Is tagging others with DNA results proper?

Question

It appears that my son (he owns his own WikiTree profile) took a DNA test. Apparently an 8th cousin tagged everyone between him and them (missed his and mine, I guess since still living) including a detailed post that includes a link to his profile.

This seems invasive. There are whole lot of profiles in between with active profile managers.

And how reliable is an 8th cousin relationship?

Is this accepted practice?

Edit: Apparently the perpetrator of this particular tagging has done it for at least a dozen "relatives" so far and has gotten some pushback. And a fairly recent WikiTree-er.

Would it be proper/appropriate to undo those edits for the profiles I manage?

Comments

Personally, no, I don't think what you have described should be done. Oh my, what would happen if everyone did this?! We might all have potentially thousands of such tags on our profiles.

As far as reliability, I think this help page tells that WikiTree considers up to 3rd cousins or less relationship enough reliability for basic DNA confirmation. Beyond 3rd cousin would require triangulation (at least three people) for confirmation of DNA. 8th cousins don't share enough DNA to confirm relationships, I don't think, from what I've read here and elsewhere.

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Well, I checked, and there are three 8th cousins whose lines converge on the common ancestor, not before, so by the "Triangulation rules" in the DNA rules, this would be valid. But still, 8th cousins?

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Based on what I see on the profile linked below, he appears to have done the triangulation statement correctly. I am surprised that 8th cousins met the threshold for triangulation. I suppose, in a way, this is a good thing--confirms your common ancestry via DNA--and perhaps I should withdraw my initial criticism. I didn't realize when you first posted that he had posted a triangulation statement which is permitted. When you said he was "tagging" I envisioned something completely different.

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There are multiple MRCAs for the three lines. That makes it more questionable.

Answer 1

Could you explain a little more what you mean by 'tagging'?  The reason I ask is that the DNA percentages you see on profiles is done by the system, not by an individual.

Comments

Well, for example, here's my great grandfather: https://www.wikitree.com/wiki/Willcox-554 

Each profile shows a little DNA icon next to the "confirmed" parent, and then there's a big comment block starting with "Paternal relationship is confirmed by a triangulated group on 23andMe who..."

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That is the approved Wikitree method for annotating profiles with relationships confirmed by DNA.  I'm don't think it's possible to accurately triangulate a relationship that far back. If you add the "DNA" tag to your post one of the DNA experts here may be able to explain whether it's possible or not.

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Yeah, 8th cousins seemed pretty tenuous.

I didn't see the DNA tag until after I posted this. Is there a way to add a tag to a post after the fact? I can't find it. I may need to re-post.

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Immediately under your question is a link in tiny text: 'edit'.  
Click on that and make the changes, then save.

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Just found it. I was looking for a drop-down list or something instead of just typing.

Answer 2

They did add a DNA confirmation statement.   ""Paternal relationship is confirmed by a triangulated group who share a 9 cM segment on chromosome 2""   Only one of the three are listed on GEDMATCH so I don't see how they knew that the matching segment was on chromosome.   
I'm not convinced that this is anything close to proof.

 

Comments

I'm a complete ignoramus on this whole DNA matching thing, like how it works and how GEDMATCH figures in.

The general concept, yes. But how the matching is done, and what's considered significant, and what GEDMATCH has to do with it, no.

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The three people in the triangulation all used Ancestry's autosomal DNA  test.  Ancestry does not offer a "chromosome browser"    To do a comparison that finds matching segments on a particular chromosome they all would need to export their raw DNA data to a place like Gedmatch.   Lets say they all did in fact share a matching segment, then the task is to determine which common ancestor contributed that DNA.   Unless they all share only single ancestor in common this last part can be difficult.

These three people are 7th+ to each other.  Autosomal DNA is not very useful in determining relationships beyond a few generations.

Answer 3

I didn't look at the genealogy; as long as all lines are well sourced, it looks good to me. It is not easy to successfully triangulate, and you should be happy that someone has been able to do so. All have Wikitree profiles, and all descend from different children of the common ancestral couple. The statement does not say anything about GEDmatch; instead, it says 23andme. I do not have a 23andme account, so I can't go check to see if all fall within the estimated relationship range. As long as the three of you don't also share another ancestral couple, one common 9cM segment shared by all proves the segment had to come from that common ancestral couple. I say congrats!

Comments

As long as the three of you don't also share another ancestral couple...

That's the catch. We don't know that there's not another common ancestor, either unknown to WikiTree, or farther back and not an ancestor of the current common ancestor.

