MAN, THE ANIMAL 9 



than a dozen fossil species are known to science 

 but not one of them is accepted as the ancestor of 

 our modern horse. All of these fossil species are 

 easily recognized as horses and we have iden- 

 tically the same kind of problem that was just 

 described for man. 



We need not take all of our illustrations from 

 extinct life, for the same principle is illustrated in 

 the numerous domesticated animals and plants. It 

 is probable that man started the present numerous 

 varieties of domestic fowls from the wild jungle 

 fowl of India. To-day by careful breeding experi- 

 ments, he has more than lOO distinct varieties but 

 all are unquestionably fowls. The same is true 

 of horses, sheep, wheat, oats, etc. Man may be 

 able to control the mating in such a way as to pro- 

 duce a given variety but not in such a way as to 

 produce or create a new genus. 



This seems to mean that the more than hun- 

 dreds of thousands of genera of animals and 

 plants known to science became fixed before man 

 thought of seriously questioning their origin. 

 The result is that the life of to-day is highly spe- 

 cialized and carefully adapted to a given kind of 

 environment. This gives us a non-plastic series 

 of forms to deal with, and science has thus far 

 been utterly unable to reconstruct the conditions 

 under which former changes must have taken place. 

 Some of us feel that such problems as these must 



