The Mathematics Genealogy Project is a website where you can trace the mathematical lineage of almost anyone from your own lecturers to Carl Friedrich Gauss.
So how do mathematical family trees work? Well, when someone gets a PhD, then they consider their supervisor to be their academic “parent” and it all branches out from there. Mind you, if you want to be included on the Mathematics Genealogy Project, then you probably have to fill in an application form yourself, since there are many people graduating in different areas of mathematics so it’s hard to keep track.
The cool thing about formalising this through the Mathematics Genealogy Project is that you can trace chains of supervision back many generations and find surprising connections.
For example, tracing back my lineage, I find that Poisson is my (great)7 grandfather, and going back a generation or two from that, you find Laplace, Lagrange and even Euler!
You can also see who you are “related to” – for example, I have 21 siblings (i.e., students with the same PhD supervisor as mine), 17 nieces and nephews, and 389 cousins.
Some analysis has also been done on the data of the Mathematics Genealogy Project considered as a graph. That is, we take everyone on the website to be a vertex, and join supervisor-student pairs.
Most recently, in 2016, Cosmin Ionita and Pat Quillen used Matlab to determine that out of 200,037 vertices in the graph, 180,094 (around 90%) lay in the largest connected component. In other words, 90% of mathematicians on the site are related in some way! Strangely enough, there’s also 7639 isolated vertices, which means we don’t know anything about those people’s advisor or any students they might have had.
There’s also a list of people who have had the most students out of anyone on the website. Topping the list is C.-C. Jay Kuo, a distinguished professor of electrical engineering and computer science at the University of Southern California, who has had 165 PhD students. That’s an average of over 5 students a year since his first student graduated in 1991!
So, have a play around with the Mathematics Genealogy project. You never know who you’re related to!