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Charles Darwin

The Theory of Evolution

Charles Darwin was a British scientist that developed his theory of evolution by natural selection based on changes he observed in such creatures as the peppered moth.

EvolutionEvolution is change over time. This theory can refer to any type of change, but this theory of evolution deals specifically with changes in living things.

Natural Selection Natural Selection the process whereby organisms better adapted to their environment tend to survive and produce more offspring.

The theory of biological evolution explains the changes that have occurred in living things during the history of life on Earth. It is a very important concept in modern biology and is based on the idea that all organisms are changed forms of living things that came before.

We see the effects of evolution in the diversity of plants and animals around us.

1859 Darwin published his theory of evolution by natural selection in a book entitled

On the Origin of the Species.In this book he noted that

organism with characteristics that were favorable for survival lived and passed these traits on to their off spring.

Those organisms that had traits that were not beneficial to survival often died prior to reproducing.

Natural Selection based upon

1. Organisms tend to produce more offspring than will survive.

2. Organisms must struggle to survive because resources, like food and shelter, are limited.

3. Individuals of a population different from each other. (much of this variation is inherited from parents. Some is due to mutation)

4. Those individuals that are best adapted to their environment will survive.

5. Those individuals that survive and reproduce best will leave more offspring than other individuals.

Galapagos IslandsDarwin developed most of his ideas about natural selection while on

a five-year voyage along the South American coastline. He served as naturalist on the ship called the Beagle.

While traveling, Darwin noted how different the South American Plants and animals were from the European plants and animals. He also noted the similarities between organisms. An especially interesting case was found on the Galapagos Islands, 965 kilometers off the west coast of South America. There, Darwin noticed that many species of birds from different islands closely resembled birds on other islands. Yet the birds from each tiny island also were distinctly different from the birds on the other islands. Each of the bird species had a slightly different beak shape that allowed it to use a different food source. It seemed as though each species was uniquely adapted to its particular environment. Darwin was so fascinated by the beak variations in finches that he began to study adaptations in many other animals. His study of unity and diversity in the animal kingdom allowed him to develop his theory of evolution by natural selection

ActivityGalapagos Finches:Galapagos Finches:

Famous BeaksFamous Beaks

http://www.hhmi.org/biointeractive/sorting-finch-species

http://www.sciencechannel.com/games-and-interactives/charles-darwin-game/