The Interesting Case of the ThruLines

[Heatherblether]

Is it only trees or is it also dna matching segments? I only ask as 1001 trees have added a sister with husband and children (same name but born in a different parish etc etc) to my 3xgr grandfather - whilst I dna match to 2 descendants of other siblings, why nothing to the wrong trees . I know there are dna matches to each other ( we saw that during a glitch) and I certainly do not want them on my thulines - I am interested in the trees theory. Must be something else in the algorithm??

 

[Bob Spiers]

Is it only trees or is it also dna matching segments? I only ask as 1001 trees have added a sister with husband and children (same name but born in a different parish etc etc) to my 3xgr grandfather - whilst I dna match to 2 descendants of other siblings, why nothing to the wrong trees . I know there are dna matches to each other ( we saw that during a glitch) and I certainly do not want them on my thulines - I am interested in the trees theory. Must be something else in the algorithm??

It may be me, and likely is, but I do not understand the point(s) you are making, other than (perhaps) the question... are Thrulines based solely on 'other' Trees or on DNA or perhaps both? The answer to that is Thrulines are based on other 'Tree Comparisons'. Period!

Which leads to the conclusion (and pretty well known to serious researchers) that because there are some 'Mickey Mouse' Trees on Ancestry, some Thruline matching will be spurious, and others all shades between. The algorithm does what it is tasked to do and cannot by definition judge between the 'good, bad and ugly'. Perhaps it should and perhaps later it will, but for now it is what it is. In the meantime you have to be Judge and Jury on what is being offered, or you can - as I know others do - just disregard them.

If that misses the point of your posting, Sorry. Others will I am sure read more into your posting and respond accordingly.

 

[peter]

The answer to that is Thrulines are based on other 'Tree Comparisons'. Period!

That's true, but the aim of ThruLines is to hypothesise how you might be connected to your DNA cousins. So there should be someone at or near the top who is a DNA match.

 

[PhilGee]

... So there should be someone at or near the top who is a DNA match.

Thrulines, surely, always connects two DNA matches? Each person in the path between could, theoretically, come from a different tree (yes, I have had three consecutive people shown as from different trees) - my experience is that portions of three/four trees is not unusual.

The one thing I do not yet understand is why Thrulines gives me a connection via one "common ancestor" (so a half cousin), but uses my tree for all of my side and half of the other side of the link .

 

[peter]

Thrulines, surely, always connects two DNA matches? Each person in the path between could, theoretically, come from a different tree (yes, I have had three consecutive people shown as from different trees) - my experience is that portions of three/four trees is not unusual.

Indeed, and sometimes one of the links will be an entry from a searchable private tree.