Why Don’t I Match My Cousin?

no cousin

I receive this question regularly from people who have taken one of the autosomal DNA tests and who expected to match a cousin, but don’t.

Of course, the Jeff Foxworthy in me wants to say, “Because he’s not your cousin,” but fortunately, I never let my inner Jeff Foxworthy out in public.

Actually, that’s often their biggest fear – that they are uncovering a very unpleasant family secret – but Jeff Foxworthy aside – that’s generally not the case.

Let’s take a look at why.

According to Family Tree DNA’s FAQ on the subject, combined with the percentage of DNA shared with each type of cousin, we find the following.

Relationship to You Likelihood of a Match % of DNA Shared
1st Cousin (common grandparents) 100% 7-13
2nd Cousin (common great-grandparents) >99% 3-5
3rd Cousin (common great-great grandparents >90% .3-2
4th Cousin (common ggg grandparents) >50% <1%
5th Cousin (common gggg grandparents) >10% Sometimes none detectable at match threshold
6th Cousin (common ggggg grandparents) <2% Often none detectable at match threshold

If you don’t match your first cousin, then you need to start thinking about Jeff Foxworthy or you’re simply extremely lucky, or unlucky, depending on your perspective.  Buy a lottery ticket. 

In all seriousness, if you don’t match a first cousin, consider having your sibling (or parent) or your cousin’s sibling or relevant parent test as well.  In some cases, two people simply inherit different DNA and even though they don’t match each other, they do match other people in the same family. 

However, if you’re going to go down this path, be prepared that the answer may be that you really aren’t genetic cousins.  By the time you get to this point, you’ve already peeked into Pandora’s box though, so it’s kind of hard to shut the crack and pretend you never looked. 

Another option for determining whether or not you really match that cousin is to download both of your results to GedMatch.  The testing companies have pre-set match thresholds that determine what is and is not a match.  That’s a good thing, but what if your match is just slightly under that threshold, and there aren’t other relatives to test?  GedMatch allows you to match at very small segment levels that would generally be considered population matches and not genealogy matches.  

Judy Russell had the perfect example of just this situation in her Widen the Net blog.  Her mismatch was with a 3rd cousin.  According to this the chart above, she stood a greater than 90% change of matching, but she didn’t, so she’s in the special 10%.  And that 10% gets left wondering.  Fortunately, Judy had tested aunts, uncles and another first cousin, and her cousin who did not match her did match them. 

The moral of this story is:

  • Ignore Jeff Foxworthy when he starts to whisper in your ear, at least initially
  • Test as many family members as you can
  • Don’t jump to conclusions
  • Utilize third party tools like GedMatch if necessary
  • Understand that if you test enough family lines, you will eventually find an undocumented adoption someplace

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

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Happy First Blogiversary

may you live in interesting times

Today is the first anniversary of the launch of www.dna-explained.com.  In a way it seems like just yesterday and in another way, it seems like DNA-explained has been a part of my life forever.  One thing is for sure, it’s been a very interesting year!

So now, I’m going to tell you a secret.

I was going to retire early and write a book.  I was going to have time on my hands.  I was going to work on my own genealogy and share the journey of what I learned.  I was going to weed my garden.  Are you laughing now?  Holding your sides?  Well, if so, you clearly understand just how unrealistic that expectation was.

I have less, much less, time now than ever.  My little part-time retirement job overtook my original career, and then some.  I’ve never worked harder, had less sleep, nor loved it more.  Is sleep really a necessity?  Seems like so much wasted time.  Spoken like a true genealogist!

Genetic genealogy is the marriage of my two passions, genealogy and science.  I spent my entire career on the very exciting edge of technology, first communications research and discovery, then mapping and specialized software.  Genetic genealogy isn’t much different actually, except it’s more bleeding edge (some days) than leading edge and it’s much more personal and fulfilling.  Not only have I learned volumes about my own ancestors – things there was no prayer of knowing even a decade ago – but I get to help others on that journey too.  Not only that, but I’ve gotten to be personally involved in scientific discovery.  I can’t imagine a better place to be!

