Y DNA: Part 1 – Overview

This is Part 1 of a series about Y DNA and how to use it successfully for genealogy.

If you’re in need of a brief DNA testing overview, please read 4 Kinds of DNA for Genetic Genealogy.

Y DNA testing has so much to offer. In this overview article, I’m touching briefly on each of the major functions and features of Y DNA testing. Following articles in this series will focus on how to utilize each tool for genealogy and harvesting every snippet of information available.

If you have Y DNA results, you can sign on to your account at Family Tree DNA and follow along. Throughout these articles, we’ll step through every tab and function, how to use them, and what they mean to you.

What is Y DNA and Why Do I Care?

Y DNA is what makes males, well, male.

The 23rd pair of human chromosomes consists of an X and a Y chromosome.

Female children inherit an X from both parents.

Male children inherit an X chromosome from their mother, but a Y from their father.

Generally, the Y chromosome follows the male surname line, so Estes males pass their Estes Y chromosome to their sons.

When adoptions occur, of course the surname of record does not match the biological surname associated with the Y chromosome – which is exactly why male adoptees take Y DNA tests.

Inheritance Path

In the example below, you can see that the light blue Y chromosome is passed from father to son to son to son to the male child in the current generation.

Y overview inheritance path

Click to enlarge

The dark blue maternal great-grandfather in this example also passes his Y chromosome to his son, but it stops there since the next generation in this tree is a female.

The light blue son at the bottom inherits a Y chromosome from his father, from ancestors all the way up that light blue line – along with his surname. The daughter doesn’t receive a Y chromosome nor do any females.

If you’re a male, you can test your own Y DNA of course.

If you’re a female, like the daughter, above, you must find a male in the line you seek to test. In this case, the brother, father, grandfather, paternal uncles and so forth represent her father’s Y DNA.

If you want information from any of the Y chromosome lineages in this chart that you don’t personally carry, you must find a male descended directly patrilineally from that line to test. It’s generally fairly easy to identify those people, because they will also carry the relevant surname. There are several examples in the article, Concepts – Who to Test for Your Father’s DNA.

Every Y DNA line has its own unique story for genealogists to harvest – assuming we can find an appropriate candidate for testing or find someone who has already tested. We’ll talk about how to see if your line may have already tested in the Projects section later in this article.

Why Y DNA Works

Y DNA is inherited from the patrilineal line directly. Unlike autosomal DNA, there is no genetic contribution from any females.

This uniquely male inheritance path allows us to use Y DNA for matching to other males beginning with the first generation, the father, then reaching back many generations providing a way to view our ancestral heritage beyond the line-in-the-sand boundary of surnames.

In other words, because Y DNA is not mixed with any DNA from the mothers, it’s very nearly identical to our patrilineal ancestors’ Y DNA – meaning it matches that of the father, and grandfather, reaching back many generations.

Some people, especially new autosomal testers, believe that Y DNA is ONLY useful for deep ancestry and not for genealogy. That’s ENTIRELY mistaken. Y DNA is extremely important in confirming descent from known ancestors. In fact, without Y DNA, you can’t tell the difference with autosomal testing between a child born to a male and a child born to the female of a couple. I wrote about that hereNo one wants to spend years barking up the wrong tree.

Y DNA testing is also the single best way to push the Y DNA genealogy back further in time. It can and does identify the geographic source, overseas, of the DNA lineage, through matches to other testers as well as haplogroup matches. These are things autosomal DNA simply cannot accomplish.

In fact, Y DNA did exactly that for my own Speak(es) line, connecting us genetically to the Speak family from Downham, Lancashire, England which then facilitated discovering the actual baptism document of our immigrant ancestor. Finding our English geographic source had eluded researchers for decades. A year later, a group of 20+ descendants visited Downham and stood in that very church.

Speak Family at St Mary Whalley

There simply is no better success story.

