Introducing The DNA Match Review Page 23&Me

 

 

 

If you’ve taken a MyHeritage DNA test or uploaded your DNA data to MyHeritage, then you will have received a list of your DNA Matches. The list shows people whose DNA matches yours, the percentage of DNA you share, and your possible relationship. DNA results can imply several possible relationships between you and a DNA Match, such as 3rd – 4th cousin, but now you’d like to understand how you are related to the match. Where do you go from here?

We’ve just released a new feature — the DNA Match Review page — to help you answer that question. The new page offers a plethora of detailed information about each of your DNA Matches. Your DNA Match details are now consolidated into one place with different sections that will help you discover how the match may be related to you. This can open the door to new connections and discoveries to advance your family history research.

Below we describe the Match Review page comprehensively. We recommend reading this in depth because it includes important information about exciting new features, some of which are available only on MyHeritage.

Accessing the Review Match Page

On the DNA Matches list, click the “Review match” button in the bottom right corner of any of your matches, as shown below.

Accessing the new DNA Match Review page (click to zoom)

If you need a reminder on how to take full advantage of the features of the DNA Matches list, such as the powerful filters, see our previous blog post.

The DNA Match Review page shows all relevant data about the match, combining information from DNA and family trees. It is displayed in an easy to use side-by-side comparison. Here’s how the page looks, and below this image, we’ll breakdown these sections for you.

DNA Match Review page (click to zoom)

The Match Review page includes the following sections:

Smart Matches

Smart Matching™ is a MyHeritage technology that matches people in your family tree with people in other family trees that users all over the world have created on MyHeritage.

The presence of Smart Matches increases the confidence of DNA Matches — If you share a percentage of DNA with someone, and your trees also have Smart Matches, it increases the likelihood that you are related and makes it easier for you to understand how you are related. You can contact the match and learn from each other about your shared common relatives.

Smart Matches™ section (click to zoom)

When a DNA Match is correct, i.e. is not a false positive, it means that you and the match have a common ancestor, from which both of you inherited some DNA. The DNA Match is found by MyHeritage if both of you inherited the same segments of DNA from that ancestor. If you have Smart Matches with the family tree of your DNA Match, they may include your common ancestor, or at the least help point you in the direction of that ancestor.

We’ve found that in many cases, when DNA brings two relatives together, neither of them knows about the other and it is rare for their family trees to overlap. That’s why in most of the DNA Matches you’ll review, there won’t be a Smart Matches section. When it does exist, you should rejoice as you will likely be able to find out exactly how you are related.

Ancestral Surnames

Ancestral surnames are the surnames of your direct ancestors (or the surnames of the direct ancestors of your DNA Match), which are retrieved from your family trees on MyHeritage. In DNA context, ancestral surnames are very important because every person is an aggregation of DNA segments from his or her ancestors. Therefore, the ancestral surnames indicate the families from which people have inherited their DNA, assuming their family trees are correct and faithfully depict their biological roots.

On MyHeritage, most DNA customers have family trees, which is very fortunate as it allows us to retrieve ancestral surnames and compare them for most DNA Matches.

If you and a DNA Match have shared ancestral surnames, this section will show the ancestral surnames you have in common – those surnames that appear in both your family trees, going back 10 generations.

Shared Ancestral Surnames section (click to zoom)

This section can be extremely useful in determining which common ancestor you and the match share, helping you identify a potential common ancestor. Be careful though if the ancestral surname is very common, like Miller or Smith, because that is very likely not the same family. However, if the ancestral surname that you and your match share is extremely rare, such as Dankworth or Culpepper, you’re certainly on the cusp of understanding how you are related.

Click on the button “View all ancestral surnames” in the bottom right corner of this section, to see a new window with an alphabetized list of all the ancestral surnames in both your family tree and your DNA Match’s family tree. In this new window, you will be able to scroll through all ancestral surnames, and the surnames you share will be highlighted in purple.