And no, I’m not writing a DNA book.  Well, actually, I am, soft of – but just in a different way.  Blogs are the way of the future – so is electronic communication.  The problem with books about fast-moving and highly technical topics is that they move on and change so rapidly that tomorrow, literally, your book can be out of date and you have no way to update it.  Just what I don’t need is another box of boat-anchors in my office.

Not long ago, someone on the ISOGG Facebook page asked for a list of books and someone replied, “forget the books, read the blogs.”  I don’t want to invest the effort into one of those “forgotten books” when the blogosphere beckons and is so much more friendly towards photos, graphics, color and change.  It’s also a lot more personal and flexible.  And it lets me interact with you and vice versa .

So how have we done this first year?  As of yesterday, we surpassed 2100 subscribers and that doesn’t count all of the RSS feed, Facebook and Twitter followers.  My husband bet me I’d have 2000 by summer and I said I wouldn’t.  Good thing I didn’t bet much, because I was wrong.  Thanks to all of you.  Sometimes being wrong is a good thing!

This is the 162nd posting, so about one every other day.  I had goaled one a week.

There have been a total of about 2700 “real” comments and are you ready for this, almost 29,000 spam ones.  No, that is not a typo.  Yes, I do use a spam filter, but I still approve every single comment that is posted – and now you know why.  The spam filter doesn’t catch them all, because spammers are crafty!

In total, the articles are “tagged” in 81 different categories so you can find them by searching.  One of the articles I’ll be writing soon will tell you how to use and search blogs more efficiently, including this one!

http://www.dna-explained.com has had a total of 249,545 views, nearly a quarter million and that doesn’t count the 2100+ people who receive postings via e-mail and RSS.  We average just over 1000 hits per day now.  Wow!

What is the most popular category of blog articles visited?  Autosomal DNA.

How about the most popular article?  Big News! Probable New Native American Haplogroup.  That shocked me.  For a long time, the most popular article had been the kickoff of the Geno 2.0 announcement, National Geographic – Geno 2.0 Announcement – The Human Story published on July 25, 2012.  Older articles have more time to amass hits – and the haplogroup article was just published June 27th.  Indeed it does seem to be big news and is of interest to lots of people.

One of my reasons for creating this blog was as a matter of self-defense.  I receive a lot of inquiries through my various list memberships.

So I decided that if I wrote the answers to the most frequently asked questions, well, including graphics and pictures (which really are worth 1000 words), once, I could use that document to answer people’s questions, over and over again.  The good news is, so can you.  What are the most commonly asked questions and the pages I use to answer them?

  1. What can DNA testing do for me?  That is such a basic question and the answer could be that book I didn’t write.  I use the article 4 Kinds of DNA for Genetic Genealogy to answer this one.
  2. I think my ancestor was Native American and I want to prove it.  This question also has other variants like, proving which tribe, joining a tribe, getting benefits and free education.  I refer people to the article Proving Native American Ancestry Using DNA.
  3. I’m adopted, or I don’t know who my father is, and I want to use DNA testing to find my parents/ancestry.  This is also relevant for people who discover an undocumented adoption in their line that “interferes” with the genealogy they thought they knew.  For this answer, I use I’m Adopted and I Don’t Know Where to Start.  This article, along with many others, links within the article to other resources as well.
  4. What can autosomal testing do for me?  If I had a dollar for every time I’ve received some flavor of this question, I’d be really retired and on that World Cruise!  The article I use for this is Autosomal Basics.
  5. And then the companion question to the one above, my autosomal results are back – what do I do with them now?  For this one, I refer people to the summary article for The Autosomal Me series.  While it is focused on a particular challenge for me, minority Native admixture, the tools and techniques are relevant for everyone.

We’ve had an awesome first year, thanks to all of you, and I’m looking forward to even more breakthroughs and findings in year two.  I love sharing your stories and victories too and always appreciate tips and hints pointing out genetic genealogy items of interest.  I have some fun articles planned for this upcoming year and there are discoveries on the horizon, so stay tuned!!!

And indeed, may we all continue to live in very interesting times!

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

                       

No (DNA) Bullying

No Bullying

There are hardly any hobbies that hold more passion than genealogy.  Once hooked by the bug, most people never retire and one of the things they worry about passing down to their family are their genealogy records – even if the family of today isn’t terribly interested.

