The Genes Don't Have the Last Word: Epigenetics Comes to Town

 From DNA to Epigenetics For many years, scientists thought that the discovery of the DNA double helix provided the solution to the code of life. Whatever the DNA code says, the organism does, they said. But the thought occurred to many that every cell has the same DNA in it and yet cells in different locations know that they should turn into part of a fingernail or part of a kneecap, and not part of the spinal chord. These considerations led to the conclusion that DNA is only an instruction book, waiting for decoding and implementation on request. But how does this work? A different set of biological systems is necessary to read and act on the instructions in the DNA library. And here we enter the realm of epigenetics. Epigenetics refers to the change in gene functions not relating to changes in the gene sequencing or changes in the gene itself. Dictonary.com defines it more clearly: Epigenetics is “the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself” (Dictionary.com). In other words, the very same unmutated gene could cause the beaks of some birds to grow shorter and thicker during one year and then the next year ca use the birds to grow longer and thinner beaks. (I ’d like to know if anyone has investigated the Galapagos finch beak changes with this in mind. Is the birds’ DNA actually changed by mutation and selection as the traditional story goes, or are the differen...
Source: The Virtual Salt - Category: Neurology Authors: Source Type: blogs