6 PROBLEMS OF EVOLUTION 



sea ? Of all mammals, why is the bat the only one truly 

 indigenous in New Zealand ? 



Of these arguments Nos. (l) and (2) are the most convinc- 

 ing. On a theory of separate creations the preliminary em- 

 bryonic stages of man, during which he belongs to various 

 other classes of animals in succession, are superfluous and 

 unaccountable. The evidence of Palaeontology compels us to 

 conclude either that there were numbers of separate creations 

 at different periods (mammals, for instance, being introduced 

 when the earth was peopled with lower forms), or else that 

 evolution has taken place. But embryology forbids us to accept 

 the alternative of separate creations, so that evolution remains as 

 the only possible explanation of the facts. 



Argu- Artificial selection in the course of many centuries has pro- 

 m c j uce( j verv divergent breeds of horses, cattle, dogs, pigeons, etc. 

 Darwin's It is true that all the efforts of breeders have not raised from 

 theory w j] ( j h orses anything but horses, from the wild rock-pigeons 

 anything but pigeons. But they have experimented only on 

 species in which specialisation had already gone very far, and in 

 which, consequently, the range of variation was narrow, 1 so that 

 we should rather wonder at the greatness of their success than at 

 their comparative failure. Moreover the time available has been 

 short. Palaeolithic man, as far as is known, had no domestic 

 animals. Most of those we have now were domesticated in the 

 neolithic period, probably less than a million years ago. And 

 during the greater part of this time there was, of course, a great 

 want of thoroughness and system about the breeders' methods. 

 Within this century many new breeds have been developed and 

 we cannot but wonder at the great triumphs of the short period 

 during which science and system have been brought to bear. 

 Nature, the great experimenter, took in hand at the outset un- 

 specialised and, therefore, more plastic forms and has continued 

 her experiments for millions of years. It is often maintained 

 that man has not produced results in any way similar to those we 

 attribute to Natural Selection since all his new breeds of pigeons, 

 for instance, are fertile inter se and are, therefore, mere varieties, 

 1 See PP- 137-H7- 



