Epigenetics upends natural selection and genetic mutation as the sole engines of evolution. Darwinian evolution is based on the genetic code of an individual being changed by mutation, causing the genome passed to the offspring to differ from that of the parent. But some morphological changes have taken place so radically and so pervasively that they cannot be explained by modern evolutionary theory. A far simpler explanation for this phenomenon is epigenetics, which can create radical physical and physiological changes in subsequent generations by the simple addition of a single small molecule and without genetic mutation. One commonly studied alteration is the addition of very short chains of carbon, oxygen, and hydrogen to particular nucleotides in DNA, typically silencing gene activity--somewhat as if someone canceled your delivery of bricks while you were in the process of building a house. Heritable epigenetics takes place when methyl molecules change the functioning of bo
