Do you want to confirm your DNA connections?

+15 votes
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(For DNA newbies) If you have entered your DNA test, you should have a DNA Connections section on your profile. If it lists people other than yourself, they have also taken a DNA test. 

A "DNA connection" indicates that you have a common ancestor and that if your mutual DNA tests, when compared, indicate that you share enough DNA with them to confirm your genealogical relationship to them, you may be able to mark the status of some of your genealogical relationships as "confirmed with DNA." 

To find out more about how to do this, check out the DNA Confirmation guidance in the Help for DNA Confirmation

in The Tree House by John Kingman G2G6 Mach 2 (27.5k points)
Thank you John. I now have my project of the day!

A "DNA connection" indicates that you may have a common ancestor. Actually, the people listed under DNA Connections are WikiTree members who have tested their DNA and who could have an ancestor in common with you, if both of the lines to the common ancestor are biologically correct. The fact that a person shows up under DNA Connections does not guarantee that you share a common ancestor or that it is the one you expect.

Hi Bennet George

I think you make an important point what if someone in my line is not correct and that person or someone above them is the common ancestor showing that we have a confirmed DNA relationship. What would be a helpful next step?  And how can we avoid this error?
Sharon,

If the genealogical relationships are incorrect, then the genealogy needs more research to find the error. DNA might be able to help confirm or disprove the connections, but solid sources are best.

The purpose of DNA confirmation is to confirm the genealogy, after all.

Hi Sharon,

If you believe that there is an erroneous confirmed DNA relationship on a profile, I'd suggest looking at the required associated DNA source confirmation statement on the profile, which should give you an indication who confirmed the relationship and you can contact that individual to discuss. You can also post a comment on the profile regarding a potential erroneous confirmed DNA relationship.

In reviewing your compact tree, I don't see any of your recent ancestors having a relationship that is marked as "confirmed with DNA". Can you share with us where you believe the erroneous confirmed DNA relationship is?

Hey John Kingman ... just seen we are 7th cousins 2R. We share closest MCRA Thomas Green-704, your 6th my 8th GGF.  I knew we would come up related someplace just scrolling your profile, Magna Carta (I'm related to all, and Mayflower directly to Cole of Plymouth). We probably have additional cousinships. Thanks for your work on Wikitree, and posting the links on how to use the confirmations.

2 Answers

+5 votes
I agree that DNA is important if you want to fine the right connection in family ID, how ever one problem is that most people limit themselves to one Test, because of several companies to. choose  from You can not reach the most people with just one.  First, male. Take a Y DNA, it gives you connection to the all male line.  It is passed from father to son and his son and so on, And the sons DNA is in his mother.  Female Mtdna is mother to daughter and the female line.  I went with FTDNA because they are good in that area. But I limit my connection,  so I went to. Ancestry uses a different type to connect with both sex’s,  it is a lot called. Autosomal . I found my Daughter in Ancestry. Then I went to Myheritage, there I found my son.  Both kids used different sites.. I reached more of the population and found a few 1st cousins. Connected with one I have not seen in 15 years,  me I am trying to find who my father was. The more 1st cousin I Find I may get the answer. Now these  company’s also have more types depending on what you are looking for. So don’t limit your self use at least three.
by Alfred Smith G2G6 (8.5k points)
Congratulations Alfred!

 I figured out my husband's Birth father and Grandfather, a surname change again as his birth father didn't know his father. Using results from various.  We call it fishing in all pools.  Still looking for 3 of my birth siblings . Don't forget 23&me and Gedmatch which takes results from the other testing services combined.
Thank you Morrison. I know nothing of 23 and me. Could they help?

These articles may help you decide what DNA tests could help you.

The work horse test for matching DNA is the Autosomal one.  It is accurate to about 4 generations.   Y is for males only and can go back thousands of years so you often see surnames that make no sense to you because they are so far back.     MtDNA traces the mother's side.  It is not as helpful as Y for the males but can exclude someone from a line.  

