The theory of evolution by natural selection states the "fittest" animals or plants are more likely to survive and reproduce.

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Wallace, who was born in Monmouthshire and also lived in Neath, was the co-discoverer of the theory of evolution by natural selection.

BBC: Alfred Russel Wallace's 19th Century letters go online

Thousands of Wallace's letters have been put online for the first time, including correspondence with Darwin about evolution by natural selection.

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Scientist Alfred Russel Wallace, who proposed the theory of evolution by natural selection with Charles Darwin, corresponded with the great and good of 19th Century society.

BBC: Search for Alfred Russel Wallace's 19th Century letters

Letters written by scientist Alfred Russel Wallace, who proposed the theory of evolution by natural selection with Charles Darwin, will be published online for the first time.

BBC: Alfred Russel Wallace's 19th Century letters go online

These included well known naturalists such as Alfred Russel Wallace, who collected specimens in the Amazon and Malay Archipelago and independently formulated a theory of evolution by natural selection.

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In the same way that evolution by natural selection can produce purposeful designs without an intelligent designer to prefigure the purpose, so animals can show behavior that evolved to be purposeful but is not psychologically motivated.

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Darwin said evolution occurred by natural selection where the "fittest" animals or plants were more likely to survive and reproduce.

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