"All descended from <person>" and "All share a DNA segment" does not prove "Said DNA segment came from <person>", and therefore doesn't verify the "descended from" is true, or that all of the parental relationships between are true.

I guess it's a good guess that all three are relatives, but by that particular path is plausible but tenuous.

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Don't take what I said out of context. Good luck to you going around and around with your logic. For some reason, you question that many generations, but you think there may be other common ancestors further back who passed the DNA to those three. What I said holds up; all conditions have to be met.

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Well, I beg to differ. My logic is quite linear.

I'll concede that the DNA match may be a legitimate indication that people are related. I don't know enough about the technology to know how closely related, but let's assume it can says "approximately 8th cousins."

What I'm saying is that without complete knowledge of every ancestor of the three, nobody can assert for certainty that that particular common ancestor and only that common ancestor is the source of that DNA bit for all of them. For example, maybe two are also descendants of two siblings of a parent of that common ancestor, by very different paths.

Or one of them might even have two lines back to that common ancestor. Who knows, then, which path carried that DNA?

So yes, the DNA match can tell you "It looks like you're related to these other people." And knowing that, it can be interesting to ask "So how am I related to these people?" WikiTree would be helpful answering that question. It might even be able to show more distant relationships.

But without perfect knowledge (especially at this distance), there's no way to prove that that DNA bit was inherited along a particular path, so calling all of those parents "confirmed with DNA" is at best weak.

I, for example, know of several ancestors I'm descended from over multiple paths, some that don't converge for 4-5 generations. If one of those ancestors was on my line to the common ancestor of us three, which line would be considered "DNA verified."

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Oh, and just to be clear, I don't think I mentioned GEDmatch. Not in my original post. That came up in another answer. Again, not being much on the matching technology or services.

Maybe some of those systems (23andme, GEDmatch, ... and maybe those aren't even equivalent things) are more reliable than others. But I don't think that's relevant to the question at hand.

Answer 4

For the triangulation described on https://www.wikitree.com/wiki/Willcox-554, only one of the three WikiTree members have added their own DNA tests to their own profiles. The author of the triangulation "confirmation" shows as having tested at 23andMe, AncestryDNA, and FTDNA.

To me, that's a question of appropriateness that I'm not sure WikiTree has ever directly addressed, i.e., if a member does not choose to add their DNA test information to WikiTree and yet another member is able to identify them and their WikiTree IDs via matching results at a testing company, is it appropriate for the members who do not enter their DNA test information to ever be used by another member in a "Confirmed with DNA" statement?

My opinion is that the answer to that question should be a resounding "no." If the "triangulator" wants to use those individuals, I think they should be treated/documented as non-WikiTreers. In other words, the data can be used but the individuals cannot be identified, which means the "Confirmed with DNA" status can be applied only on the "triangulator's" direct line and never include the others.

I believe my conservative view of autosomal triangulation among distant cousins has seen way too many words expended here already, but I'll say again that there has never been any reputable, peer-reviewed research published that indicates it should be a valid methodology. There are reasons why the technique--if used properly and with full understanding of how to analyze the data, including evaluating the segment against heterochromatic areas of the chromosome and both population-level and haplotypic pile-up regions--should be productive among closer cousinships. But beyond the level of 5th cousins the biology and math virtually scream that with our inexpensive microarray tests it should be a statistical anomaly if it ever happens, something that should very seldom be possible with any degree of accuracy.

WikiTree, however, does not place a limitation on the generational distance for autosomal or xDNA triangulations. So that opinion doesn't count. I will say, though, that I've been at this genetic genealogy stuff for over 22 years; my first DNA test was for an alma mater's yDNA research study. And I've never been willing to accept as positive evidence any autosomal triangulation more distant than the inclusion of 4C1Rs. If I have sufficient data--sometimes necessitating analysis of the raw DNA data files themselves--I have yet to be unable to cast doubt on an autosomal triangulation attempting to reach farther back than that.

I'll also note that DNA evidence ranking is on a fluid spectrum from "very strong" to "very weak." It has to be underpinned by traditional genealogy, especially as the DNA evidence grows weaker. Pedigree collapse is in all our lines; it's inevitable. As we go back in generational time, the amounts of shared autosomal DNA become drastically smaller. If you have solid documentation for your and your 3rd cousin's 2g-grandparents, you're on pretty solid ground.

But as you move back generation by generation it also means that your scrupulous detail about all potential genetic inheritance pathways becomes more and more important. And more and more complex and difficult to achieve.

