We can't know how significant epigenetics is until scientists define it.
NEW YORK CITY, NY—Back in December, the geneticist Mary Claire King warned that, when it comes to epigenetics, "we have a semantic problem that's becoming a philosophical problem—and on the verge of becoming a dangerous political one." She meant that scientists themselves were being a bit sloppy with defining epigenetics, the process by which long-term biological changes can occur without changes in the underlying DNA. This sloppiness is now leading to public confusion about what exactly is involved in epigenetics and how it might affect human health and behavior. In the absence of clear ideas, non-scientists are grasping at any meaning they find convenient and using that to draw grand conclusions about human nature.
Unfortunately, nearly every aspect of this confusion was on display at a panel called "The Social Impact of Epigenetics," part of this past weekend's World Science Festival in New York. The panel started with grand declarations about how Lamarck might have been on to something about the inheritance of acquired characteristics. But before it was over, one panelist was saying that we only have a single clear example of this in mammals, and it involves coat color in mice.
For the rest of the story: http://arstechnica.com/science/2013/06/is-our-genome-a-straight-jacket-or-a-comfy-sweater/