Viewing a list of all ancestral surnames (click to zoom)

Don’t have any shared ancestral surnames? Then we will still show you the ancestral surnames in both your family tree and the match’s family tree. This could be helpful if one of their surnames is similar to yours (though with a different spelling), or perhaps a surname will ring a bell and remind you of a relative not yet listed in your tree.

For example, you may have ancestors with the last name MacQuoid but you don’t know exactly where they connect in your tree, so you’ve never added them. After reviewing a DNA Match’s ancestral surnames, you might notice they have the surname MacQuoid in their tree, and you can begin putting together the puzzle of how you are related.

Next to each ancestral surname, we also list associated countries where vital events (birth, marriage, death, burial, etc.) occurred for the ancestors with that surname. This will be useful when trying to understand the possible relationship you might have with your DNA Match. For example, if you both share an ancestral surname from the same country, it can increase the strength of the match. You might not get excited about sharing the ancestral surname of Levine, but if both of you have Levine from Hungary, that could be more interesting. In addition, if you don’t have a shared surname, but you do share ancestors from the same countries, it could mean that you both share roots in the same region.

The list of ancestral surnames and their countries, even beyond the context of DNA, is very handy. We recommend for genealogists to copy the list of ancestral surnames and use it when they email other genealogists since the list serves as a convenient way of expressing one’s research interests. Some genealogists even use the ancestral surnames list as their email signature!

Shared DNA Matches

Shared DNA Matches are people who share DNA with both you and your DNA Match, meaning both of you have the same person in your list of DNA Matches. This is another way of increasing the confidence in your DNA Match and helps you learn which side of the family your DNA Match is on.

MyHeritage has a unique way of showing Shared DNA Matches. Unlike other testing services, we display – in one chart – how both you and your DNA Match are genetically related to the same person.

Shared DNA Matches section (click to zoom)

In this section, the name of each Shared DNA Match is clickable and allows you to go to the DNA Match Review page for that specific match.

If you and your DNA Match have many Shared DNA Matches, you can click on the button “Show more DNA Matches” in the bottom right corner of the section to review all of your Shared DNA Matches.

The Shared DNA Matches page helps you cluster our DNA Matches. Each cluster may indicate matches having the same common ancestor (sometimes there may be several different ancestors). You can collaborate with your matches to try to determine who that common ancestor is.

In time, you will learn to appreciate the power of the Shared DNA Matches page. For example, if you review a match and spot your paternal uncle in the list of shared matches, that is a good indication that the match is paternal for you. Testing more of your relatives will help you get more value from the Shared DNA Matches page, as it will help you determine the path to the common ancestor for many of your matches.

Pedigree Charts

Pedigree Charts show the main individual and their direct line of ancestors, i.e., parents, grandparents, great-grandparents, etc. These charts are especially helpful when looking for common ancestors and for identifying common names, which can provide an idea of how you are related.

The Pedigree Chart section shows your match’s direct ancestors in one tab and shows your own pedigree chart in an adjacent tab. Viewing the Pedigree Chart of your match’s family tree in this way makes it easy to check where your trees may overlap, and see if you spot anything familiar.

Pedigree Charts section (click to zoom)

The Pedigree Chart is condensed to show a lot of information in little space.
To view the full tree, click “View full tree” at the bottom right corner.

Women appear in the Pedigree Chart with their maiden names. To see more information about any person, hover the mouse over the card. A callout will open, as shown below, adding more information, such as birthplace and death place. It will also provide you with handy links to view the family tree around that person, visit the profile or research that person in MyHeritage’s huge collection of 8.1 billion historical records.

Person callout in Pedigree Chart (click to zoom)

If you are using MyHeritage DNA and still don’t have a family tree on MyHeritage, please build one now. It is very helpful for making sense of your DNA Matches and will also be helpful for other users whose DNA matches your own.

