The Origin of Species · Chapter
Unconscious Selection explained
Darwin explores the concept of unconscious selection, where humans gradually improve domestic breeds without intending to create permanent changes, through the repeated breeding of the best individuals.
What happens
Darwin explores the concept of unconscious selection, where humans gradually improve domestic breeds without intending to create permanent changes, through the repeated breeding of the best individuals. He illustrates this with examples from dogs, cattle, pigeons, and plants, showing how slow, insensible changes accumulate over centuries, often without historical record. He contrasts this with methodical selection and notes that even in barbarous societies, unconscious selection occurs through the preservation of useful animals. Darwin also discusses how this process explains the adaptation of domestic races to human needs and the difficulty of identifying wild parent-stocks of long-cultivated plants.
Themes in this chapter
Domestication and Artificial Selection
Central theme: unconscious selection as a form of artificial selection that gradually modifies domestic breeds without deliberate intent to create new varieties.
Natural Selection and the Struggle for Existence
Mentioned as a process that may also act on domestic animals in uncivilised regions, leading to the formation of sub-breeds.
Variation and Inheritance
Underpins the mechanism of selection: slight variations appear and are inherited, allowing gradual accumulation of change over generations.
Characters to notice
- Charles Darwin
Author and narrator, presenting the concept of unconscious selection and its role in domestic breeding.
- Mr. Youatt
Cited for an illustration of unconscious selection in Leicester sheep, showing how two flocks from the same original stock diverged into distinct strains.
- Bakewell
Mentioned as a breeder who methodically modified cattle forms and qualities, and whose original stock was used by Buckley and Burgess.
- Sir Charles Lyell
Referenced indirectly through the context of geological and biological change, though not explicitly named in this excerpt.
- Dr. Hooker
Not directly mentioned in this chapter excerpt; included as a placeholder for potential future check-ins.
Key passages
“Thus, a man who intends keeping pointers naturally tries to get as good dogs as he can, and afterwards breeds from his own best dogs, but he has no wish or expectation of permanently altering the breed.”
A person who wants to keep pointers will naturally seek the best dogs and breed from them, without any intention or expectation of permanently changing the breed.
Illustrates unconscious selection: improvement occurs without conscious goal of creating a new breed.
“Slow and insensible changes of this kind could never be recognised unless actual measurements or careful drawings of the breeds in question have been made long ago, which may serve for comparison.”
Such gradual and imperceptible changes can only be detected if precise measurements or drawings were made in the past for comparison.
Highlights the difficulty of documenting unconscious selection due to its slow pace.
“If there exist savages so barbarous as never to think of the inherited character of the offspring of their domestic animals, yet any one animal particularly useful to them, for any special purpose, would be carefully preserved during famines and other accidents, to which savages are so liable, and such choice animals would thus generally leave more offspring than the inferior ones; so that in this case there would be a kind of unconscious selection going on.”
Even among the most barbarous peoples who do not consider heredity, a useful animal would be saved during famines and thus leave more offspring, resulting in a form of unconscious selection.
Extends unconscious selection to all human societies, regardless of their level of civilisation.
“No one would ever expect to get a first-rate heartsease or dahlia from the seed of a wild plant.”
Nobody would anticipate obtaining a high-quality heartsease or dahlia by sowing seeds from a wild plant.
Demonstrates the cumulative effect of selection in improving cultivated plants beyond their wild ancestors.
“But to use such an expression as trying to make a fantail is, I have no doubt, in most cases, utterly incorrect.”
I am convinced that saying someone 'tried to make a fantail' is usually completely wrong.
Emphasizes that breeders did not aim for extreme traits; these arose gradually through selection of slight variations.
