Notes on Ancestral Relationships Galton's notes, titled "On the greatest number of ancestral relationships of like degree, to a member of a population that has sprung from a single couple"; plus a clipping from The Gardeners' Chronicle containing a letter written by Galton, requesting advice on a proposed experiment "intended to be carried on by a process of "backward selection"... to learn the number of generations that must elapse before the original form is reached, under specified conditions of culture and selection." 1895