ThruLines are automatically added to DNA tests that meet the criteria described at the end of this post.
AncestryDNA’s ThruLinesTM are the third of three great additions to the genealogy arsenal to be announced at RootsTech 2019; the others are MyTreeTags and improved DNA Matches. ThruLines take the best aspects of DNA Circles and combine them into a tidy descendant structure that suggests the paths, or ThruLines, between you and your DNA matches. Unlike DNA Circles, it even works if you have a private tree, as long as it’s searchable.
Your main ThruLines page will show each of your ancestors in order: father, mother, father’s father, father’s mother, etc. If the system is able to find a potential ancestor who is not already in your tree, they’ll have a dashed box around them and a “Potential Ancestor” tag:
Here’s a set of ThruLines to my great grandfather, Sidney Hébert Sr. This was a big family (14 kids), and I can scroll to the left to see more descendant lines that have tested.
My path to Sidney Sr. is shown through my mom and grandfather. My second cousin on the far right has a path through his father then to Jimmy Hébert, my grandfather’s brother. Three descendants of Nelson have also tested; I could expand Nelson’s line with a click to see them as well.
As before, the boxes with dashed lines around them indicate people who are not yet in the tree and whom I might want to add. As with any automated hint system, there will be cases where the suggestion is wrong, so you should always check the records before adding people to your tree based on ThruLines.
Also unlike DNA Circles, you and your match needn’t have both trees built back to the common ancestor. AncestryDNA’s computers can reconstruct a hypothetical path by stitching together information from different trees. Consider this ThruLine:
The lineage from me back to Donasien Domingues is taken from my tree. The one from cousin SS, however, is pieced together from a couple of different trees, first Sarah’s, then Alanna’s. Of course every such hint needs to be independently validated, but these computer generated hints can save hours of time tracing potential connections.
Shared DNA and Probabilities
Each ThruLines match is labeled with their user name, their tree-based relationship to you, and the amount of DNA they share. If you click on the DNA amount, you’ll get a treat.
A pop-up shows you how likely each possible relationship is given how much DNA is shared. These types of statistics underlie the What Are the Odds tool (WATO) and a great way to assess whether the relationships in the ThruLines are reasonable.
What’s especially interesting is that the probabilities in ThruLines are not exactly the same as the ones used by WATO. Until AncestryDNA publishes a White Paper explaining their numbers, I’ll be collecting crowd-sourced data to better understand their numbers. You can contribute percentages from your own ThruLines here: https://goo.gl/forms/VliO4OHWDdwKBP3p1
On the main ThruLines page showing all of the ancestors, it would be very helpful if the number of matches in each ThruLine was indicated. As is, you can click on a ThruLine only to find that there’s nothing new there.
Also, I’d like to be able to zoom out of a ThruLines page to see all of the connections at once, ideally in a print-friendly format.
How to Get ThruLines
ThruLines will be made available on 27 February, 2019, to any Ancestry member who (1) has AncestryDNA results linked to a public tree or a private searchable one, (2) has DNA matches also linked to a tree, and (3) has a tree that extends back at least 3–4 generations. While the tool is in the beta testing phase, ThruLines are free, although I anticipate they’ll only be available to subscribers in the long term.