Only 1% Paternal Discrepancy

From Paternity detective by Andrew Curry.  The subheading is Geneticist Maarten Larmuseau tackles a touchy question: How often are children genetically unrelated to their presumed fathers?

Doing a lot of genealogical work over the years, I have always kept in mind the concept of EPP, Extra Paternity Pairing, i.e. unknown cuckolding events.  If the rate of EPP is high, you have to anticipate ta high degree of low confidence four, five, and six and more generations back.  Nothing personal, just statistics.

For the longest time, the estimated rate of EPP in Europe (and North America), has been relatively high - from 5-20%.  The biological connection between present and past rapidly erodes with those high rates.  The historical and family cultural connection may be intact, just not the biological connection.

 But is it 5-20% EPP?  No one really knew.  

After an initial estimate published in 2013, Larmuseau kept collecting data. In a 2019 Current Biology article based on testing the Y chromosomes of 513 pairs of distantly related men, Larmuseau calculated that over the past 500 years, the EPP rate in Belgium and the Netherlands was about 1.5%. “To have some evidence for what the rate really was, and how that played out in those societies, is super interesting,” Jobling says.

Subsequent studies elsewhere in Europe by Larmuseau and others came up with essentially the same results: In European societies since at least the Middle Ages, the likelihood a child’s recorded father wasn’t the genetic father was vanishingly small—typically 1%, or less.

1% is, to me, astonishingly low, particularly in the context of 500 years of continental European history.  There are few locations which were not serially occupied by invading forces and/or civil collapse.  Environments where coerced sex, and therefore EPP, might be expected to happen with greater frequency.  

I accept the 1% estimate as viable, but retain an asterisked element of skepticism.  

But if 1% is correct, it implies a greater probability of a match between biological and documented paternity for much greater lengths of time, deeper into history.