Whenever viewing the family tree of another person, living ancestors will be privatized.

Shared Ethnicities

For every DNA test taken on MyHeritage, or uploaded to MyHeritage, we calculate an Ethnicity Estimate, which finds ethnic origins. MyHeritage offers a breakdown of 42 different ethnic regions – more than any other major commercial DNA testing company.

The Shared Ethnicities section compares the Ethnicity Estimate of your DNA Match to your own to find similarities. This interesting section is visual and only displayed on MyHeritage this way. You will see the exact percentage break down of your ethnicities side-by-side with your DNA Match’s ethnicities, and those you share will be highlighted in purple.

Shared Ethnicities section (click to zoom)

The Shared Ethnicities section can be useful for indicating the regions where you and your DNA Match may have common ancestral origins. Be aware though that you might share an ethnicity with a DNA Match, but not because you inherited it from the common ancestor that you share. Each of you may have gotten that ethnicity from other ancestors that you do not share.

You can use a toggle on the top right corner to show only shared ethnicities or all ethnicities. Click any ethnicity for more information about it.

Next steps

We’re not done with the Review Match page yet! Additional features are on the way to make the Review Match page even more informative and useful, such as the commonly requested Chromosome Browser, so keep an eye out for them.

Cost

For MyHeritage DNA customers, some sections on the Review Match page require a family site subscription to view them in their entirety. Users with a Premium, Premium Plus, or Complete subscription will have full access to all sections on the Review Match page, while Basic users will have a partial view of some sections.

Note: Some features listed above may not be shown for each of your DNA Matches if not relevant for that match. For example, if you match with someone who doesn’t have a family tree, then for that match you will not see tree components such as the Pedigree Chart, ancestral surnames and Smart Matches.

Conclusion

Take advantage of our new DNA Match Review page and delve into your DNA Matches. Matches previously overlooked can now be explored for new possible family connections. Instead of piecing together the puzzle yourself from scratch, these new tools will help you better understand how you are related to your matches.

Not in on the DNA action yet? Order your MyHeritage DNA kit today or, if you’ve already had your DNA tested by another company, upload your DNA data to MyHeritage and receive a comprehensive DNA Ethnicity Analysis and DNA Matching for free.

Enjoy!

MyHeritage Team

Leave a comment

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  • Jason Lee

    August 22, 2017

    Where’s the chromosome browser?

    • Esther

      August 23, 2017

      Hi Jason,

      We hope to release a chromosome browser in the near future. Stay tuned!

      Best,
      Esther / MyHeritage Team

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Journey From Igboland to South Carolina

 

 

 Resource for further information: “The Voyage of the Slave Ship Hare”

I read This article four times to get a feeling for the author and the story. I realized I had transcended home to Igbo land.

Resource: Access August 9, 2017 – https://www.dnatestedafricans.org/single-post/2017/06/18/The-Invisible-Artifact-Something-Amazing-Happened

The Invisible Artifact ~ A Journey From Igboland to South Carolina

April 16, 2017

|

AdaaEze Naja Chinyere Njoku

A Dibia (native healer) in Igboland was awakened from a very disturbing dream. The gods were giving him a message. He went to the Eze (king) and informed him. The Eze told him to go and do what he was directed. He returned to the shrine after gathering wood from the sacred Iroko tree. He personally carved a mysterious artifact, creating a secret compartment at the bottom where he placed inside, a kola nut, alligator pepper , and a message.

 


Meanwhile, the Eze summonsed the town crier to have every elder male and elder female of each family to meet him at his palace immediately. They each arrived wondering why they were assembled at such a later hour. The Dibia returned with the artifact and explained that the gods told him of an impending danger.


He said that a tomb will float on the great water, bringing a choking white fog.
The fog would engulf many of the village people but some will survive. He advised
that when this horrible white smoke came, to run to a place near the evil forest
where they would be invisible to the naked eye. A great fear came over the
villagers because no one went near the evil forest unless they were cast out of the
village. It was an abomination.

