The Yule tree graph The Yule tree is a graph with one edge coming in and two edges coming out of each branch-point. The branches represent the time periods between the evolution of new species. If the ...

The Yule tree graph The Yule tree is a graph with one edge coming in and two edges coming out of each branch-point. The branches represent the time periods between the evolution of new species.

When a Yule tree is not a yule tree: in 1924, G. U. Yule created a graph to map genealogical history. At this time of year, the words “Yule tree” may conjure images of brightly decorated balsam firs.

Using data compiled from language resource ethnologue.com, Sundberg initially drew the language tree graph for the benefit of her comic book readers, and included fictional historical references.