Wednesday, June 10, 2020

Untangling the Spaghetti Bowl

Do you ever have a small project to tackle which, despite its size, is so messy, you put off handling it? That's how I feel about taking on the recently-added family tree building option at DNA company 23andMe.

While 23andMe apparently first unveiled their automated tree-building technology in beta form back in October, 2019, I didn't notice the option until it was released from test mode earlier this year. At first, I was excited to see its arrival—as were many others who wanted to see a tree built solely from input from DNA inferences. Upon closer inspection, however, my enthusiasm began to cool. The chart looked as organized as a diagram of a bowl of spaghetti strands.

My first hint that this automated attempt might not be as science-y and high tech as hoped for came when I took a peek at my husband's tree at 23andMe. Right away, I could see his 23andMe customer cousins were listed a generation off from their true relationship. Of course, that's what being the baby of the baby can do for generational alignment, but it wasn't immediately apparent how I could correct the error, other than answer a questionnaire and provide feedback.

Thankfully, the feedback was immediately taken and adjustments easily made. But that was on my husband's tree. When I looked at mine, with its messy history of a paternal grandfather who buried his true origin once he arrived in his adopted homeland, I could see there were paternal matches showing on both sides of my tree.

Keep in mind there really is no way, currently, to tell solely from one DNA test which side of a family a match belongs to. It is possible to determine whether a test taker is genetically male or female, but when it comes to isolating which chromosome patterns come from mom or from dad, we really need to have a known match to help us triangulate. A machine-generated tree is not capable of sorting things to that fine a degree.

And so, we help the automated by rearranging the nodes on the tangled lines in the relationship chart. Those undulating wavy lines, as they are represented in the 23andMe version of a pedigree chart, can be edited, augmented, and rearranged. The way to do so, however, became apparent only gradually.

I found my first clue that this was possible not from its source—23andMe as originator of the service—but thanks to a genetic genealogy blogger. It was Kitty Cooper's blog post at the end of May which first alerted me to the fact that the 23andMe blog had anything to say about it.

Thankfully, they have—and I've read it over very carefully. The task is still going to be a messy process—hence my hesitation to just jump in and get to work—but it's a try-as-you-go experiment, anyhow.

My first step was to take 23andMe up on their option to wipe everything clean and start afresh. Despite the warnings that any self-made edits would be lost in the revision, I had nothing to lose—and hopefully a chance for an updated run at the data.

Now comes the long slog: adding in the names I know of my direct lines, sorting the maternal from the paternal, and getting the right spaghetti strand attached to the right ancestor's line of descent. I go nearly cross-eyed trying to keep all those curvy lines straight.

On the bright side: perhaps, at the end, I'll have found a way to correctly attach my mystery cousins from Wisconsin into my paternal grandfather's tree. I'm already to the point where I can spot which ones are the mystery ones; it's just a matter of plugging them into the right branch of the tree.

After all, if I don't like the placement, 23andMe has devised a way for us to move entire branches of the tree from one node to another. They're flexible like that.


  1. Wow sounds like you will be busy! :)

    1. In a seems like busy work, in another way. Sometimes, I just wish it was as easy as uploading a GEDCOM file.

  2. I haven't gone beyond my great-grandparents in the 23andMe tree yet. There was such a mess of "spaghetti" like you said. And my paternal side had some double cousins that have complicated things. Lots of wrong generations showing up too.

    1. I think the "wrong generation" issue will soon straighten itself out. All it took, in one instance on my husband's test, was to give 23andMe some feedback, and it was corrected within a day. The double cousin situation will also throw them for a loop, as will any endogamy issues. But if you have already aligned your spaghetti bowl tree at 23andMe all the way to your greats, you certainly have fortitude, Sara!


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