So it’s easy to understand the degree of passion and enthusiasm, but sometimes this passion can kind of go astray and it crosses the line from something positive to something not nearly so nice.

Genetic genealogy is the latest tool in the genealogists’ arsenal, but it introduces some new challenges and unfortunately, with the increased number of people testing, we’re seeing some examples of what I consider bullying – for DNA, for identification and for information.

Bullying is unwelcome aggressive behavior that involves repeated threats, physical or electronic contact or a real or perceived imbalance of power.  Generally, the victim feels they can’t make it stop.  This has become especially prevalent in the cyber age.  And bullying is not just about kids.

I’m going to look at 3 types of situations.  It’s easy to see both perspectives, but bullying by any other name is still bullying, even though the bully probably doesn’t see it that way.  Guaranteed, the recipient does.

You’ve Got the DNA I Need

Let’s say that Aunt Gladys is the last person alive in a particular line who can provide DNA to represent that line.  But Aunt Gladys, for whatever reason, doesn’t want to test.  It’s fine to discuss this, to talk about her concerns, and perhaps you can find a solution to address them, like testing anonymously.

But let’s say that Aunt Gladys simply says “no,” end of story.  What then?

Yes, Aunt Gladys carries the information that you need, but it’s HER DNA that needs to be tested, and if she says no, then her decision should be respected, as difficult as it may be and as unreasonable as it may seem.  Maybe Aunt Gladys knows something you don’t – like she is adopted or some other secret that she does not wish to reveal.  Badgering Aunt Gladys from this point forward is going to do nothing other than cause hard feelings and make Aunt Gladys want to avoid you.

You may think you’re “just discussing” but from her perspective, you may be bullying.  Now, it’s OK to beg and cry once, but if you’re slipped into the realm of “if you don’t test, I’ll tell Uncle Harvey that you scratched his car back in 1953,” you’ve stepped over that line.

Won’t Answer E-Mails

I can’t tell you how often I hear this story.  “I match with person XYZ and they won’t share their information.”  Most of the time, they won’t answer e-mails.  And the question follows, of course, as to why they tested in the first place.

These tests have been around for a number of years now.  Many people have died or moved or the purpose of the test was fulfilled and they aren’t interested beyond that.  Think of your Aunt Gladys.  If you did convince her to test, it wouldn’t be for her, but for you and she certainly would not be interested in answering random e-mails.

There could be a number of reasons, depending on the testing company used, that someone might not answer.  In particular, many people test at 23andMe for health reasons.  It doesn’t matter to them if you’re a first cousin or any other relation, they simply aren’t interested or don’t have the answers for you.

It’s alright to send 2 or 3 e-mails to someone.  E-mails do get lost sometimes.  But beyond that, you’ve put yourself into the nuisance category.  But you can be even worse than a nuisance.

I know of one case where someone googled the e-mail of their contact, discovered the person was a doctor, and called them at the office.  That is over the line into cyber-stalking.  If they wanted to answer the e-mail, they would have.  If they don’t want to, their decision needs to be respected.

I Know You Know

This situation can get even uglier.  I’ve heard of two or three situations recently.  One was at Ancestry where someone had a DNA match and their trees matched as well.  At first the contact was cordial, but then it deteriorated into one person insisting that the other person had information they weren’t divulging and from there it deteriorated even further.

This is a hobby.  It’s supposed to be fun.  This is not 7th grade.

Adoptions

However, there are other situations much more volatile and potentially serious. In some cases, often in adoptions, people don’t want contact.  Sometimes it’s the parent and sometimes it’s the adoptee.  But those aren’t the only people involved.  There are sometimes half-siblings that are found or cousins.

For the adoptees and the parents, there are laws in each state that govern the release of their legal paperwork to protect both parties.  Either party can opt out at any time.

But for inadvertently discovered family connections, this isn’t true.  Think of the person who doesn’t know they are adopted, for example, who discovers a half-sibling and through that half sibling their biological mother.  Neither person may welcome or be prepared for this discovery or contact.

Imagine this at the dinner table with the family gathered, “Hey guess what, I got a half-sibling match today on my DNA.  I wonder if that’s some kind of mistake.  How could that be?”

