Is there a decent taxonomy of wine varietals?

[DrHow]

It seems to me that, with DNA profiling, it should be possible to determine with some reasonable precision how various strains of grapes are related to one another. Yet my attempts to find any such attempt at classifying family relations between types of grapes has turned up nothing useful. I was hoping to find what might be a family tree for grape types. Which are genetically descended from what? Because of crosses, it need not be a strict tree.

If one exists, can someone point me to such a resource?

(If I had such a thing, I could answer curiousity questions such as, "Is it just coincidence that some Tempranillo wines remind me of Zinfandel?")