Frog, so we have gone from 25% (plus or minus one eighth) to 12.5%. Well, we are getting there. Now the PR referred to "low levels of admixture (such as that which may have been contributed by a single great grandparent)." Now what this means is that the test can detect admixture resulting from the ancestry (a number between 0-100% for the ancestry concerned) contributed by the ancestor in question. That is not the same thing at all as what you are inferring (as I suspect you know very well). Now either you do not understand this or you are being deliberately obtuse (dare I use the phrase "wilfully misunderstanding").