CHAPTER VII 



Progressive and regressive variations Recapitulation Reappearance of the 

 characters of remote ancestors Regression in domesticated animals Crosses 

 between natural races Gallon's theory of heredity The bulk of characters 

 inherited from remote ancestors The village-sheik Prehistoric human 

 remains Conclusions. 



HITHERTO we have considered only those variations which 

 are additions to the already existing characters in living 

 organisms. These are known as " progressive " variations. 

 As variations occur in all directions, it is evident that only 

 a few of them can be of use to the organism, while a large 

 number of them must be either disadvantageous or useless. 

 It is easy to understand that disadvantageous variations will 

 be eliminated by natural selection, as the organism in which 

 they occur will have no chance of surviving in the struggle 

 for existence against the more fortunate individuals which 

 possess advantageous variations. All variations which are 

 additions to the stock of characters are progressive, and some 

 of them, although not disadvantageous, are not advantageous. 

 Though these indifferent variations are not harmful to the 

 organism, according to the evidence which we have con- 

 sidered up to the present there is no apparent reason why 

 they should not be preserved in the offspring as well as the 

 advantageous characters. Moreover, it is also evident that 

 characters at one time advantageous to a race may cease to 

 be so if the environment changes, and may become either 

 indifferent or actually disadvantageous. We have seen that 

 characters no longer useful tend to disappear. This disap- 

 pearance of characters also depends upon variations, but 

 these variations are " regressive " and not " progressive." 

 Thus we have two kinds of variation, " progressive " and 



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