Perhaps you read The New Yorker article by Siddhartha Mukherjee on epigenetics last week. Or maybe you skipped straight-ahead to the critiques, in which scientists and journalists holler that the story ignores key research areas, and dances around details to the point of being misleading.
One thing that everyone seems to agree upon: gene regulation is complicated. As is writing about it for a non-specialist audience.
At Scientific American, we've tackled the challenge of illustrating different aspects of epigenetics a few times over the last five years. In the spirit of helping to establish baseline understanding of the topic, here are a few figures from the archive.
I'd be remiss if I didn't point out that—like The New Yorker article—the graphics presented here do not attempt to present all epigenetic mechanisms and do not include the transcription factors that are so critical to gene activity. These illustrations were originally produced to accompany articles on specific lines of research by Eric Nestler (2011) and Michael Skinner (2014), respectively. But I think they are useful, in providing some context: Specifically, what are epigenetic modifications, and how might they play out across generations?