So if you match someone as a half sibling or a cousin, and they don’t want to continue the conversation, be kind and respectful, and leave the door open to them if they change their mind in the future.  Pushing them can only be hurtful and nonproductive.

Dirty Old (and Formerly Young) Men

And then, there’s the case of the family pervert.  Every family seems to have one.  But it’s not always who you think it is.  By the very nature of being a pervert, they hide their actions – and they can be very, very good at it.  Practice makes perfect.

Let’s say that Jane likes genealogy, but she was molested as a child by Cousin Fred.  Some of the family knows about this, and some don’t believe it.  The family was split by this incident, but it was years in the past now.  Jane wants nothing to do with Fred’s side of the family.

(By the way, if you think this doesn’t happen, it does.  About 20% of woman have been raped, 30% of them by family members (incest), many more molested, and children often by relatives or close family friends.  15% of sexual assault victims are under the age of 12.  Many childhood cases are never prosecuted because the children are too young to testify.  Perverts and pedophiles don’t wear t-shirts announcing such or have a “P” tattooed on their forehead.  Often family members find it hard to believe and don’t, regardless of the evidence, casting the victimized child in the position of being a liar and “troublemaker.”  Need convincing?  Think of what Ariel Castro’s family said and how well he hid his dark side and the Boston bombers’ family comments about their innocence in the face of overwhelming evidence to the contrary.)

Jane’s an adult now and DNA tests.  She has a match and discovers that it’s on Fred’s side of the family.  Jane tells the person that she doesn’t want anything to do with that side of the family, has no genealogy information and wants no contact.  The match doesn’t believe Jane and then becomes insistent, then demanding, then accusatory, then threatening.

This is clearly over the line.  Jane said she didn’t want any continued contact.  That should have been the end of the discussion.

But let’s say this one gets worse.  Let’s say that because of this, Cousin Fred wakes up and decides that Jane is interesting again and begins to stalk Jane, and her children……

Does this make you shake in your shoes?  It should.  Criminals not only aren’t always playing with a full deck, but don’t play by any of the same rules as the rest of us.  Cousin Fred might just be very grateful for that information about Jane and view it as a wonderful “opportunity,” provided by his “supportive” family member who has now endangered both Jane and her children.

Who’s Yer Daddy?

In another recent situation, John discovered by DNA testing that he is not the biological child of his father.  He subsequently discovered that his mother was raped by another male, married to another close family member.  When John discovered that information, he promptly lost interest in genealogy altogether.

A year or so later, John matched someone closely who was insistent that he provide them with how he was related to them.  John knew, but he did not feel that it was any of their business and he certainly did not want to explain any of the situation to the perpetrator’s family member, who, by the way, had already mentioned what a good person the perpetrator was.  However, the person continued to harass and badger John until he changed his e-mail address.

I so wanted to ask these people, “What part of “NO” don’t you understand?”

Mama’s Baby, Daddy’s Maybe

In one final example, adoptees often make contact with their birth mother first, and then, if at all, with their birth father.  Sometimes the birth mothers are not cooperative with the (now adult) child about the identity of their father.  Often, this is horribly frustrating to the adoptee.  In at least one case, I know of a birth mother who would never tell, leaving the child an envelope when she died.  The child was just sure the father’s name was in the envelope, but it was not.  I can only imagine that level of disappointment.

Why would someone be so reticent to divulge this information?  The primary reasons seem to be that either the mother doesn’t know due to a variety of circumstances that can range from intoxication to rape, the woman never told the father that she had a baby and placed the child for adoption, the father was abusive and the mother was/is afraid of him/his family, the father was married, or the father was a relative, which means not only might the father still be alive, the mother may still have a relationship of some type with him.  The mother may have lied for years to protect herself, and in doing so, protected the father as well.

