NURTURE VERSUS NATURE 



crease of population is largely promoted by the 

 less desirable, rather than by the more desirable, 

 members of the community. 



Whereas all evolutionary progress in the past 

 has been due, we are led to believe, largely to 

 natural selection of the fittest members of the 

 animal and vegetable populations as the propa- 

 gators of the species, mankind is now making 

 the experiment of artificial selection, in which 

 the survival of the unfit becomes the outstanding 

 feature. 



It is as if Mr. Burbank were to select among 

 cross-bred plants the ones that showed the least 

 desirable qualities, and were carefully to preserve 

 the seed of these, destroying the seed of the more 

 desirable members of the colony. It needs no 

 profound knowledge of plant breeding to predict 

 what must come to pass were this plan to be fol- 

 lowed in the orchard or field or garden. No one 

 will for a moment suppose that Mr. Burbank 

 could have produced his remarkable new varieties 

 of plants by such a method. No one doubts that 

 the application of such a method would result in 

 the rapid retrogression of even the best varieties, 

 so that they would presently be represented by a 

 degenerate progeny. 



It is equally little in doubt that a breeder of 

 thoroughbred horses, or of special varieties of 

 dogs or chickens or pigeons, would work havoc in 

 the ranks of his pedigreed stock were he to en- 

 courage the breeding of inferior members and re- 

 strict the breeding of superior ones. 



[311] 