Migration Path Identified

Not only can Y DNA confirm recent ancestors and find ones more distant, by tracing a series of mutations, we can track our ancestor over time beginning with Y Line Adam, born in Africa tens of thousands of years ago to that church in an ancestral country and then to where we are today.

Y overview migration path.png

Mutations Happen

If mutations never occurred, the Y DNA of all males would be identical and therefore not useful for us to use for genealogy or to peer back in time beyond the advent of surnames.

Mutations do occur, just not on any schedule. This means that it’s difficult to predict how long ago we shared a common ancestor with someone else based solely on Y DNA mutations – although some types of mutations are better predictors than others.

A mutation might occur between a male and his father, or there might be no mutations for hundreds or even, potentially, thousands of years – depending on the marker type.

For example, in the Estes DNA project, one group of men have no STR (short tandem repeat) mutations in 8 generations. Others have several in the same number of generations.

Part of the success of matching genealogically with Y DNA testing has to do with:

  • The type of markers tested
  • The number of markers tested – testing fewer marker locations results in matches that are much less specific and therefore less relevant.
  • The luck of whether anyone else from your line has tested

The best results are between men who have taken the Big Y-700 test which provides for the largest number of STR markers and all SNPs (single nucleotide polymorphisms) , both previously known and discovered individually during that person’s Big Y test result.

Let’s take a look at the two different kinds of Y DNA markers and their mutations.

Two Kinds of Mutations

Y DNA can be tested for two different kinds of mutations, STR (short tandem repeat) markers and SNPs (single nucleotide polymorphisms.)

All DNA is comprised of four different nucleotides, abbreviated by A, C, G and T.

  1. A=adenine
  2. C=cytosine
  3. G=guanine
  4. T=thymine

When mutations take place, they can take the form of three types of mutations:

  • A deletion occurs when a nucleotide, or multiple nucleotides, fail to copy during reproduction. Therefore, that location or locations are then blank, with no DNA at that location permanently.
  • A replacement occurs when a nucleotide is replaced or swapped out with a different nucleotide. For example, an A could be replaced with one of the other nucleotides, and so forth.
  • An insertion occurs when a nucleotide or a group of nucleotides is duplicated and inserted between existing nucleotides.

Let’s look at how this actually works.

Indel example 1

Here’s an example segment of DNA.

A deletion would occur if the leading A (or a series of nucleotides) were simply gone.

Indel example 3

A replacement would occur if the first A above were to change to T or G or C as in the example below:

Indel example 2

A replacement is a SNP mutation.

An insertion would be where DNA is inserted between existing nucleotide locations.

STR example

Note the extra red CTs that have been inserted. Specifically, 4 extra CTs, for a total of 5 sets of CT. This is the definition of a STR, a short tandem repeat mutation.

STR markers, known as short tandem repeats, accrue what are similar to copy machine errors. This occurs when a specific segment of Y DNA gets repeated several times in a row. In other words, the copy machine gets stuck.

STR Markers

We purchase STR Y DNA tests from Family Tree DNA grouped into panels that include a specific number of markers.

Y overview STR results

Example of 37 marker results – click to enlarge

These panels consist of the following number of marker locations:

  • 12 markers (now obsolete)
  • 25 markers (now obsolete)
  • 37 markers
  • 67 markers (replaced by 111)
  • 111 markers
  • 500 markers bundled as part of the now-obsolete Big Y-500
  • 700 markers bundled with the Big Y-700

The more markers purchased, the more data points to be compared, and the more relevant and convincing the results.

What Matches See

The STR matches and SNP matches look different on the tester’s results page.

Y overview matches

Click to enlarge

People whom you match on STR panels can see that you do match, if you’ve opted-in to matching, but they can’t see specific differences or mutations. They see the name you’ve entered for yourself, your earliest known ancestor and your match can send e-mail to you. Aside from that, they can’t see your results or mutations unless you’ve joined a public project.