Clearly, this situation has a lot of potential to “shift” a lot of lives and not always in positive ways.  One woman didn’t want to make contact with her child other than one time because she had never told her husband of 30 years that she had a child before their marriage.  One woman made contact, but did not want to divulge that the child’s father was her older brother, still alive.  Victims often keep the secrets of their attackers out of misplaced shame and guilt.  Think Oprah here.  Mother may not be simply being stubborn, but acting like the victim she is and trying to preserve whatever shreds of dignity are left to her.  She may also be embarrassed by a lapse in judgment.  One adoptee realized when counting forward from her birth date that she was conceived right at New Years and when she realized that, she figured out that her mother, who drank heavily when she was younger, probably did not know who her father was, and didn’t want to admit that.

As frustrating as this is for the adoptee, the birth mother does have the right not to have her life turned upside down.  Badgering her will only result in losing the potential for a relationship from the current time forward.  Being respectful, understanding and gentle may open the door for future information.

R-E-S-P-E-C-T

I can hear Aretha now.

If you haven’t walked a mile in their moccasins, so to speak, you can’t possibly know the situation of the person on the other end of your request for DNA or information.  Don’t make the mistake of stepping over the line from excitement into bully behavior.

Think of the potential situations the person on the other end may be dealing with.  Ultimately, if they say no, then no it is and no should be enough without an explanation of why.  Generally bullying doesn’t work anyway, because someone who feels like you are threatening them or being too aggressive will clam right up and it will be that proverbial cold day in Hades before they tell you anything.  It’s important to keep communications from sounding like you’re demanding or entitled.  My mother always said “you’ll catch more flies with honey than with vinegar.”  I always found that very irritating, probably because I needed to hear it just then – but regardless – it’s true.

Keep in mind, genetic genealogy is about genealogy.  It’s a hobby.   It’s fun.  If it becomes otherwise and puts people at jeopardy, then we need to take a step back and take a deep breath.

Most people don’t mean to cross the line into bullying.  They just get excited and sometimes desperate.  Hopefully this discussion will help us all be more aware of where the polite line is in communicating with our family members and matches.

If you are the victim of information bullying, cyber-stalking or someone puts you in an uncomfortable situation, there are steps you can take to remedy the situation.  Most bullying sites are directed at adolescents, but the advice still applies.

If you know you don’t want contact initially, then make your accounts anonymous or don’t respond to requests.  If you realize that you don’t want contact after the initial contact, for whatever reason, say so.  After that, do not engage in communications with someone who is attempting to bully you.  If they threaten you or threaten to reveal information or your identity if you don’t give them information or do something, that action falls into the blackmail realm, which a crime.  Complying with a threat to protect yourself or your family generally only results in more of the same.  You are not dealing with a nice person.  At this point, you are way beyond genealogy and your own internal “danger” sign should be flashing bright neon red.

If disengaging does not take care of the problem, save all messages/contacts and contact your attorney who may advise you to contact the police or the FBI if the problem crosses state lines.  Depending on what state you/they live in and exactly what they have done, you may have a variety of options if they won’t stop, especially if they do something that does in fact manage to turn your life upside down and/or a crime is involved, like blackmail.  Of course, this is akin to closing the barn door after the cow leaves.  Hopefully, the person causing the problem is simply an over-zealous genealogist, means you no harm, realizes what they have done or are doing, and will get a grip and compose themselves long before this point.

Bullying of course is not because of DNA or unique to genetic genealogy, but the new products introduce new social situations that we have not previously had tools to discover nor the opportunity to address in quite the same way.

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

A Buck By Any Other Name

buck

A Buck by any other name might be Hogan, Logan or Williams.  I think we have a case of surname schizophrenia.  We have four surnames involving 3 people.

Do you sometimes wonder why you or one of your relatives matches a whole group of people by a different surname, and none by the surname you expected them to match?

This 1888 Indian Census page for the Seneca on the Allegany Reservation in New York just might give you a clue as to why you’re not matching whom you think you should be matching..

Not matching who you expect to match is sometimes called a Nonpaternal Event (NPE) or I prefer the term undocumented adoption.  But this case doesn’t seem to be undocumented at all…it’s well documented….it’s just that we can’t understand it.

So let’s say this is your family and the husband, I presume is Augustus Buck.  So far, that looks normal.  But this is where normal ends.

