It's a diagram mapping the genetic closeness of wine grapes, created by Cornell genetic researcher Sean Myles. Myles mapped the genetic makeup of 583 varietals and found that 75% of them are "close cousins who don't have a lot of sex." In other worse, our grapes are as inbred as 18th century royal families. Well, we do call them "noble."
This has some real implications for grape production - namely, that lack of genetic variation could make it easy for disease and pests to do their dirty work. But what I'm most interested in is the way the grapes relate to one another. Seeing the close proximity between Pinot Noir and Chardonnay is just as interesting as seeing how far those grapes are from Cab and Merlot. I think of Cab and Chardonnay as opposite sides of the same coin, but after looking at this diagram, I realize that's probably because of the way the two grapes are treated by winemakers, not because of the grapes themselves.
Also, check out Traminer. Who knew it was at the center of so much activity?!