For example, a regional population bottleneck--say, for example, early emigrants to North America--brings with it, via a property of meiosis called linkage disequilibrium, a much higher likelihood that identical chunks of DNA were spread throughout that population as it grew. Small segments of DNA may very well be pervasive among people living today who are descended from that founder population. Genetic recombination is not so random as many believe.

The triangulation shown on Willcox-554 references an MRCA couple born 1690 and 1691 in Connecticut. The shared DNA amounts themselves are small enough to be questionable and, considering that some testing companies have suspended the reporting of chromosomal detail, we can't know if the indicated segment size is actually the segment shared by all three test-takers. However, it's almost a certainty that the MRCA couple, Samuel Buell and Abigail Crittenden, were of similar regional stock in Britain (note that Samuel was the grandson of a Puritan Great Migration immigrant, and Abigail was also second-generation Puritan Great Migration; their born-in-England ancestors date back to the 1590s).

These founder population bloodlines are so intertwined that it would be all but impossible for living descendants to successfully unravel which bit of DNA originated with which ancestor, even if the physical DNA segment can pass the basic biological analysis.

We'd be roughly 10 generations back with those original Puritan Great Migration immigrants. Simulations done by Dr. Graham Coop at U.C. Davis indicate that--even without the population bottleneck of the founder effect--at 10 generations the typical family tree will have not 1,024 unique ancestors but only about 1,008. The other 16 will have passed their DNA down the line via more than one inheritance pathway.

Comments

There are multiple pathways for the DNA to have occurred. The three people used for the confirmation are related to different MRCAs. Wikitree needs to tighten up what is and isn't a valid triangulation.

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I apologize, I guess I should have asked but  thought someone would be happy that someone could find dna relatives for them. You could of just messenged me that you didn't want that on there instead of making a fuss. I will take it down. If I forget any feel free to edit them out as they are hard to back track without doing the same triangulation again to view. Guess some cousins don't want to be cousins, not sure why you joined if not looking for family.have a nice day.

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I agree, Doug. But I'm also sensitive to the challenge WikiTree faces. Even as oversimplified as the current "Confirmed with DNA" requirements are, we not infrequently see members expressing difficulty understanding and following them. So it's a rock and a hard place: marketing versus accuracy.

Irrespective of the privacy issue I described, I also strongly feel autosomal triangulations among 7th and 8th cousins as described in this thread are, scientifically, highly improbable with any degree of accuracy.

I've used the terrible analogy before that working with autosomal DNA for genealogy is a bit like medicine. Anybody can disinfect a scraped knee and put a Band-Aid on it. Using our typical DNA reported results out through 2nd cousins--great-grandparent MRCAs--is like that.

By 3rd cousins, approximately 8% to 9% of them will share no meaningful amount of DNA with us so our matching "range" effectively starts at zero. It takes a bit more background in biology and more genealogical research to deal with them to a degree of certainty. Now we're at the level of first-aid where we have a laceration rather than just a scrape.

When we get to 4th cousins, only about 48% of them will share a reasonably detectable amount of DNA with us, and the theoretical average sharing is down to 0.196%, or roughly 13cM. Now we need some fairly extensive first-aid training because we have to splint a broken bone and control any bleeding, and we'll also need an experienced physician to set the break and manage treatment. By 3g-grandparent MRCAs we're already at a level of complexity that really can't be distilled down to a simple, standardized if/then procedure.

By 5th cousins, we're scrubbed, gloved, masked, and in the operating room surgically removing an appendix. No Bactine spray and Band-Aids now. You gotta know what you're doing. Any two 5th cousins will be a detectable match only about 15% of the time. Simple statistics, then, tells us that finding any three 5th cousins who match each other would be a probability of around 0.0225, or 2.3% of the time. That places the odds of it happening at approximately 44-to-1.

But wait; there's more.

For a valid triangulation we need at least three cousins not just sharing DNA: they need to share some of the same DNA from the same MRCA. This means significant, overlapping segments that can be confidently traced back to the MRCA. That changes the game. Instead of a 15% chance of finding two 5th cousins who fit the criteria, we need to halve that to 7.5% because any two children of the MRCA couple (except identical twins) will carry only about 50% of the same parental DNA. That drops our probability of finding an accurate triangulation for three cousins to 0.005625, or about 0.57%.

Because each level of full cousinship decreases the expected amount of shared DNA by a multiple of 0.25--e.g., 3rd cousins will share only about 1/4 as much DNA as 2nd cousins--we go really quickly from "anybody can apply a Band-Aid" to "we've got a full ER surgical team on this and the prognosis is not good." By 6th cousins--5g-grandparents--the probability of success is already down to 4.41x10^-4, or 0.000441, 0.044%...odds of 2,273-to-1. And we haven't even introduced pedigree collapse into the mix.

