Descended from whom???

I know who my doctoral advisor was.  And of course, I know who his advisor was.  But for many years the chain had stopped there.  Then yesterday, my PhD student casually mentioned that I had some pretty famous people in my academic lineage: and sure enough, when I checked the mathematic genealogy database, the line had been filled in.  And yes, sure enough, there were some pretty stunning names in the list.

Yours, descended from Isaac.  Isaac Barrow.  Via Isaac Newton!
N.