Y overview project

Click to enlarge

Within projects, participant names cannot be listed publicly. In other words, your matches can’t tell that it’s you unless you tell them your kit number or they recognize your earliest known ancestor on the project page and you are the only person with that ancestor.

The Big Y-700 test tests all STR markers in addition to scanning the entire Y chromosome for all SNP (haplogroup defining) mutations. They have the STR matches page like everyone else, but they also have an additional Big Ypage.

People who have taken the Big Y test see a different view of matches on their Big Y matches tab. This is true for either the original Big Y, Big Y-500 which includes a minimum of 500 STR markers or the current Big Y-700 test which includes a minimum of 700 STR markers. (You can always upgrade to the Big Y-700 from earlier tests.)

Y overview Big Y.png

For SNP markers only, above, Big Y matches can see who they match and the SNPs they do and don’t match with that person in common.

For STR markers available only under the Big Y umbrella, meaning above 111 markers, results are displayed under the Y DNA Matches tab in the Big Y STR Differences column, below.

Y overview Big Y STRs

Click to enlarge

You can easily see that only one man on this match list has also taken the Big Y test, and he had 2 differences out of 440 markers. That’s in addition to 2 differences in the first 111 markers, for a total of 4 differences (mutations) in 551 markers.

Researching Without Testing

The great news is that even if you’ve just ordered your test and are waiting for results, you can research and join projects now.

For that matter, you can research using public projects without testing by going to the main Family Tree DNA webpage, scroll down and simply entering the surname of interest into the search box.

New dashboard surname search

You’ll be directed to surname projects where you can view ancestors and results of anonymized project members.

Give it a try to see what comes up for your surnames of interest.

Project Results

Projects at Family Tree DNA provide testers with access to volunteer administrators who help users with various types of information. Administrators also cluster users in projects that are meaningful to their research.

Most Y DNA testers immediately join their surname project.

Using the Estes surname project as an example, you can see that I’ve grouped the project members in ways I feel will be helpful to their genealogy.

Y overview Estes project.png

The Paternal Ancestor Names are particularly helpful to testers as well as people who are interested in testing in order to determine whether or not they are descended from a specific line.

It’s very useful to be able to discern if someone from your line has already tested – because it provides someone for you to match against, or not, as the case may be.

Y overview hap C project.png

The haplogroup C-P39 Y DNA project is shown above with the Paternal Ancestor Name as provided by testers that reflects Native American and First Nations ancestors.

Another important project feature is the project map function, allowing testers in a specific haplogroup (C-P39 below) to view the locations of the earliest known ancestors of other members of the same haplogroup – whether project members match each other or not. Your Native ancestors traveled with theirs and descended from a common ancestor. Cool, huh!

Y overview C map.png

What’s the story associated with the pin distribution of the C-P39 project, above? I wish we knew, and we may someday as research progresses. Whatever it is, it’s probably important genealogically.

Another type of project to join is a geographical or interest group project.

The Acadian AmerIndian Project welcomes descendants who have tested the Y, autosomal and/or mitochondrial DNA of the various Acadian families which includes French and English settlers along with First Nations indigenous ancestors.

Y overview Acadian.png

The map below shows the distribution of Y DNA members of the Acadian Amerindian project diaspora before and after Le Grand Dérangement” that scattered their descendants to the winds.

Y overview Acadian map.png

The pins on the Acadian Amerindian project map above are color coded by haplogroup.

Projects such as this facilitate genealogists discovering the haplogroup and related information about their direct line ancestor without personally testing.

Y overview Doucet.png

For example, if Germain Doucet born about 1641, part of the mustard-colored group above, is my ancestor, by viewing and/or joining this project, I can obtain this information about my ancestor. Project members can see more than casual browsers, because some testers only choose to display results to other project members and some projects are private, with results only displayed to project members. Many surname projects accept descendants who don’t carry the surname itself.

