SciGuy, We are definitely splitting hairs now. Allow me a nit and an attempt to sum up. The nit; Get on with what? It’s not that simple. It depends on the strength of the association. I believe I inferred the strength of the association when I said it was 'causal'. The summation; Ancestry is a very imprecise attempt to locate a genetic variance in a bio-geographical subgroup when it cannot be located by other mean. regards, frog