But if you are looking to find close relations I would start with the Autosomal test.  It is the one we use the most as Adoption Angels.
I agree. But I still say don’t limit your sources in trying to make connections to the most people in the population. Use at least 3 of the companies that do DNA and three different types. y,  mtdna,  autosomal,. The military uses DNA from the mother to. Identify unknown soldiers who died on the battlefield.  I used one and my kids used a different one each.   We never connected until I used there company. Plus some 1st cousins.
Yes Alfred, it is just another testing service.  It is also the one helpful for medical information held in your genetics.   I was lucky to find my birth family , it made me make decisions that most likely saved my life.   So just another reason to fish in that pool for relatives and get medical advice too.   Laura is correct about Autosomal being the  best test.  Then you need a genealogy sevice like Ancestry or My Heritage where you can build out private test trees of all the descendants of your matches.  I was forced to use 3rd cousins matching on my husband's birth father's side, took from 2007 to 2015 to even get matching that close on his father's side as many people hadn't even tested.  At least now the chances of getting a fairly close match , cutting down on the research, is pretty good!
Many people we work with have limited finances.   By far the least expensive test for genealogy is Autosomal.   Generally you xan download the raw data and upload it to other matching services including Gedmatch, Geneanet,  Genetic Affairs,  MyHerirage.  Those are free to upload to.   FTDNA allows uploading from other labs for about $19 last time I checked.   The more places you can use fir matching the better.   Y and MtDNA are more costly and there are differences of opinion as to how valuable they are for genealogy mainly because they don't have the level of testers that Autosomal has.  I have people who I help who have very few Y matches or MtDNA matches but have thousands of Autosomal matches.
I agree with most with what everyone said, we do everything we need to do to find the facts and information. The biggest problem is trying to get the cousins and others to answer your text for information. I have two 1st cousins who could  shine  the light on my search For a family member.
Alfred I agree , it's gotten close to impossible to receive a message back.  I have 2 first cousins on my birth  mother's side , both of which I have even met IN PERSON, before.  And neither respond to messages on Ancestry or 23 and me to share DNA and genealogy stuff. I think many people got tests as gifts and only tested and check results once for one reason, and ignore everything after they get what they wanted.
+1 vote

Laura (Bozzay), you wrote: 

The work horse test for matching DNA is the Autosomal one.  It is accurate to about 4 generations.

That statement isn't correct, it goes back further and was already discussed many times in this forum and other places but unfortunately wrong information like this gets copied over and over again.

As Darlene Athey-Hill wrote here

Autosomal can go back up to ten generations.  Generally you won't be able to determine matches back that many, though.  But it does happen.

To answer this question I refer to the studies done by Speed and Baldwin which is explained nicely on the ISOGG homepage

A study by Speed and Balding (2014) using computer simulations going back for 50 generations showed that over 50% of 5 mB segments date back over 20 generations, and fewer than 40% of 10 mB segments are within the last 10 generations. Larger segments can still date back quite some time and it was found that around 40% of 20 mB segments date back beyond 10 generations.[4] Figure 2 from this paper showing the distribution of IBD segments of differing sizes by age is reproduced below. (Note that these simulations were based on megabases. As a general rule of thumb one megabase is equivalent to one centiMorgan.)

by Andreas West G2G6 Mach 6 (60.4k points)

Andreas m source is also ISOGG under the ACCURACY headig on this page

 https://isogg.org/wiki/Autosomal_DNA

My statement said "Generally"  not "Always"

I do not want to give people false hope and generally we are cautioned to look for more false matches as the DNA total cms diminish.  I like to set more realistic goals for people who are desperately looking for family.  Can someone luck into a DNA segment past 4th cousins that works?  Yes but even ISOGG cautions it needs more work to verify it. 

Additionally this Vanderbuilt University presentation says Autosomal is good to about 5 or 6 generations.   https://www.vanderbilt.edu/olli/class-materials/DNATesting.pdf

I have seen entire branches disappear at the 4 or 5 generations level. or become so diluted you need to question the matches shown.  When you run a one to one comparison at the chromosome level you  see matches in this range have fewer sufficient chromosome overlaps than at closer relative levels.    

You can perform triangulation as far back as you want. It just makes it impossible to determine who is the common ancestor and how exactly the DNA was inherited (meaning along which exact path).

I'd like to bring your attention to Itsik Pe'er (who helped 23andMe on their algorithms) and his wonderful presentation about Identity by descent in medical and population genomics.

You can see in his work "The Genome of Netherlands" that he has identified IBD segments down to 1 centiMorgan which go back to an estimated 2200 BCE (unfortunately I still can't post pictures here on WT).

Please have a look. IMO it's not discouraging people to educate them right about science and a statement like you wrote is still just wrong (and note that my quote doesn't contain any "generally") and will be then copied over and over again. That's not helpful for the community or for spreading scientific knowledge about genetic genealogy.

I know you had no intention to spread false statements but like I pointed out in the peer-reviewed work linked in my answer autosomal DNA is accurate way beyond (!) 4 generations. Oh and 4th cousins isn't equal to 4 generations, that can be easily misinterpreted as well. Fourth cousins share a 3rd-great grandparent (5 generations), see.

Also, you're mixing things up in your recent answer. Triangulation is accurate, if you do follow all the rules set in place then IBD segments even of very small size (again, reference to Itsik Pe'er work) are validating the ancestral DNA was inherited from a common ancestor (albeit far back). So this has nothing to do with more false matches for smaller segments. All these statistics done are focusing on a threshold where the common ancestor is. So when it's written "false match" or more clearly IBS (identical by segment) it means that the common ancestor is outside (!) the genealogical timeframe that all DNA testing companies are trying to aim for.

Or why do you think do we have Neanderthal and Denisovan DNA in us? As per what most people misunderstand, those would be false matches, right? As the amount of shared DNA is too small. Yet, that DNA was inherited over the last couple hundred thousands years and more.

