DOI link for Natural Selection
Natural Selection book
This chapter focuses on how the struggle for existence bears on Natural Selection. Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult-at least to have found it so-than constantly to bear this conclusion in mind. A plant which annually produces a thousand seeds, of which only one of an average comes to maturity, may be more truly said to struggle with the plants of the same and other kinds which already clothe the ground. A struggle for existence inevitably follows from the high rate at which all organic beings tend to increase. Climate plays an important part in determining the average number of a species, and periodical seasons of extreme cold or drought seem to be the most effective of all checks. Natural selection will modify the structure of the young in relation to the parent, and of the parent in relation to the young.