AMERICAN NATURALIST 
Vout. XXVIII. March, 1894. 327 
THE ENERGY OF EVOLUTION. 
By E. D. Cope. 
1 PRELIMINARY. 
In considering the dynamics of organic evolution, it will be 
convenient to commence by considering the claims of Natural 
Selection to include the energy which underlies the process. - 
That Natural Selection cannot be the cause of the origin of new 
characters, or variation, was asserted by Darwin;' and this 
- opinion is supported by the following weighty considerations. 
(1) A selection cannot be the cause of those alternatives from 
which it selects. The alternatives must be presented before 
the selection can commence. 
(2) Since the number of variations possible to organisms is 
very great, the probability of the admirably adaptive structures 
_ which characterize the latter having arisen by chance is 
extremely small. 
(3) In order that a variation of structure shall survive, it is: 
necessary that it shall appear simultaneously in two individ- 
uals of opposite sex. But if the chance of its appearing in one 
individual is very small, the chance of its appearing in two 
individuals is very much smaller. But even this concurrence 
: of chances would not be sufficient to secure its survival, since 
It would be immediately bred out by the immensely prepon- 
: ` Origin of Species, Ed. 1872, p. 65. 
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