise to chaotic states but on the contrary invokes much pattern and 

 organisation. Indeed, we may find the first traces of pattern even in 

 those "fortuitous concourses" of particles which gases and homo- 

 geneous liquids were formerly thought to be, for it is now thought 

 that temporary associations of particles exist in these systems, though 

 they are of a duration so transient that they can only be observed 

 by special methods. Such organisation would be around the mole- 

 cular level. 



Thermodynamic order and Biological organisation essentially different. 



We have arrived, then, at the conclusion that thermodynamic order 

 and biological organisation are two quite different things. But this 

 is not to say that there are no connections between them. What 

 Haldane said illustrates some of the connections. And there is another 

 very simple way of showing how pattern may arise where there was 



^ See especially J. S. Haldane, Realist, 1930, 3, lo, and The Philosophy of a Biologisty 

 (Oxford, 1936), p. 25. 



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