DAK WIN, r.KFOUK AND AFTKK 1(^19 



Natural Selection was tlie process suj^^osted by Darwin 

 to account for tlie origin of new species, by the preserva- 

 tion or survival of tlie fittest variations. 



Charles Darwin attached nmch importance to two 

 factors, naniely, the existence of small, fluctuating varia- 

 tions, — referred to i)reviously, and the occurrence of a 

 struggle for existence between organisms, owing to the 

 natural increase in numbers and the resulting ])ossible 

 lessening of the food supply. The possessors of the fitter 

 variations tended to survive. If this was kept up con- 

 sistently, then by new ada])tations, and ])robably with the 

 lielp of some form of isolation, new species arose. Tlie 

 strength of the hypothesis of Natural Selection lies in 

 its interpretative value. Darwin's hypothesis, supported 

 by Alfred Russel Wallace ( 1 823-1 91o), was championed 

 by Huxley (1825-1895) and by Haeckel (1834-1919). 

 Haeckel laid much stress on the recapitulation 

 hypothesis, or biogenetic law as he termed it. Un- 

 fortunately, the terms evolution and natural selection 

 have been confused under the term Darwinism. Evolution, 

 as has already been stated, is a mode of organic progress, 

 while natural selection is (mly a hypothesis, providing 

 a reasonable suggestion as to how evolution may come 

 about. The phrase " Struggle for existence ■' was used 

 by Darwin in a metaphorical sense, for in the first edi- 

 tion of his ^^ Origin of Species" he wrote: ''I should 

 premise that I use the term " struggle for existence " in 

 a large and metaphorical sense, including the dependence 

 of one being on another." 



Darwin towards the end of his life was much more 

 favourably disposed towards the opinions of Lamarck 

 than he had been earlier. Thus, in the sixth edition of 

 his '' Origin of Species," regarding modification of species, 

 he wrote :^' This has been effected chiefly through the 

 natural selection of numerous, successive, slight, favour- 

 able variations; aided in an important manner by the 

 inherited effects of the use and disuse of parts; and in 



