A book published in November 1859
John Murray published Darwin’s On the Origin of Species in London on November 24, 1859. Darwin assembled observations of plants and animals, breeding practices and geographical distributions to explain change and divergence through natural selection.
The book began with variation under domestication. Pigeons, livestock and cultivated plants had inherited differences on which breeders could act, offering familiar examples from which to approach variation in nature.
How differences accumulate through reproduction
Organisms often produce more offspring than can survive and reproduce, while individuals within a population differ. In a particular environment, some inherited differences help their bearers leave more descendants. Over many generations those traits can become more common.
Darwin called this process natural selection. Environment, competition and reproduction connected individual differences with long-term adaptation and divergence.
Common ancestry and branching descent
The branching diagram in the book portrayed lineages diverging through time. Descendants of one ancestor could develop in different directions; some branches expanded while others became extinct. Similarities and differences among species became evidence of related descent.
Fossils, island distributions, embryos and shared anatomical structures supplied further material, approaching biological relationships through time, geography and form.
Discussion and subsequent research
On publication day Darwin wrote to Huxley, thanking him for his response. The book and their correspondence carried the argument into wider scientific discussion, as naturalists reconsidered observations of species, variation and relatedness.
Genetics later explained the transmission of traits, and population studies measured how inherited differences change. Questions raised by the book entered experimental and statistical work on inheritance, reproductive success and the formation of lineages.