THE EPIC OF EVOLUTION 521 



Moreover, the struggle for existence is not necessarily a cruel, bloody, 

 hand-to-hand encounter. On the contrary it is unconscious in most 

 cases, and when death comes it is usually during the earlier stages of 

 life, painless and without worrisome premonition or warning. Na- 

 ture's ways are simply the way things are, wholesome and innocent, 

 and not tinged either with the bitterness of human hate or with 

 sweet sentimentality. It is wise to remember that most of the sup- 

 posed joys and sorrows of animals and plants are quite beyond 

 our ken. 



Survival and Elimination 



Left to herself, Nature either "mends or ends." The result of the 

 struggle for existence is, in most instances, the survival of the fittest, 

 that is, of those best adapted to cope with the circumstances to which 

 they are subjected. Stated another way, it is the elimination of the 

 unfit, namely, those that fail to make good. Both are processes that 

 tend to provide better ancestors for succeeding generations. 



It is not always the ''fittest" by any means that survive, for the 

 best do not invariably succeed in living. Sometimes it is the lucky 

 ones rather than the best. When a whalebone whale, for example, 

 strains out a million microscopic crustaceans from the sea-water 

 in taking one gigantic swallow of the animated sea-soup which 

 constitutes its food, those that escape are not necessarily the best 

 fitted to survive. 



The more we examine details, however, the fewer are the cases 

 in which there does not appear some factor of structure or be- 

 havior that plays a determining part in survival or elimination. 

 Sudden environmental changes usually result disastrously in the 

 extinction of organisms, while gradual changes tend to allow latent 

 adaptive possibilities in plastic plants and animals to come into 

 expression. 



Specialization is hazardous, because, although by means of it an 

 organism may become better fitted to one set of conditions, it results 

 in a loss of plasticity and of the organic resources necessary to meet 

 changes successfully. Better adaptation means having more re- 

 sources for survival. The great group of insects, for example, have 

 gained their dominance in the animal world, as demonstrated by their 

 great numbers and diversity, partly, without doubt, because of their 

 small size, short life-cycle, and infinite variety, all factors that have 

 aided them to survive. 