I obviously can’t personally test for Germain Doucet’s Y DNA myself, but thankfully, others who do descend patrilineally from Germain Doucet have been generous enough to test and share by joining this project.

Furthermore, I can contact the tester through the project administrator(s) and gain a great cousin with potentially LOTS of information.

Just think how useful Y DNA would be to genealogists if everyone tested!

Finding Projects to Join

I encourage all testers to join appropriate haplogroup projects. Often, more than one haplogroup project exists for each Y DNA letter, such as C or R. Generally, there are many subgroups for each core haplogroup and you may want to join more than one depending on your results.

I encourage testers to browse the selections and join other interest projects. For example, there are projects such as the Anabaptist Project which focuses on an endogamous religious sect, French-Swiss which is regional, or the American Indian project for people researching Native ancestry, in addition to relevant surname and haplogroup project(s). There are more than 10,000 total (well-organized) projects to choose from.

Your project selections may be a huge benefit to someone else as well as to your own research. Y DNA testing and matching is your best bet for jumping the pond and finding connections overseas.

How to Join Projects

Sign on to your personal page at Family Tree DNA and click on myProjects at the top, then on “Join A Project.”

Mitochondrial DNA join a project

Next, you’ll see a list of projects in which your surname appears. These may or may not be relevant for you.

Y overview project list

Click to enlarge

You can search by surname.

Y overview surname search.png

More importantly, you can browse in any number of sections.

Y-overview-project-categories.png

For Y DNA, I would suggest specifically surnames, of course, Y DNA haplogroups along with Y DNA Geographical Projects, and Dual Geographical Projects.

Y overview haplogroup alpha

Click to enlarge

When you find a project of interest, click to read the description written by the volunteer administrators to see if it’s a good fit for you, then click through to join.

Next Article in the Series

Of course, you’re probably wondering what all of those numbers in your results and shown in projects mean. The next article in a couple weeks will address the meaning of STR marker results.

Testing

If you haven’t yet Y DNA tested and you want to know what secrets your Y DNA holds, you can order your Y DNA test here.

_____________________________________________________________

Disclosure

I receive a small contribution when you click on some (but not all) 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

27 thoughts on “Y DNA: Part 1 – Overview

  1. Thanks for this article and for what is yet to come. I have many questions about what we can learn from the Big-Y 700 results. I got my results about a year ago and received my first match last weekend. We were already matches at the 111-marker range. My match and I, based on paper trail evidence, share a most recent common ancestor born in 1703. We share the same terminal SNP. A third person in our 111-marker group is upgrading. We believe he shares a MRCA with us who is one generation upstream. Should we expect him to have the same terminal SNP? In other words, are terminal SNPs likely to be more recent or more ancient? Our particular haplogroup is now listed on the block tree above a couple of sets of other haplogroups. One column has haplogroups with numbers that are just below and just above ours numerically. Are these people more closely related to us, or is there no real significance to the numbering system of SNP (Haplogroups)? In other words, the charts have lots of numbers that at this point don’t translate into meaning for me.I keep looking for a logic to the lettering and numbering in the tree that may not exist. I am hoping this will be some of what you cover in the next article.

    As always, I am grateful that you take the time to educate us with your blogs.Keep up the good work!

  2. I have ancestors (Barton) from Downham, Lancashire Co, England also. It is such a beautiful town, isn’t it? Now if I could just locate a male Barton from that line….

  3. I had a lot of hope (as an adoptee) when I paid for a Y DNA test four and a half years ago. I just wasn’t getting great matches on the big three DNA sites, but i figured that finding a surname for my father’s side would be a help in sorting out matches as they would continue to come in.

    I had less than half a dozen matches from that original test in late 2015, and I only pick up one every year and a half or two years. I haven’t had any since FTDNA’s involvement with news stories about using DNA to solve cold cases. None of the names even remotely match my French-Canadian autosomal matches.

