El origen de las especies –titulo original en ingles: On the Origin of Species– es un libro de Charles Darwin publicado el 24 de noviembre de 1859, considerado uno de los trabajos precursores de la literatura cientifica y el fundamento de la teoria de la biologia evolutiva.
El titulo completo de la primera edicion fue On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life –El origen de las especies por medio de la seleccion natural, o la preservacion de las razas favorecidas en la lucha por la vida–.
En su sexta edicion de 1872, el titulo fue cambiado a uno mas corto The Origin of Species –El origen de las especies–. El libro de Darwin introdujo la teoria cientifica de que las poblaciones evolucionan durante el transcurso de las generaciones mediante un proceso conocido como seleccion natural.
Presento pruebas de que la diversidad de la vida surgio de la descendencia comun a traves de un patron ramificado de evolucion. Darwin incluyo las pruebas que reunio en su expedicion en el viaje del Beagle en la decada de 1830 y sus descubrimientos posteriores mediante la investigacion, la correspondencia y la experimentacion.

On December 27, 1831, the young naturalist Charles Darwin left Plymouth Harbor aboard the HMS Beagle. For the next five years, he conducted research on plants and animals from around the globe, amassing a body of evidence that would culminate in one of the greatest discoveries in the history of mankind-the theory of evolution.
Darwin presented his stunning insights in a landmark book that forever altered the way human beings view themselves and the world they live in. In The Origin of Species, Darwin convincingly demonstrates the fact of evolution: that existing animals and plants cannot have appeared separately but must have slowly transformed from ancestral creatures. Most important, the book fully explains the mechanism that effects such a transformation: natural selection, the idea that made evolution scientifically intelligible for the first time.
One of the few revolutionary works of science that is readily accessible to the nonscientist, The Origin of Species not only launched the science of modern biology but has also influenced virtually all subsequent literary, philosophical, and religious thinking.

The Origin of Species sold out on the first day of its publication in 1859. It is the major book of the nineteenth century and one of the most readable and accessible of the great revolutionary works of the scientific imagination. Though, in fact, little read, most people know what it says—at least they think they do.

The Origin of Species was the first mature and persuasive work to explain how species change through the process of natural selection. Upon its publication, the book began to transform attitudes about society and religion and was soon used to justify the philosophies of communists, socialists, capitalists, and even Germany’s National Socialists. But the most quoted response came from Thomas Henry Huxley, Darwin’s friend and also a renowned naturalist, who exclaimed, “How extremely stupid not to have thought of that!”

Charles Darwin was just twenty-two when he went on his first voyage around the world in 1831. Darwin’s father at first refused to allow his young son to go on the voyage. Fortunately, his father relented, and Darwin’s journal is now considered by many to be the greatest scientific travel narrative ever written.
Revised by the author in 1860, this is an account of his experiences on the HMS Beagle, a ship that was mapping the coast of South America. What was set to be a two- or three-year voyage stretched out to a five-year adventure. Darwin took copious notes during the voyage, notes that would later lead to his formulation of the theory of evolution. He was able to observe coral reefs, fossil-filled rocks, earthquakes, and more, firsthand, and then make his own deductions.