The elders all began to speak at the same time.


The clanking sound of the Dibia’s staff striking the ground, caused a silence to
roll across the tongues of each person there. His eyes turned a hazy white as he
went into a trance. He said, “Out of this abomination, our people will return”. He
directed each elder to come to the artifact. He recited an incantation and told
each elder to touch a different area of it. When they touched it, that area displayed
a mystical glowing symbol that was not carved into the artifact.

It sealed their DNA into the symbols.

The Dibia explained that the mystical symbols would only glow when a descendant of the elder that touched it was near.


When the last elder touched the artifact, a second seal was placed upon it and another artifact, an exact duplicate appeared out of a puff of red smoke. They were all amazed. He kept the second artifact with him. It could only be passed from Dibia to his successor, until the time of reckoning.


The Dibia called the strongest man in the group. His name was Obinna (Obi). He was noticeable because of the bright spiritual glow about him that only he could see.
 

The guards were given instructions to hold him, regardless to what happened
next. They did. The Dibia placed a green herb in his mouth and pushed the
artifact into his chest. It started to burn his skin as he screamed in uncontrollable
pain. His skin divided and the artifact went inside of him. Then the pain was
gone as if nothing happened. Eze assigned him warriors to guard him day and
night. They were all sworn to secrecy to NEVER reveal what took place that night.

 

About 7 years later, the dreaded tomb came floating on the great water. The white
fog rolled all around it. Many were taken away in the fog while some made it
safely to the meeting place. A mother screamed in the darkness. She was unable
to find her son Obi. He was the one that the Dibia chose to hold the sacred
artifact inside of him.


 

Three Months on the Great Wata
 


The white fog took him and many others to a foreign land. Obinna (Obi) and those that
were with him in that dreadful tomb were placed on a block and sold into slavery.
Obi lived to be 97 years old. He had many children and grandchildren. They called him Papa Obi. They all remembered the stories he told of how he was brought to this place when the white fog came to his homeland. He told them of how he found that some of his age mates decided that they would rather drown themselves than to be enslaved. He even tried himself but the water would not take him. The artifact inside of him caused the water to push him back to the
surface and back away.


His children loved his stories and decided to research this place that seemed almost mythical. They found that it is now called Nigeria. Some call it Naija.  He always said he could still hear his mother’s voice from back home, guiding him, even until the day he died. His body was laid to rest in a beautiful wooden coffin at the foot of a huge tree, in a place now called South Carolina. His tombstone read ” Here lies Obinna, also known as Papa Obi, born 1724 in Nigeria; died 1821 in SC”.

Each year this amazing tree grows closer to its roots and has several knots and bends in it. There is no other tree like it in the whole land.  Some folks call it an angel oak tree.  Others call it a Spirit tree.  There has always been something different about that tree.

 


275 years later, in Nigeria….2016

A Dibia is awakened from a dream. He performed an incantation and retrieved
the artifact. He took it to the Eze and explained its history. The elders of each
family were called to witness the extraction of the message and the Kola nut. The
message read ““Out of this Obama Nation, our people will return. Obi is Ibo, SC”.
It was a peculiar message.


Several scholars, at the University, were called to try to decipher its meaning. It
was baffling. A Nigerian private investigator, named Emeka, was also contacted.
He was preferred because he was aware of the modern day technology as well as
the ancient customs of his people.


When Emeka was taken to see the artifact, one of the symbols glowed. It was a
tree with the letters SC at the bottom of the tree. He found that Obinna and he
shared the same ancestor. They were family! This investigation became a
personal journey. His family was taken by the white fog. Many questions
consumed him. Where are they now? What happened to them? Emeka had to
know.

