Epigenetics

In biology, and specifically genetics, epigenetics is mostly the study of heritable changes that are not caused by changes in the DNA sequence; to a lesser extent, epigenetics also describes the study of stable, long-term alterations in the transcriptional potential of a cell that are not necessarily heritable. Wikipedia

It is extremely interesting new field. Modern research into epigenetics has really only been going on since the early to mid 2000s. There is still so much to learn about it and the technology to do the research is advancing incredibly rapidly. As an example, the Human Genome Project took over 15 years and cost $3 billion to sequence the first human genome. As of January of this year, there are companies that will do DNA sequencing that can sequence and entire human genome in under a week and for less than $1000.