Charles Darwin's "The Origin of Species" has shaped scientific thought since its publication in 1859. It outlines Darwin's theory of evolution by natural selection and supports his claim that humans all share a common ancestor.

Charles Darwin

Charles Darwin was a 19th century scientist who theorized that every creature on earth is descended from a common ancestor.

Origin of Species

Darwin's book "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life" (1859) outlined his theory of evolution and became his most famous work.

Theory

The theory of natural selection is "survival of the fittest." This means members of a species most suited to survive will live and reproduce, while the weaker animals of the species will gradually be killed off.

Ramifications

As the weak die off and the strong reproduce, superior traits are passed on until an animal can, over time, change form. For instance, what was once a fish is now a frog. This explains how it is possible for all the varied creatures on earth--including humans--to have descended from the same ancestor.

Example

Darwin spent time with pigeon breeders and found that they carefully selected pigeons with desirable traits to breed pigeons that had, for instance, ruffled necks. Darwin wrote that this selection process happens naturally in every species.

Source:

Allaboutscience.org: How does Darwin's theory of natural selection explain the origin of species?

Evolution.berkeley.edu: Natural Selection: Charles Darwin & Alfred Russel Wallace

Darwin-online.org.uk: Charles Darwin: gentleman naturalist; John van Wyhe