The Origin of Species · Chapter
Natural Selection; or the Survival of the Fittest explained
Darwin introduces the concept of natural selection as the primary mechanism driving evolution.
What happens
Darwin introduces the concept of natural selection as the primary mechanism driving evolution. He argues that the struggle for existence, combined with heritable variation, leads to the preservation of favorable variations and the elimination of injurious ones. He defends the term 'natural selection' against criticisms, explains how it leads to divergence of character and extinction, and uses the analogy of a tree to illustrate the branching pattern of life's history.
Themes in this chapter
Natural Selection and the Struggle for Existence
Central theme of the chapter; Darwin defines natural selection as the preservation of favorable variations and the destruction of injurious ones in the struggle for life.
Variation and Inheritance
Darwin emphasizes the importance of slight individual differences and the hereditary tendency as the raw material for natural selection.
Extinction and the Succession of Forms
Darwin explains how natural selection leads to extinction of less improved and intermediate forms, and the succession of modified descendants.
Characters to notice
- Charles Darwin
Author and primary narrator; introduces and defends the concept of natural selection.
- Dr. Hooker
Cited alongside Asa Gray for the remark that man does not directly produce variability but only preserves and accumulates it.
- Asa Gray
Cited alongside Hooker for the same remark on variability under domestication.
Key passages
“This preservation of favourable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest.”
Darwin defines natural selection as the process by which beneficial variations are preserved and harmful ones are eliminated, also termed 'survival of the fittest'.
Key definition of the chapter's central concept.
“The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth.”
Darwin uses the analogy of a branching tree to describe the relationships among all living and extinct species, with twigs representing existing species and branches representing extinct lineages.
Famous tree of life analogy illustrating common descent and divergence.