I've never heard of the British study you propose being the source of my observation. But it doesn't matter. If we're talking about deep ancestry, like say t

I've never heard of the British study you propose being the source of my observation. But it doesn't matter. If we're talking about deep ancestry, like say tracing your lineage back to Charlemagne (which seems to be a popular anchor), you're talking about 40 to 50 "fathers" between the good old King and a modern descendent. If there is a 1% probability in each generation that the paternity recorded was wrong, then you're looking at at least a 1 in 3 chance that your paternity chain is broken. If the rate is even as high as 2%, it's 1 in 3 that the chain isn't broken. One break, of course, and your claim of descent is invalid.