Darwin defined it as "preservation of favorable variations and the rejection of injurious variations"
This preservation of favorable variations and the rejection of injurious variations, 
..... Dobzhansky defined species as that stage in the evolutionary process at... [DOC] [TLE] A Fundamentally New Perspective on the Origin and Evolution of ... [PAR] In the original words by Darwin, natural selection is defined as preservation of 
favorable variations and the rejection of injurious variations (1).