Your name is Acsah.  If you’re married to Augustus Buck, your name would be Acsah Buck.  This is how all of the other families are recorded, so you would be too.  Except you have this little note that says either (Logan was) or Hogan was).  Is that a maiden name?  No one else’s maiden or other names are listed.  Is Acsah maybe not the wife of Augustus and the mother of Alfred noted below?  If that is the case, then why are they listed as Buck now?

And Alfred has his own set of problems.  He is noted as Alfred Buck, age 2. One would assume the child of Acsah and Augustus Buck, judging from the rest of the entries.  But Alfred had this note that says (was Williams.)  What does that mean?  It’s certainly not his maiden name.

Does that mean that Alfred isn’t a Buck at all?  Is Alfred even the son of Acsah?  Is Alfred really a Williams.  Was Acsah married to a Williams before Augustus?  That would seem to be pushing it given that she is only 18 and Alfred was born when she was 16.  Did she have time to be married earlier?

So, if Alfred’s descendants were to DNA test, would they match a Buck, a Williams, a Hogan or a Logan?  Or maybe none of the above if Acsah had Alfred before she married Augustus by someone not listed on the “was” list.  Maternal naming was a very common Native American occurrence and what is today considered to be illegitimacy was not viewed through the lens of colonial or Victorian America.

And just think, if you are Alfred’s great-grandson and you took the Yline DNA paternal line test, expecting to match a Buck, and you were instead matching a Williams, Hogan or Logan, and if you never saw this census page, you would have no clue as to potentially why.  Of course, if you aren’t matching a Buck or a Logan, Hogan or Williams, then all bets are off.  But at least, there is a clue here that something is not like the rest of the families recorded in the census.  It’s something to work with.

Of course, this makes me wonder how many more census entries warrant notes and of course never received them.  And of course, a legend to interpret the note would be nice too:)

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Surprise Y Matches – What do they Mean?

One of our blog followers, Tom, encountered the following situation, which, really isn’t so uncommon.

“I started up a Y-DNA surname project and recruited my only three living male 1st cousins who carry that name.

The first set of 67 results have recently been posted and within a day an exact match appeared with an individual who had only tested to 37 markers back in 2008.  Apparently the individual has had very few close matches and never a perfect match like my cousin’s.  But the individual has a different surname.

Is it possible to have an identical match as a random event?  How common are such occurrences?  What possible explanations could there be?”

Let’s look at Tom’s situation from different perspectives and see what we can find.

When I do DNA Reports for people, I still find people who don’t have any matches.  It’s not as unusual as people think.  In a way, it’s a blessing as compared to people who have so many matches that they can’t even begin to sort through them.  But to the person who doesn’t have any matches, it surely doesn’t seem like there’s a positive side to the situation.

First of all, remember that mutations can happen at any time in any generation….or not.  In the Estes line, Abraham Estes, one of two Estes immigrants to colonial America was born in 1647.  He had 8 sons.  We had DNA from the descendants of all 8 sons.  We reconstructed Abraham’s DNA using triangulation, so we know what his original genetic “signature” looked like.  One of those sons’ lines has 4 mutations in 8 generations, and one line has none.  The rest fall in the middle someplace.

I only mention this to illustrate that mutations are truly random events.  We use statistics to look at the “most likely” scenario, based on averages, but mutations are personal events and while they, as a whole, fall nicely into statistical models, individually, they happen when they happen.  You can see that the mutation rate can vary quite a bit, even within families.  Keep that in mind during the rest of this discussion.

Family Tree DNA gives us some tools to work with these kinds of situations.  The TIP calculator, available for every match by clicking on the little orange TIP button, tells us, statistically, how likely people are to match at which generational level.  This is called the time to the most recent common ancestor, or MRCA.  I did an earlier blog about this.

Comparing two exact 37 marker matches, below, we see that, statistically speaking, on the average, these two people are most likely to share a common ancestor about the second generation, meaning grandparents.  Again, word of caution, these are averages, which is why you have a range shown here.  DO NOT TAKE THEM LITERALLY.  I can’t tell you how many people obsess over these numbers and think that these numbers are telling them exactly when they share a common ancestor.  They don’t.

So let’s answer the questions that Tom asked.

Is it possible to have an identical match as a random event?

