Epigenetic 'Dials'

Imagine that ‘test pattern’ on that antiquated TV screen represents a pattern encoded on a specific gene, say the pattern for blue eyes, since that represents my eye color. There are dials, and switches on the TV, however, that allow you to alter the ‘test pattern’ for blue eyes. By adjusting the dials and switches, you can alter color, hue, and contrast while not changing the original pattern for ‘blue eyes.’ [Look at your eyes through a magnifying glass. What do you see? I see a gray-blue color with little flecks of green and gold. This means that my eyes take on a slightly different hue depending on the color of clothing I am wearing.] To use this metaphor, studies of epigenetic dials have shown that they can create 2,000 plus variations from the same gene blueprint. Consequently, there are many blue eyes on this planet, each set likely having a slightly different pattern and hue—because each person’s external and internal environments differ slightly, just like their fingerprint.