Things get quite complex quite quickly. There is no way that WikiTree can establish a simple criteria or procedure (and hope to retain a measure of probable accuracy) for autosomal triangulation among distant cousins. One size does not fit all.

I think the best solution, though it would likely be unpopular, would be to restrict the current triangulation instructions to MRCAs no greater than 4g-grandparents. Going back six generations would be permitted, but autosomal "Confirmed with DNA" could no farther.

An alternative would be to increase the minimum shared segment threshold to 15cM, preferably even a bit higher. There has never been anything remotely magical about a 7cM cutoff. I believe the origin of that minimum was a misreading of work done over a decade ago by John Walden where he found that, when using phased results from one parent, a reported 7cM segment survived the phasing 63% of the time. But what's key is that when the phased results from both parents were considered, 7cM segments proved to be false 58% of the time.

We have a large number of "Confirmed with DNA" status markers on WikiTree that rely on autosomal triangulation among distant cousins. My guess is that nearly all of the ones using 6th cousins or greater cannot stand up to close scrutiny. But I also think the ship has already sailed and that it's unlikely we'll see a significant revision to the triangulation policies.

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@Terrie: It wasn't my Question and I have no relationship to, or interest in, the profiles involved. I'm simply one of the resident DNA geeks and was commenting from that perspective only.

However, I believe the original author of this thread should see your reply here. To be certain, though, you might want to send him a private message from his WikiTree profile.

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Thank you, Edison. You are probably correct that we are stuck with what we have. There could be some minor tweaks. One I would like to see is that if there are multiple paths for DNA to enter then you can't confirm. That is, if the relationship finder can find more than one set of ancestors that would work for an MRCA. For this particular case there is at least one additional way they are related that doesn't involve the subject of this post so I don't see a way to confirm.

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Thanks, Edison,

Your note confirms my own doubts about "suggested matches" from certain DNA test companies, 3 different companies have (1) confirmed my sister as such - I was there when she was born, (2) identified 2-3 second cousins traceable within the family, (3) found a matching cousin who I shared a GGrand/Grand father with solving a brickwall, and I expect many other WTer's will experience similar "solutions" via DNA testing, but when the company suggests 17,000 matches at 0.1% or less including some from corners of the globe so far removed from our generally traceable ancestors I feel one is entering LA-LA land if one believes them - but how to filter for meaningful % results doesn't seem to fit with their Business Model.

I am reminded of the old adage " How do I get to X (choose a place)" the answer was "Don't start from here!" , and tracking along a DNA pathway can deserve the same advice.

Answer 5

This isn't really an "answer," just where I've settled after all of this discussion (and an exchange with the member who made these changes): While these "confirmed" DNA relationships are interesting, especially this far back they're pretty weak. Including the confirmations in profiles, including open profiles you don't manage, is acceptable. It's equivalent to adding a source, though (particularly in a case like this) pretty weak.

And a couple of profiles that were modified were "Open" instead of "Public." I've fixed that.

So I guess adding that "DNA confirmed" flag and a explanation of the match is OK, but I'd suggest the following changes about how this is done:

• When describing the match, don’t mention any individual without obtaining explicit permission. Instead, say something like “A great grandchild of [[surname-23|Ancestor With Surname]]”, where Ancestor is the DNA matched person's closest open ancestor. (Or use the closest ancestor that gave permission.)
• Is there a way to put that big description in one single place and link to it elsewhere? 
  • Maybe a RESEARCH NOTE or SOURCE in your profile and then link to your profile? (You could say something like “<ref>DNA MATCH #XYZZY in [[wiki-id|Person Name]].</ref>")
  • Or a PDF attachment in your profile; then you could link directly to the document?

Comments

The Triangulation tool is the one who comes up with how it is worded. All I did was follow instructions on where to put them. I didn't write these myself. I sent you a message back explanning this. Maybe the Triangulation maker needs to word it different? But if accounts are closed that you don't want edited, that will take care of this anyway, but will also prevent informative info someone might have about that said person to not be posted as to learn more about them you might not have known.

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I understand that you used the template suggested for the tool, I get that that that appears to be how you describe the connection to someone who understands all of that verbiage can evaluate the reliability. I just dislike the noise added to all of the profiles. If that information was available by reference for each step in the chain, something similar to my suggestion, that would be better. (Kind of like how most other sources are handled.)

Looks like you removed what added this relationship, including in your own profile. That isn't what I was looking for, but I guess we'll leave it at that.