His Journey to South Carolina began …

Read more by clicking on the link: https://www.dnatestedafricans.org/single-post/2017/06/18/The-Invisible-Artifact-Something-Amazing-Happened
 

Gedmatch Autosomal DNA Segment Analyzer (ADSA)

Autosomal DNA Segment Analyzer (ADSA)
GEDMATCH Quick Start Guide

ICW means In-Common-With were ever used

To use GEDMATCH with ADSA you must be a Tier 1 GEDMATCH member. That means you must have, at some time, donated at least $10 to GEDMATCH. The GEDMATCH upload process for DNAgedcom.com depends on two Tier 1 tools: Matching Segment Search and Triangulation which you cannot access unless you are a Tier 1 member. And, of course, you must have loaded your raw data to GEDMATCH previously so that it has been tokenized and batch processing is completed.

Some other things to be aware of:

  • Certain fields that are available for Family Tree DNA kits are not presently available for GEDMATCH. These include:

    Match Date

    Predicted Relationship

    Known Relationship

    Relationship Range

    Haplogroups

    Surnames

    Total Shared cM

    Longest Block cM

    So, this means that using these for sorting, selection, highlighting or display purposes may not have the results you wanted because these fields are empty in a GEDMATCH kit.

  • To manage processing load on GEDMATCH’s servers, only the In-Common-With (ICW) indicators for your top 400 matches are provided by GEDMATCH, so you will only have ICW bricks in the ADSA report for your longer segments. You can manually determine ICWs for other matches by doing a one-to-many report for one of your matches and comparing their list of matches to yours.

  • Generally, there are a lot more segments in a GEDMATCH ADSA report than for Family Tree DNA. This tends to slow down the responsiveness of your browser when viewing the ADSA report. You may wish to increase the minimum segment size in ADSA to 10 cM(Centimorgans)

  • The GEDMATCH tools that are used to gather the data for DNAgedcom exclude very close relatives (eg. siblings, parents, children) to improve processing performance, so you will not see them as matches on your ADSA report for GEDMATCH kits.

  • The X chromosome matches are not presently included in GEDMATCH kits.

To get started, follow these steps.

  1. If you haven’t already done so, go to www.DNAgedcom.com and click on “Register”:

  2. Register for a free account at DNAgedcom.com:

  3. Logon to DNAgedcom.com with your new username and password:

  4. Prepare to upload your GEDMATCH data to DNAgedcom.com:

    You will see a screen with a large, square text input box. Do not enter anything here yet.

  5. Leaving the window above open, create a new browser window or tab and go to the www.gedmatch.com and

    logon

    . Click on “Matching Segment Search” in the Tier 1 tools menu near the bottom of the screen:

  6. Enter your kit number and click “No” on the graphic bar (very important!) and click “Submit”:

  7. Now wait for the report to finish – it will probably take a few minutes. When it is complete it will look something like this:

    Select everything on the screen and copy it to the clipboard. In

    Windows

    you can do this using

    ctrl-a

    followed by ctrl-c. On a

    Mac

    you can use command-a and command-c. You may have to wait a little while for the copy to complete. There is a lot of data there to copy. (If you don’t wait long enough, when you paste the information into DNAgedcom you won’t get what you copied. You may see a

    hour-glass

    or spinning beach-ball while the copying is going on.

    Usually

    the copy process doesn’t take more than a minute or two.)

  8. Go to the browser window you have open to DNAgedcom.com. Click

    in

    the square box and paste what you copied into it. On

    Windows

    you can use Ctrl-v or you can use command-v on a Mac.You should see a portion of what you copied like this:

    Click the “Load” button. The load should complete in a few seconds.

  9. Click the Clear button to erase the text-input box again and return to your GEDMATCH browser window. Return to the main GEDMATCH menu again.

