How Darwinism Stands To-Day :;<;; 



Proposition II. If the individuals that have varied profit- 

 ably get the reward of their superiority, and if the individuals 

 that have varied unprofitably, or not at all, are handicapped by 

 their inferiority, this will have an effect on the character of the 

 stock, or race, or species, provided that the novel peculiarities are 

 hereditarily entailed on successive generations. If the individuals 

 with profitable peculiarities (let us say, plus variants) are con- 

 sistently favoured, and if their virtues are consistently handed 

 on, their type will come to be that of the race. Whereas those with 

 unprofitable peculiarities or none at all (let us say, minus vari- 

 ants) will be weeded out and will gradually disappear. Professor 

 R. C. Punnett has calculated that, "If a population contains .001 

 per cent, of a new variety, and if that variety has even a 5 per 

 cent, selection advantage over the original form, the latter will 

 almost completely disappear in less than a hundred generations." 



Proposition III. But there cannot be sifting or selection 

 without a sieve, and that is to be found in the struggle for exist- 

 ence. Living creatures are hemmed in by limitations and con- 

 fronted by ever-changing difficulties. There is a tendency to 

 over-population; circumstances are changeful; the vigorous crea- 

 ture is a hustler. There is struggle for food, for foothold, for 

 self-preservation, for mates and for family well-being indeed, 

 for luxuries as well as for necessaries. There is struggle between 

 fellows of the same kind, for a hungry locust may devour its 

 neighbour and even the Amoeba may be a cannibal. There is a 

 struggle between foes of quite different kinds, between the graz- 

 ing herd and the marauding carnivores, between the kestrel hawk 

 and the nimble field-voles. There is struggle also between living 

 creatures and their inanimate surroundings, the struggle against 

 cold and heat, against wind and wave, against drought and flood. 

 Subtle beyond description and almost ceaseless in its operation is 

 nature's sifting, which Darwin called Natural Selection. In 

 domestication and cultivation it is Man who fosters and elimi- 

 nates; in nature the same kind of transformation as the breeder 



