Charles Darwin is the famous English scientist. After the round-the-world travel by the Beagle ship, on the basis of the material collected by it he created the theory of evolution which excites minds of scientists still.
Charles Darwin allocated several finds which roused him to creation of the theory. First, it is the hardened remains of the ancient mammals covered with an armor as if modern battleships. Secondly, Darwin noticed that in process of his advance across South America the sibling species of animals replaced each other. And, thirdly, he found out that on various islands of the Galápagos archipelago the closely related types differ from each other a little. These facts haunted the scientist, and on arrival he was accepted to considering of the evolution of types.
About the origin of species thanks to natural selection Charles Darwin worked on the idea within twenty years. As a result the scientist publishes the book which immediately finds both passionate adherents, and severe criticism.
The essence of the Darvinian theory can be stated in brief in several postulates. According to the scientist's conclusions, within each look there is an inherited variation of various signs – morphological, physiological, behavioural. This variation can be shown, or not be shown, but it is always. All living organisms breed in a geometrical progression. However natural resources are limited therefore there is a fight for survival, both between individuals of one look, and between the types occupying one ecological niche. In the conditions of the most severe competition survive and the most adapted animals give posterity only. Signs which helped parents to survive are descended to posterity. And, these useful signs can result also from mutations, and then to be transferred to descendants. And natural selection of one look living in different conditions leads to maintaining various useful signs in these two populations, and, therefore, to formation of new types.