The Evolution of Improved Fitness 5. Conclusion Clearly what we observe in the antibody response is evolution in miniature. In this model we can learn the structure of each antibody gene at the beginning of the experiment before the challenge with antigen, and observe the accumulation of randomly induced mutations under natural selection for progressively improved function. This model of evolution is similar to the computer simulation discussed earlier, but it has three advantages as a persuasive example. First, it is a natural biological phenomenon rather than a theoretical designed simulation. Second, the initial unmutated sequence is selected for its ability to bind the antigen molecule, so it clearly has some function (which must be "undesigned," since the antigen may be a novel synthetic chemical never found in nature). In contrast, critics of Dawkins's weasel model argue that it is unreasonable to assume that the initial random sequence chosen by the computer could have any function at all. Third and finally, as in real phylogenetic evolution, the selection pressure is for
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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.