Cook : Eugenics and Breeding 



31 



Eugenic reform is not likely to attain 

 very wide popularity if it is expected to 

 result in a condition in which all the 

 children of a family are to be as much 

 alike as twins. Yet this is the ideal of 

 the breeder, and the end that is attained 

 by the application of the breeders' 

 methods of improvement. Hence we 

 ma}^ expect that a more adequate study 

 of the problems of eugenics will lead to 

 the development of methods altogether 

 different from those that are in use 

 among breeders of plants and animals. 

 Progress must be made in eugenics 

 without destroying or even seriously 

 diminishing the normal individual diver- 

 sity, that feature of human heredity 

 with which we are most familiar. 



A clear understanding of the nature, 

 conditions, and causes of organic evo- 

 lution is even more important for the 

 eugenist than for the breeder. With 

 the condition of individual diversity 

 retained, the eugenic progress of man- 

 kind will have much more analogy with 

 the normal evolutionary progress of 

 wild species of plants and animals than 

 with the breeding of uniform domesti- 

 cated varieties. Too many writers on 

 eugenics overlook the need of a broader 

 and more truly biological point of view, 

 and restrict their attention to the facts 

 of heredity that have been learned from 

 garden or laboratory experiments with 

 domesticated forms. 



The select strains that breeders 

 develop from single superior individuals 

 do not represent permanent steps in 

 the evolution of the species, and often 

 endure for only a few generations. New 

 varieties are brought forward continu- 

 ally to take the places of those that drop 

 out. Thus from the standpoint of the 

 species, the breeder may be said to 

 destroy the best individuals when he 

 uses them as the parents of short-lived 

 varieties. We are now beginning to 

 appreciate the importance of preserving 

 the wild, unselected types of our domes- 

 ticated plants and animals, to serve as 

 storehouses from which vigorous new 

 varieties may be drawn as needed in 

 the future. 



ELIMINATION NOT ENOUGH. 



In the conscious improvement of 

 mankind the permanent interests of 



whole nations or races have to be con- 

 sidered instead of the formation of 

 specialized short-lived varieties. It will 

 not be sufficient to eliminate the con- 

 spicuously defective individuals as a 

 plant breeder rogues out the "off" 

 plants in attempting to preserve a 

 variety from degeneration. Guarding 

 the fertility of the best is a much more 

 important issue than destroying or steri- 

 lizing the defectives. Galton's master- 

 mind perceived this clearly enough, but 

 many of his avowed followers have been 

 impressed too much by the analogies of 

 breeding. 



If the objects and methods of eugenics 

 are to be different, what have students 

 of eugenics to learn from the breeding of 

 plants and animals? The answer is 

 that the same natural laws or rela- 

 tions seem to be manifested in the 

 development of mankind as in the 

 heredity and evolution of the lowest 

 orders of plant and animal life. It is 

 through the study of breeding that 

 nearly all of our more definite know- 

 ledge of heredity has been gained in the 

 past and that increase of such know- 

 ledge may be expected in the future. 

 As far as eugenics is to be considered as 

 a branch of biological science, it can 

 not afford to neglect any facts or sug- 

 gestions that may be developed in any 

 other part of the biological field. 



The time may come perhaps, when 

 eugenics can be studied as a separate 

 branch of heredity, without reference to 

 the breeding of plants and animals, but 

 for the present, and for many years in 

 the future, the plants and animals must 

 afford our best opportunities for gaining 

 new experimental knowledge of hered- 

 ity. It would be as far from the truth 

 to suppose that the plants and animals 

 can be neglected by eugenics as to sup- 

 pose that the plant and animal methods 

 can be applied directly to mankind. 



The recently awakened interest in 

 eugenics means that the future progress 

 of himianity is to be aided by a conscious 

 recognition of heredity as another 

 chapter of the laws of nature that we 

 must learn to obey. Thus far we have 

 been content to float unconsciously, as 

 it were, down the stream of life, feeling 

 no creative responsibility for the future 



