BIOLOGICAL DEATH AND REPRODUCTION 



have on a low entropy collection of material. Unless 

 means become available to repair the damage, the cell 

 will eventually be somatically mutated to the point 

 where it can no longer function. When this happens 

 the cell may be said to suffer natural death. 



The number of molecules in any one cell mutated, 

 as well as the number of particularly damaging muta- 

 tions is, other factors being equal, a function of time. 

 The age of a cell may then be said to correspond 

 roughly to the amount of mutated material it contains 

 which, at least statistically speaking, is a function of 

 the time during which its unbroken lineage has existed. 

 In this manner a fundamental relationship can be 

 established between the passing of time and such 

 physico-chemical processes in living material capable 

 of affecting biological structure. 



The simpler the structure of a cell, the smaller the 

 degree of molecular specialization — the less damaging 

 is the effect of any one mutation. The smaller its phys- 

 ical size, the lower is the probability of any one muta- 

 tion occurring during a given length of time. As a 

 result of all this, we find that simple cells can reproduce 

 indefinitely by means of only a binary-fission process, 

 (mitosis) as there will always exist cells which have 

 escaped mutation prior to fission and some of whose 

 offspring will likewise escape unharmed before their 

 own division and so forth. Of course some material will 

 be mutated in such a fashion as will result in eventual 



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