454 Evolution and Adaptation 



author. While the only test of utility is the success of the 

 organism, even this does not indicate the utility of one part 

 of the economy, but rather the net fitness of the whole." 

 Keeping in mind the admonitions contained in the two pre- 

 ceding quotations, let us pass in review and attempt to ana- 

 lyze more fully the different points that have been considered 

 in the preceding chapters. 



It has been pointed out that the evidence in favor of the 

 theory of evolution appears to establish this theory with great 

 probability, although a closer examination shows that we are 

 almost completely in the dark as to how the process has 

 come about. For example, we have not yet been able to 

 determine whether the great groups of animals and plants 

 owe their resemblance to descent from a single original spe- 

 cies or from a large number of species. The former view is 

 more plausible, because on it we appear to be furnished with 

 a better explanation of resemblances as due to divergence 

 of character. Yet even here a closer scrutiny of the homol- 

 ogies of comparative anatomy shows that this explanation 

 may be more apparent than real. If discontinuous variation 

 represents the steps by which evolution has taken place, the 

 artificiality of the explanation is apparent, at least to a certain 

 degree. 



Admitting that the theory of evolution is the most prob- 

 able view that we have to account for the facts, we next 

 meet with two fujther questions, — the origin of species and 

 the meaning of adaptation. These are two separate and dis- 

 tinct questions, and n ot one __and the same as the Darwinian 

 theory_ claims. The fact that all organisms are more or 

 less adapted to live in some environment appears from our 

 examination to have no direct connection with the origin of 

 the adaptation, for, in the first place, it seems probable that, 

 in general, organisms do not respond adoptively to the envi- 

 ronment and produce new species in this way ; and, in the 

 second place, there is no evidence to show that variation 



