On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life

A book by British naturalist Charles Darwin, first published on November 24, 1859, widely regarded as the foundation of evolutionary biology and natural philosophy. It presents Darwin’s theory of evolution through natural selection, based on observations of biodiversity collected during the HMS Beagle voyage (1831–1836), as well as statistical data and experiments. The author demonstrates that populations exhibit inheritable variations that, due to the struggle for existence, allow the most adapted organisms to survive and reproduce, leading to the gradual formation of new species and the branching tree of life. Darwin thoroughly explores the mechanisms of natural selection—from external traits and body form to behavior and disease resistance—providing examples such as domesticated pigeons and the Galápagos finches, which show adaptation to different environments. The book also elaborates on the concept of the struggle for life, where population growth leads to competition for limited resources, and introduces sexual selection, explaining the development of bright coloration and mating rituals in birds. Written in a popular scientific style, the book sparked widespread debates in scientific and religious communities, significantly influencing the development of modern biology and changing perspectives on the origin of life.