Epigenetics: Weak Model

“This is the new “Lamarckian” view that environmentally-induced changes in the DNA, often affecting the methylation of DNA bases, could be an important contributor to evolution. The problem with this is that these changes are not permanent, and are often effaced after one or two generations.

The record, I think, now stands at 31 generations before the environmentally-induced changes are wiped clean. But this provides no permanent basis for permanent adaptive change, which is the huge problem with the epigenetics “paradigm.” Further, when real adaptations can be genetically mapped in organisms, they always reside in the DNA sequence itself and not in the temporary alterations of DNA bases produced by the environment. Further, because environmentally induced epigenetic changes are temporary, they can’t participate in evolution by genetic drift, either.

Now there are adaptive epigenetic changes that are coded in the DNA itself: genes that code for instructions like, “Methylate bases at positions X, Y, and Z.” But those instructions evolved by conventional natural selection, and are not the types of epigenetic changes touted by promoters of the New Paradigm.

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