    The only thing that will make Y DNA useful is if testing of that chromosome becomes a routine part of an under-$100 DNA test at most, if not all of the companies. At this point, I don’t see that happening.

    • I do wish all makes would Y DNA test. Be glad you don’t have hundreds of matches. That would be worse.

    • For French Canadians, results can vary a lot. Some families happen to have tested massively, for some others, no one at all have. Especially if they left little descendants in the US, genetic genealogy isn’t that popular in Canada yet, and even more so in French Canada. However, the amateur genealogist associations are starting to explain and promote genetic genealogy, especially mito and y matching to identify the DNA signature of as many settlers and First Nation ancestors as possible.

      I can only report my own experience, but here it goes anyway. I tested my father for his y-DNA in 2015 (Y37), and had only one match for three years, one who didn’t answer his emails because he was 6 feet under for 7 years. I knew we shared the same ancestor because he had the same name in the “last known ancestor” field. Last year, two matches appeared

      Beside him, I had a dozen of Y12 matches, I now have 28. But beside the three I mention above, all the rest are false positive.

      Anyway, don’t lose hope, the right matches may be coming in the 2020s.

    • I too am an adoptee, and was able to determine my French Canadian paternal line through autosomal triangulation, not Y-DNA matching. I was later able to match up a surname and upgrade another gentleman’s test from 12 STRs to 67 to confirm our mutual surname. So it is important to test at least to 67, if not 111. And join the the two projects that pertain, one the French Heritage and other the Quebec project. The administrators can help place your results and point you in the right direction.

      And great article Roberta !!

  4. Fantastic article Roberta – you are the best DNA blogger out there!
    You mentioned the BigY-500 is now “obsolete”. Does that mean that to go any further with my paternal genealogy I absolutely need to upgrade to BY700?

    If I don’t, then what are the benefits of going to BY700? Love to see this addressed in a future article.

    • I wrote about that when the Big Y-700 was first announced. It’s much more granular finding even more SNPs often. I was skeptical at first but have since upgraded several kits with good results.

    • I’m on my phone so searching is challenging, but search on the blog for Big Y- 700 and similar spellings.

  5. The Morrow folks did a Y-DNA study and found most of the information out there in the ether had most of us descending from somebody determined to be a bachelor uncle. Further study found two brothers that were the actual responsible parties and the studies were also able to distinguish who begat whom.

  6. Roberta,
    Thanks for all your blogs. Per the FTDNA help desk, the Big Y 700 uses the same algorithm for screening that the old Y-500 did. This is leading to strange “matches” and in my group, non-matches for men on the same terminal SNP (A5310). The screen for less than 30 non-matching variants is causing this. Are thee any FTDNA plans to change the screening?
    I think discussing this problem will fit into your current series on Y-DNA.
    Thanks.
    Larry

  7. One of the projects that accepts ‘other’ surnames is the Clan Gregor project, which my brother was surprisingly put into. I did not realize that the Mac / McGregors were banned for apx. 175 years in Scotland from using their surname (under penalty of death) and so our particular branch became McPhersons. I’m just trying now to find the link of exactly when that happened. I upgraded to the Big Y 500 just before they announced the Y700.

    On my maternal side I asked a 2nd cousin with the surname of Vickers to take the Y 37 test for me a few years ago. Our great grandfather Vickers was born illegitimately in Bolton, Lancashire to mother Vickers who was also illegitimate (as was her mother), so the surname came down through the women for 4 generations. His highest match at the Y37 level was a Munro, with a genetic distance of 3, followed by 4 Knowles. I’ve had no progress or additional information in the past 3 years.

    Initially, it was exciting to get a name of potential ancestor, but lately I find the lack of progress and / or communication from the groups rather disheartening.

  8. Great overview, Ms. Estes. My father was adopted at birth and never knew his birthparents. Y testing helped me identify his birth father’s family, and led to much more. I am a big proponent of BigY-700. It’s been very helpful not only for my direct paternal lineage, but also getting cousins on other lines to test has helped extend those much deeper into the past.

