The Genetic Pachinko for You and Me

In looking for other famous family trees, I came across someone who had compiled a tree for Winston Churchill with more than 6000 people in it. He graciously sent me a GEDCOM file of this tree, and I have included it as one of the samples in the (d3) family tree visualization project I am playing with. A screenshot is below. I had to cull people born before about 1300 because of (apparent) needed optimizations in the processing steps. It's kind of a mosh pit prior to 1300, anyway - the "widest point of the Ancestor Cone happens for most of us around 1200AD" (info via Tim Urban's awesome article on ancestors/pedigree collapse).

Visualization of Winston Churchill's Family Tree
GEDCOM file courtesy T. Dowling.
Interactive Visualization available at

(Better) Handling of Pedigree Collapse in a D3 Family Tree Visualization

I have been playing with building a d3.js family tree visualization (available at, where you can load your own GEDCOM family tree file, or explore prepackaged sample trees for some famous folks. The other day I realized that I was not really handling pedigree collapse properly under the hood. Visually, things worked, but the calculations related to "duplicate" people in the tree were not right. I needed to more properly keep track of the individual paths between nodes in order to tabulate duplicate folks. In doing this, it also made it easy to dynamically highlight the paths between a person in the tree and the "root" person when the user hovers on a person in the tree. A screenshot of the updated visualization is below (for the poor pedigree collapse "champion" Charles II of Spain).

The Family Braid for Charles II of Spain,
highlighting the different ways Charles V was related to him.
Charles V was his great-great-great-great grandfather,
his great-great-great grandfather (twice),
and his great-great grandfather
(direct link to this tree in the visualization)

Extreme Inbred Royalty - Charles II of Spain

Pedigree collapse in our own family tree is inevitable.

Charles II of Spain (1661-1700) was a product of it to an impressive degree.

I had seen a variety of trees showing this, but wanted to incorporate his tree into the "chronologically" family tree visualizer I've been playing with. I couldn't find a GEDCOM file that included much of his tree, so I just created a tree on (using this wiki page as a reference) and exported it as a GEDCOM file.

A screenshot of his tree is below (including a link to the interactive tree if you want to view more details on it).

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