← All chapters

The Origin of Species · Chapter

I: Variation Under Domestication explained

Darwin introduces the concept of variation under domestication, arguing that domestic organisms vary more than wild ones due to changed conditions of life.

What happens

Darwin introduces the concept of variation under domestication, arguing that domestic organisms vary more than wild ones due to changed conditions of life. He discusses causes of variability, the roles of definite and indefinite variation, and the importance of selection by man in shaping domestic breeds. He also addresses the difficulty of distinguishing varieties from species and the origin of domestic races from one or more wild stocks.

Free preview opens on this chapter — companions, themes, and character notes appear beside the text.

Narrative arc

Story tension across the book — this chapter sits in Exposition.

SetupEscalationAftermathClimax
  • Setup
  • Escalation
  • Breaking point
  • Aftermath
  • Closing

This passage marks the story's dramatic climax because Darwin shifts from a defensive posture against objectio…

Full beat labels and climax notes unlock in the reader.

Follow the arc while reading

Themes in this chapter

Characters to notice

  • Charles Darwin

    Author and narrator, presenting his observations and conclusions on variation under domestication.

  • Professor Weismann

    Cited for his insistence on the two factors of variation: the nature of the organism and the nature of the conditions.

  • Kölreuter

    Mentioned in the context of the reproductive system's sensitivity to changed conditions and variability.

  • Mr. Youatt

    Referenced for his emphasis on selection as the means of improving domestic breeds.

Key passages

  • “When we compare the individuals of the same variety or sub-variety of our older cultivated plants and animals, one of the first points which strikes us is, that they generally differ more from each other than do the individuals of any one species or variety in a state of nature.”

    Domesticated plants and animals show greater individual variation than their wild counterparts.

    Darwin's opening observation on variability under domestication.

  • “Man can hardly select, or only with much difficulty, any deviation of structure excepting such as is externally visible; and indeed he rarely cares for what is internal.”

    Human selection focuses on external traits, not internal anatomy.

    Explains why domestic breeds often differ greatly in external features but less in internal organs.

The Origin of Species — I: Variation Under Domestication Explained