I'm no expert on the drift and the size of barriers you might need, but again it seems to me that it comes back to what tolerance there is. If you say you're organic and you have zero tolerance, it puts a huge cost on somebody, so again you've got to come up with a reasonable tolerance. What is the honest health risk of having a very small presence from genetic drift? I think that's the honest question.
On February 7th, 2011. See this statement in context.