DARWIN'S DILEMMA* 



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DARWIN reared his theory of Natural Selection upon the 

 basis of three observable facts in the world of living 

 things, and two deductions which he made from these 

 observations. The first two observations are the following: 

 organisms tend to increase their numbers in a geometrical ratio 

 such that, if unchecked, the individuals of a given type of 

 organism would quickly become so great in number that no 

 country could support them. On the other hand, and this is 

 the second observation, the numbers of a given type of organism 

 do in fact remain relatively constant. 



The first deduction made from these first two observations 

 to account for them is what Darwin called " the struggle for 

 existence." For if nature produces more individuals than can 

 survive, the greater number of them must, for some reason or 

 other, be destroyed. Now this Darwin accounted for by com- 

 petition between organisms, resulting in survival of those that 

 are sufficiently equipped by their quality, or are favored by 

 circumstances, such as the seed that falls on fertile ground. 



Darwin's third observation was that organisms tend to vary. 

 His first example is that of variation under domestication, of 

 wheat, for instance, of pigeons, of horses, and of hounds. Now 

 this is attributed to man's power of selection. These variations 

 are intended by man. However deliberate the choice, not all of 

 these variations that are brought about are actually the result 

 of a deliberate selection — not all. Deliberate choice, improve- 

 ment of environment, or cross-breeding, are not all there is to 

 this selection. Darwin pointed out that, 



. . . eminent breeders try by methodical selection, with a distinct 

 object in view, to make a new strain or sub-breed, superior to any 

 kind in the country. But for our purposes, a form of Selection, 

 which may be called Unconscious, and which results from everyone 



* These pages are the transcript of a recording. 



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