CHAPTER XVIT 

 NATURAL SELECTION 



CHARLES DARWIN 



Introdttctory Note. — This entire chapter is made up of carefully chosen 

 oassages from Darwin's Origin of Species. So much has falsely been called 

 " Darwinism " that it is well for the reader to have a statement of Darwin's views 

 in his own words. Every student of evolution should read the whole of the Origin 

 of Species. It is all so good that one finds it difficult to leav^e out anything. The 

 following excerpts will, we believe, give the gist of natural selection. 



We present first certain of the ideas that underlie or are postulates of the 

 theory; then the theory itself is presented; the theory of sexual selection inter- 

 polated; and then follow examples of the way in which adaptations are accounted 

 for by natural selection. Darwin's own statement of the most serious difficulties 

 and objections to the theory, and his answers to these, bring this chapter to a close. 



FOUNDATION STONES OF NATURAL SELECTION 

 DARWIN's own estimate as to the RdLE OF NATURAL SELECTION IN EVOLUTION 



No one ought to feel surprised at much remaining as yet unex- 

 plained in regard to the origin of species and varieties, if he make due 

 allowance for our profound ignorance in regard to the mutual relations 

 of the many beings which Hve around us. Who can explain why one 

 species ranges widely and is very numerous, and why another allied 

 species has a narrow range and is rare ? Yet these relations are of the 

 highest importance, for they determine the present welfare and, as I 

 ueheve, the future success and modification of every inhabitant of this 

 »vorld. Still less do we know of the mutual relations of the innumer- 

 able inhabitants of the world during the many past geological epochs 

 in its history. Although much remains obscure, and will long remain 

 obscure, I can entertain no doubt, after the most deliberate study 

 and dispassionate judgment of which I am capable, that the view 

 which most naturahsts until recently entertained, and which I for- 

 merly entertained — namely, that each species has been independently 

 created — is erroneous. I am fully convinced that species are not 

 immutable; but that those belonging to what are called the same 

 genera are lineal descendants of some other and generally extinct 

 species, in the same manner as the acknowledged varieties of any one 

 species are the descendants of that species. Furthermore, I am con- 

 vinced that Natural Selection has been the most important, but not 

 the exclusive, means of modification. 



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