The Origin of Species · Chapter
Breeds of the Domestic Pigeon, Their Differences and Origin explained
Darwin examines the extraordinary diversity among domestic pigeon breeds, arguing that all descend from the wild rock-pigeon (Columba livia).
What happens
Darwin examines the extraordinary diversity among domestic pigeon breeds, arguing that all descend from the wild rock-pigeon (Columba livia). He details the anatomical, behavioral, and color variations across breeds like the carrier, tumbler, runt, barb, pouter, and fantail, and refutes the notion of multiple aboriginal stocks by showing the improbability of such extinction and the common reappearance of ancestral traits in crosses. He emphasizes the role of artificial selection by fanciers over millennia, noting that breeders often mistakenly believe each breed originates from a distinct wild species, a caution for naturalists studying species in nature.
Themes in this chapter
Domestication and Artificial Selection
Darwin uses pigeon breeds as a prime example of how artificial selection by humans over thousands of years produces dramatic variation, analogous to natural selection in the wild.
Variation and Inheritance
The chapter details extensive variation in skeletal, feather, and behavioral traits among pigeon breeds, and the inheritance of these traits across generations.
Common Descent and the Tree of Life
Darwin argues that all domestic pigeon breeds share a common ancestor, the rock-pigeon, despite their apparent differences, supporting the principle of common descent.
Characters to notice
- Charles Darwin
Author and narrator; presents his detailed study of domestic pigeons, their variations, and his argument for common descent from the rock-pigeon.
- Van Mons
Cited as an example of a cultivator who believes each fruit variety descends from a distinct species, illustrating the breeder's perspective.
- Mr. Youatt
Mentioned implicitly as a breeder or authority on cattle; referenced in the context of breeders' convictions about distinct origins.
- Bakewell
Referenced as a celebrated raiser of Hereford cattle, used as an example of a breeder who rejects common descent.
Key passages
“Great as are the differences between the breeds of the pigeon, I am fully convinced that the common opinion of naturalists is correct, namely, that all are descended from the rock-pigeon ( Columba livia ), including under this term several geographical races or sub-species, which differ from each other in the most trifling respects.”
Despite the vast differences among pigeon breeds, Darwin firmly agrees with naturalists that they all originate from the rock-pigeon, including its minor geographic variants.
Darwin states his core conclusion about the common ancestry of domestic pigeons.
“Hence the supposed extermination of so many species having similar habits with the rock-pigeon seems a very rash assumption.”
It is unreasonable to assume that many species with habits like the rock-pigeon have gone extinct, as the rock-pigeon itself persists even on small islands.
Darwin argues against the idea of multiple original wild stocks by noting the unlikelihood of their extinction.
“Ask, as I have asked, a celebrated raiser of Hereford cattle, whether his cattle might not have descended from Long-horns, or both from a common parent-stock, and he will laugh you to scorn.”
When Darwin asked a famous Hereford cattle breeder if his cattle could share ancestry with Long-horns, the breeder ridiculed the idea.
Darwin illustrates how breeders often reject common descent despite evidence, a caution for naturalists.