That's How It Happened

The "undetected adultery problem" vexes attempts to definitively establish very long lineages, aka descent from antiquity:

"Available documentation typically gives more information about paternity than maternity, and usually reflects the parentage that was accepted in an individual’s lifetime. However, modern research has shown that as many as 10% of the children born in some Western societies have a biological father who is not the officially documented father of the child. While the adultery rate surely fluctuated over time and by social class, it is a simple calculation to show that any very long patrilineal descent is unlikely to be biologically accurate, even if the historical accuracy of the documentation for each link is unimpeachable."

Kung Te-cheng holds the current genealogy crown, as being plausibly a 77th generation descendant of Confucius. Two related concepts: matrilineage and prosopography (which is nothing to do with prosopagnosia). (via)