    Hope your series covers Yfull and its utility, especially with age estimation.

  9. Thank you, Roberta for yet another extremely helpful article. I have a question but first I need to share some background: I, along with two very distant male cousins, same surname, began our Y DNA Project in 2016 when we discovered we were Y37 matches (We did not know each other until this point). Out of curiosity, all three of us agreed to upgrade to Y67 which showed we still matched – the highest GD being 3. Over time three more Grays tested up to Y67 (one of them was my older 1C,1R) and we all shared the same I-M223 Haplogroup. I was the first to upgrade to Big Y-500 a couple of years ago, followed by those original two distant Gray cousins. It was determined by FTDNA our “shared Terminal SNP” was I-A18711. We all shared our BAM files with YFull (though we knew that was not mandatory) and learned more! YFull provides Age Estimation based on SNPs analysis which provides an estimated TMRCA for Big Y matches at the same haplogroup. YFull chose a different (equivalent) SNP to designate our Gray branch: I-A18713. As of today, 5 of 6 of the Grays in our original I-M223 group have upgraded to Big Y-700, and all 5 have shared BAM files with YFull. Our original goal was to discover how many distinct Gray sub-branches there were downstream of our shared “terminal SNP”, which turned out to be I-A18711 AND to learn the most refined time estimate to our shared common male ancestor. Based on the results of 4 Big Y-700 Grays (we are still waiting on Age Estimation for my cousin, the 5th Gray in our group), we all share a common ancestor who lived 200 – 250 ybp. My question to you is if the I-A18711/ I-A18713 SNP first formed around 100 AD (which I’ve been told), does that mean it took almost 2000 years for a new (Novel) SNP (aka Unnnamed Variant) to form with me and my cousin? YSEQ and YFull have determined my cousin and I share a previously unknown SNP downstream of I-A18713, which is I-A18721. Since I’ve heard the normal time between SNP mutations is 144 years, just how uncommon is this….IF, I’m reading it correctly?

    • The answer to this is “it depends.” I don’t know how many unnamed variants you have nor the specifics of the SNPs in question, nor who has what. So I can’t answer this in this type of venue. I apologize, but this is a consultation, not a quick question. As for age estimates, they are exactly that and the average number of years ranges from 80 to 150, depending on who you ask. The reality is that mutations happen when they happen, not on any schedule. Not only that, but the tree is being fleshed our further daily, with many more SNPs being added.

  10. Hi Roberta, this is very useful information. I thought if my brother didn’t have any matches at the 37-marker level that it would not be worthwhile to upgrade. But I think I may have misunderstood. Does testing more markers make it more likely we will find matches?

    • If the other person tested at higher levels and your mismatching markers are at lower levels. SNP testing with the Big Y is matching using entirely different mutations that generally match further back in time.

      • I have no idea if anyone on this paternal line has tested, so I’m still not clear if it would be worthwhile to spend money for an upgrade. There are no DNA projects for the surname, either.

        • I don’t know. It’s a gamble, that’s for sure. Have you worked with autosomal? What is your goal?

          • Using my autosomal, I’ve traced my paternal line back to the immigrant ancestor (Prussian, arrived c. 1840) through two NPEs (my biological grandfather and his biological father). I suppose I would like to connect with the German side of the family. I’ve certainly got no shortage of cousins in the US on this line! My brother’s haplogroup apparently hails from North Africa (Arab), which strikes me odd. I’d like to figure that out, too.

  11. Does the Y chromosome contain anything but lineage? That is, are the any traits that are also based in thee Y? Your autosomes blur with time as they intermix, but since the Y never changes (much) are there any traits like blue eyes, height, intelligence, or eyelids, for instance, that carry on forever?

    • Good question, but none discovered yet. They would have to be traits for males only and those physical traits are well known.

Leave a Reply