"Wrong matches" is something that happens when people don't know how to do triangulation and use tools like GEDmatch where you can easily trip by entering the wrong parameters.

As for Associate Professor Itsik Pe'er from the Columbia University you can find his impressive research brief here 

I , for one , have spreadsheets of cousins (12) in one case.  That all share 5 to 3 CMs.  We are all only related in one set of ancestors.  We all fall together on chromosome 5 in overlapping segments, and the women in the group also share segments on chromosome 22 , and small other various. Our trees all match up.  But, it hasn't helped find the 4th great grandmother, because of the lack of any records.  So, that is where traditional genealogy digging meets DNA.  I personally don't believe that there is a chance these small segments are only identical by chance or state, but some experts now argue that you should throw away everything below 7 CM.  I believe you are throwing out valuable information exactly in the generations most of us hit a brick wall. You just have to use the matching correctly, you are correct there Andreas.   Another educated lady on DNA and I both  got in trouble with a project manager on another site , not Wikitree,  for use of small segments in the chat.  But if used correctly I still believe they hold valuable information.  And even this project manager previously taught us how to use them in lessons:)

Thanks Loretta for your valuable comment. Yes, unfortunately we can hit the wall very quickly when documents no longer exist. I have that for my Italian ancestors in Asiago, where WWI destroyed the church books.

But on the other hand we do have very old church books in Germany starting early 16xx and therefore I have an example where I can link the DNA for 4 people to a common ancestor couple born before 1670 in a small, remote village.

I have another TG where we're getting into a similar time range with the "normal" threshold with what 23andMe predicts as "4th cousins" (can you imagine how far back their "distant cousins" are?). Again, scratching luck as I'm again working on the earliest members of the church book pre 1700 to find the missing links push the MRCA's further up.

I do like the work of Jim Bartlett who came up with that term of "walking the ancestor back", meaning you go from one MRCA further up and try to then build the descendants branches out until you hit more DNA cousins from the same triangulated group.

This is how it should be done IMO.

I illustrate the method in this video: 12 steps to identify your common ancestor

While this is showing the app I wrote using the methodology, most steps can be manually done as well. It's about working with our DNA cousins, reach out and communicate to them, building trees for other people to eventually merge them with either other DNA cousins or our own tree. All with that goal to identify the CA.

In your case it didn't work to name the ancestor but at least you know about the location and rough time frame your ancestor lived in. I think that is a partial victory as well and it teaches us a lot to know from history what our ancestors when through so that we can roam this planet now.

As a completely unscientific and inconclusive experiment regarding small segments, this is one I've posted before on G2G and, to be clear to the moderators, I'm perfectly fine with my GEDmatch kit number being shown publicly.

Probably not applicable if you are of a different global-level population (e.g., Asian, Pacific Islander), but otherwise if you have a kit on GEDmatch go to the "One-to-one Autosomal Comparison" and use my kit number: QJ297469C1...and your own kit (or anyone else's you'd like to compare).

The centiMorgan threshold was raised to a minimum of 3cM following the merging of the Genesis database, so choose 3cM for "Minimum segment cM size." Just leave the default "SNP window size threshold."

Give it a go and see if GEDmatch indicates I might match you at that 3cM level. I'll reserve any comment until Hurricane Laura is through with my part of the country and I see if we have a stable power grid back up and running...

When I drop the minimum segment size to 3 cM, GEDmatch says we share 31 cM across 9 segments, with the largest 4.2 cM. Searching 30 generations we have 182 common ancestors and our closest match is 16C3R. So how do we figure out which of those segments come from which of the 182 ancestors? Stay safe during the hurricane!!
Kay, matching isn't triangulation. So you need to find others who match both you and Ed and then based on Itsik Pe'er presentation the common ancestor can be anywhere from 300 CE (Rome was still very powerful back then) to 800 CE (that's when Charlesmagne became the Emperor of the Holy Roman Empire).

Many people will argue it's a waste of time as per other research papers basically everyone with Western European background will be a descendant from Charlesmagne.

In order to figure out which segment comes from whom you, Ed and the other DNA cousins in a triangulated group need to start with the earliest (most recent) common ancestor. That will be your anchor from which you then go further back and extend the sidelines downwards to eventually connect more DNA cousins to it. Then you have a new MRCA which is hopefully further back.

I've just had 2 DNA cousins in a TG that are 2nd cousins. I could identify their connection and then work upwards. That's why it's important to look at those connections between DNA cousins that are closest first, they don't have to be connections of yours as long as they are in the same TG.

That's key. As a German by birth most of my matches are far back in time, so instead of just giving up searching I apply that method and thanks to the very old church books and the Ortsfamilienbücher (a book written about all birth, marriage and death events at a church/village(s) with most being assigned to family structures) I can work with my DNA cousins slowly upwards until it hits German soil and then it becomes very clear due to the location where to continue (and the German surnames of cause).

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