No, it’s not.  These men share a common ancestor at some point.  The question is, when and where.  However, it is possible to match on many markers, and then not on others.  I would suggest that these men upgrade to 111 markers and see how closely they match at that level.  I have seen at least one instance where 2 men matched at 37 and then had 5 or 6 mutations at the 67/111 marker level.  Unusual?  Yes.  Impossible?  No.

How common are such occurrences?

This isn’t as unusual as you would think.  I see this fairly often.  I always tell people to do four things.

First, upgrade the people you have to 111 markers.  If they continue to match at 111 markers, exactly, you probably have a very close match genealogically.

Second, find a second person to test from each line, as far back as possible.  In other words, if you’re testing the Abraham Estes line, you would want to find another son from Abraham to test to see if the DNA of the two sons match.  If they do match, then you know you have the lines proven back to 1647.  If not, then you know you have a non-paternal event (NPE) of some type, otherwise known as an undocumented adoption.  I call them undocumented adoptions because everyone knows what that means, and regardless of how it happened, it’s “undocumented” because we didn’t know about it.  In Tom’s case, he already has his 3 cousins, so his line is proven back to the common ancestor of those men.  Hopefully the person with the other surname can also find someone else from his line to test.

Third, enter the results into Sorenson at www.smgf.org and also into www.Ancestry.com for Y-line results to see if you come up with any other people who also match with that surname.  This is especially useful if you are having difficulty finding people to test.

Note: Neither SMGF nor Ancestry’s Y data base are available.

Fourth, look around the neighborhood – genealogically.  Are there reports of the two families in question being allied or intermarried in some location?  Were they neighbors in the same county?  In many cases, once you figure out that an undocumented adoption occurred – you can figure out in which generation through selective DNA testing, and often, which families were involved through DNA combined with historical and genealogical records.

In essence, to solve this type of puzzle, you need to become somewhat of a genealogical detective.

Tom’s last question was what kinds of situations could explain these results.

In some cases, especially where there are some mutations involved (meaning not exact matches), suggesting some time distance between common ancestors, matches between surnames occur because the families involved simply adopted different surnames.  When surnames were adopted varies dramatically by the location of the families and the circumstances involved.  For example, in the US, some Native American families were still using Native names in the 1880s.  Freed slaves adopted surnames upon obtaining their freedom in the late 1860s and early 1870s, and sometimes changed that surname at will.  In the Netherlands, some families didn’t take names until in 1811 when Napoleon mandated that they do so.  In England, some wealthy families had surnames by 1066, but peasants didn’t adopt surnames, for the most part, until in the 1200s and 1300s.  Jewish families in some parts of Europe didn’t adopt surnames until in the early 1800s.

Sometimes surname changes that look to us like undocumented adoptions occurred not at birth, but later in life.  Some people simply changed their names for a variety of reasons.

In one case, a man named John though he killed a man in Tennessee, ran off to the frontier which was at that time in Texas and changed his name, only to discover years later that not only had the man he shot not died, but that man had then married John’s wife he abandoned when he left.  Hmmm….karma at work.

One of the most common reasons for ‘undocumented adoptions’ is that a step-father raised the children and the kids simply used his name….forever.  So maybe John’s kids, above, took the surname of the man John shot.  Now this is getting interesting!!!  No wonder we have trouble figuring these things out retrospectively.

Another reason, of course, is that illegitimate children took the mother’s surname, but carry the father’s DNA signature.  In Native American cultures, matrilineal naming was very common, as is it in the African American culture, especially immediately after the end of slavery.  Children took whatever surname their mother adopted at that time.

Of course, the one thing we haven’t mentioned is the obvious….where someone was unfaithful.  Generally, that’s the first thing people think of…but it’s really not the most common reason.  But sometimes, indeed, it appears that Granny might have been a “loose woman.”  Don’t judge Granny too hardly though, because you really never know what happened in Granny’s life.  She could have had no choice in the matter, or her husband could have been abusive. We often see these conceptions during periods of war, especially the Civil War.  In one case, we know that a woman exchanged sexual favors for food for her children.  It’s really hard to be critical of that woman.

So the real answer for Tom is that there is no cut and dried answer, but lots of possibilities to explore.  You’re going to have to get out your Columbo tools and sleuth away….

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