Evolution and Chanc3

Evolution and Chanc3 - Evolution and Chance Bipartite...

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Evolution and Chance Bipartite Evolution Darwin called his principle of the evolutionary process "natural selection", a term that has given rise to almost as much confusion as the malignant phrase donated to him by the philosopher Herbert Spencer, "survival of the fittest". It has been understood to mean that the natural world is an agent, selecting according to some purpose or goal; that nature aims to perfect or complete the potential of a species. Nothing could be further from the truth. Natural selection in modern science is a feedback process. It requires two "forces", as it were, one acting to faithfully (but not quite perfectly) replicate the structure of the organism (reproduction and ontogeny) and the other sorting the interactive characteristics of organisms with the environment (the phenotype or set of traits) into those more or less efficient at survival and therefore at reproduction opportunities. A better term for it, therefore, is "environmental sorting of heredity", since it is the way in which certain traits equip organisms that increases or decreases their chances at being passed on, relative to other traits in that population of organisms. Sober [1984:99] illustrates the process in this way: imagine a child's toy that has numbers of three different size balls in a container, with two internal layers that have increasingly smaller holes in them. Shaking the toy (a randomising process) increases the likelihood that the smaller balls will pass through the first filter, and that the smallest balls through the second. The smallest balls are, in effect, the most "fit" (or make the best fit) and make it through to the bottom. There has been a selection, or sorting, process which results in the smallest balls making it to the bottom. The feedback loop in evolution results when the genetic structure
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This note was uploaded on 11/14/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

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Evolution and Chanc3 - Evolution and Chance Bipartite...

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