What is being - had not published his work, out of fear of...

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What is being 'selected' by natural selection? The environment has chosen your species, who by chance are best adapted to environmental conditions are the most reproductively successful- that is, the produce the most offspring who survive- and so pass on their adaptive traits to more offspring. What is doing the natural selecting? The environments that the organisms are living in. Who was Alfred Russel Wallace? He travelled and collected plant samples in the Amazon basin in association with Henry Walter Bates (1842-52) and was similarly employed the Malay Archipelago and the Spice Islands (1854-62). Wallace theorised on the basis of his findings and was influenced in this theorising by Thomas Malthus' Essay on Population. The outcome of Wallace's ruminations was that he went on to propound a theory of the evolutionary origin of species by natural selection. He sent his findings to Darwin who had already postulated the same idea, he just
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Unformatted text preview: had not published his work, out of fear of retribution. Can you explain Darwin's three postulates: there is a struggle for existence; there are variations in fitness within all species; and traits are heritable? 1. There is a struggle for existence - Scientists before Darwin thought that competition or "struggle for life" might be the reason for the survival or extinction of species. Darwin felt that such a struggle might also occur between the members of a species, determining which individuals survived and reproduced and which did not. 2. There are variations in fitness within all species - Some species are better adapted for certain environments. Fitness (the ability to adapt) helps determine what species will continue or go extinct 3. Traits are heritable - certain traits can be passed to other members of the same species he just didn't understand how this worked because he had not heard of Mendel's work at the time....
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