Quote Originally Posted by glenlivet View Post
...2) you're assuming that biological paternity is always recorded accurately...

Probably in most cases it is, but what if you run across an illegitimacy?

Your ability to 'prove' a blood connection is more tenuous that you might wish to recognize.

....

I don't think this matters for genealogical (as opposed to genetic or medical)purposes. The coming of genetic genealogy has altered the way we think of paternity and families. Historically, approximately 3.7-4% of births in the US and most of Europe are cases of misattributed paternity, or about one in 25. In genetic genealogy these are called non-paternal events, or NPE's. While one in 25 isn't much, the numbers accumulate over the generations. In fact there is a formula for determining the likelihood of an NPE in any given number of generations. If someone is interested, I can dig it up. The probability goes from less that 50% to over 50% at 19 or 20 generations. In other words, using the span of 25 to 31 years per generation, in any lineage over 475 to 620 years old, or older than, say, 1388 to 1533 C.E. or so, it is more likely than not that an NPE has occurred.

In other words, those of us who used to so proudly brag of our descents from Charlemagne or the Magna Carta Sureties may not be so sure. (Of course, almost all of us of European ancestry are probably descended from Charlemagne, though perhaps not in the way(s) that we thought. But that is another story.)

So this calls into question what is paternity? What is family? If a man raises a son as his own, thinking it is, does that make him any less a son? If a person thinks of the man who raised him as his biological father, does that make him any less his father? I think not, for purposes of genealogy. Or for purposes of the affectional ties that bound them to each other.

Or for purposes of membership in a clan. According to Moncriefe of That Ilk and other authorities, illegitimacy is no bar to inheriting the chiefship of a clan. Why should the requirements for mere membership be more strenuous?