The Origin of Species · Chapter
Character of Domestic Varieties; Difficulty of Distinguishing Between Varieties and Species; Origin of Domestic Varieties from One or More Species explained
Darwin examines the nature of domestic varieties, noting that they often show less uniformity and more extreme variation in certain parts compared to true species.
What happens
Darwin examines the nature of domestic varieties, noting that they often show less uniformity and more extreme variation in certain parts compared to true species. He discusses the difficulty of distinguishing between varieties and species, the debate over single versus multiple origins of domestic breeds, and argues that many domestic races have arisen from a single wild stock through inherited variation and selection, though some, like dogs, likely descend from multiple wild species.
Themes in this chapter
Domestication and Artificial Selection
The chapter focuses on domestic varieties, their origins, and the role of human selection in shaping breeds.
Variation and Inheritance
Darwin discusses the variability of domestic races and the inheritance of traits across generations.
Characters to notice
- Charles Darwin
Author and narrator; presents his observations and conclusions on domestic varieties.
- Mr. Blyth
Provided facts on the habits, voice, constitution, and structure of humped Indian cattle.
- Professor Rütimeyer
His admirable researches are cited as establishing the specific distinction between humped and common cattle.
- Oswald Heer
Remarked on the advanced civilisation of lake-inhabitants of Switzerland.
- Sir John Lubbock
Sir J. Sebright experimented with crossing to obtain intermediate races and failed.
Key passages
“Domestic races often have a somewhat monstrous character; by which I mean, that, although differing from each other and from other species of the same genus, in several trifling respects, they often differ in an extreme degree in some one part.”
Domestic breeds frequently exhibit exaggerated features in one particular aspect, even though they differ only slightly in other ways from each other and from related wild species.
Darwin highlights the tendency of domestic varieties to show extreme variation in specific traits.
“I cannot doubt that if other animals and plants, equal in number to our domesticated productions, and belonging to equally diverse classes and countries, were taken from a state of nature, and could be made to breed for an equal number of generations under domestication, they would on an average vary as largely as the parent species of our existing domesticated productions have varied.”
Darwin argues that if a comparable set of wild species were domesticated and bred for many generations, they would likely show as much variation as current domestic species.
This supports his view that variation under domestication is a general phenomenon, not limited to a few special species.
“The offspring from the first cross between two pure breeds is tolerably and sometimes (as I have found with pigeons) quite uniform in character, and everything seems simple enough; but when these mongrels are crossed one with another for several generations, hardly two of them are alike, and then the difficulty of the task becomes manifest.”
First-generation hybrids between pure breeds are often uniform, but subsequent interbreeding of those hybrids produces great diversity, making it very difficult to create a stable intermediate breed.
Darwin illustrates the complexity of producing new breeds through crossing.