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To: allmendream

Does this ring a bell???

According to classical evolutionary theory, phenotypic variation originates from random mutations that are independent of selective pressure. However, recent findings suggest that organisms have evolved mechanisms to influence the timing or genomic location of heritable variability. Hypervariable contingency loci and epigenetic switches increase the variability of specific phenotypes; error-prone DNA replicases produce bursts of variability in times of stress. Interestingly, these mechanisms seem to tune the variability of a given phenotype to match the variability of the acting selective pressure. Although these observations do not undermine Darwin’s theory, they suggest that selection and variability are less independent than once thought.

http://linkinghub.elsevier.com/retrieve/pii/S0092867407001213


777 posted on 08/20/2008 3:05:14 PM PDT by GodGunsGuts
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To: GodGunsGuts
“Phenotipic variation originated from random mutations”. Check.

“Epigenetic switches increase the variability of specific phenotypes” (not genotypes). Check.

So how again can epigenetic switches change genotype? You still cannot provide an answer.

778 posted on 08/20/2008 3:10:19 PM PDT by allmendream (If "the New Yorker" makes a joke, and liberals don't get it, is it still funny?)
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