39. Surname Extinction and Genealogy

There was concern among many English Victorians in the mid-1800s that aristocratic surnames were becoming extinct.  Heaven forbid!  Francis Galton, a British polymath originally posed a mathematical question circa 1873.  The Reverend Henry William Watson replied with a solution. Together, they prescribed the process named the Galton-Watson Process of how surnames might disappear over time.  

 

You do not have to be a mathematician to readily see from the chart the decreasing survival rate of a surname as the number of generations increases. The process models family names as patrilineal (passed from father to son), while offspring are randomly either male or female, and names become extinct if the family name line dies out (i.e., holders of the family name die without male descendants). The formula is of limited usefulness in understanding actual family name distributions, since in practice family names change for many other reasons and dying out of name line is only one factor.  People sometimes choose to change their surnames.  People are adopted into new families, inheriting a new surname.  Sometimes folks change their surname just because they do not like the original.  

 

To learn more, join your local genealogical society to learn more about surnames and their survival (or not).

 

For the mathematicians in the crowd, Galton and Watson used a stochastic process to model their work and Poisson Distribution to generate the random numbers.  Still, their solution was not complete and required an American mathematician to complete the proof in 1950. 

 

Ron Gilmore

Email:            rvg3@me.com

Website:        https://www.rgenealogy.ca