  10. Now click on the Triangulation tool.

  11. Enter your GEDMATCH kit number and select the middle radio button (very important!) and click on the “Triangulate” button:

  12. Wait for the report to complete. The Triangulation report may take longer than the Matching Segment Report depending on how many In-Common-With matches you have and the current load on GEDMATCH’s servers. When it finishes there will be 4 rows of asterisks on the screen and the screen will look something like this:

    Once again, select the entire page (ctrl-a or command-a) and copy it to the clipboard (ctrl-c or command-c). Wait for the copy to complete. Then switch back to your DNAgedcom browser window.

  13. Make sure the text-input box in DNAgedcom is empty (use the Clear button if you need to) and then paste the Triangulation report into the box with ctrl-v or command-v. Then click on the Load button.

  14. When the Load process completes the screen will refresh. You can now go to ADSA by selecting the Autosomal Tools menu and the Autosomal DNA Segment Analyzer option on that menu. Or you can go to this link: http://www.dnagedcom.com/adsa. You will see a screen like this:

  15. Select your kit from the drop-down menu. GEDMATCH kits will start with a letter (A=Ancestry, F=FTDNA, M=23andMe etc.):

  16. Click GET REPORT

  17. If you have Ashkenazi ancestry or are part of an endogamous (interrelated) group you may not be able to generate a report with the default input parameters. Please consult the Tips for People with Ashkenazi Ancestry page before clicking GET REPORT.

For more information about this process, how to interpret your results, or troubleshooting, read the full ADSA manual.

Centimorgans in Genetic Geealogy

Reprinted from the International Society of Genetic Genealogy August 2, 2017. No adjustment was made to this article and is the ISOGG position.

 

In genetic genealogy, a centiMorgan (cM) or map unit (m.u.) is a unit of recombinant frequency which is used to measure genetic distance. It is often used to imply distance along a chromosome, and takes into account how often recombination occurs in a region. A region with few cMs undergoes relatively less recombination. The number of base pairs to which it corresponds varies widely across the genome (different regions of a chromosome have different propensities towards crossover). One centiMorgan corresponds to about 1 million base pairs in humans on average. The centiMorgan is equal to a 1% chance that a marker at one genetic locus on a chromosome will be separated from a marker at a second locus due to crossing over in a single generation.

The genetic genealogy testing companies 23andMeAncestryDNAFamily Tree DNA and MyHeritage DNA use centiMorgans to denote the size of matching DNA segments in autosomal DNA tests. Segments which share a large number of centiMorgans in common are more likely to be of significance and to indicate a common ancestor within a genealogical timeframe.

The centiMorgan was named in honor of geneticist Thomas Hunt Morgan by his student Alfred Henry Sturtevant. Note that the parent unit of the centiMorgan, the Morgan, is rarely used today.

23andMe and Family Tree DNA both use HapMap to infer their centiMorgans.

centiMorgans vs megabases

CentiMorgans are interpolated numbers that take into consideration each area of a chromosome and its propensity to recombine. This means if two cousins share 40 cM on chromosome 1, and two different cousins share 40 cM on chromosome 5, they both can be predicted to share a certain degree of relationship statistically. Megabases vary slightly in different locations so that in the same scenario, if both sets shared 40 Mb pairs, it would be more difficult to ensure they are of a similar degree of relation without further accounting for location, chromosome and other factors.[1]

Ann Turner provides a useful explanation: “I think of the cM as being a unit of ‘effective’ distance. As an analogy, a mile is a fixed quantity (5280 feet), and so are megabases. But the probability that a person can walk a mile in 20 minutes is more fluid. If the terrain is very rough, the “effective” distance of a literal mile might be more like two miles if you’re trying to arrive at a certain time. We’re more interested in the probability that a segment will be passed on intact than the size of the segment in Mb”.[2]

As the cM is an empirical measure, based on recombination events in a particular dataset of parents and offspring, it can vary somewhat from study to study. This set of maps for each chromosome shows that the general shape of the centiMorgan vs megabase curve is similar for two datasets, but the absolute values are not quite the same:

http://web.archive.org/web/20070113005025/http://compgen.rutgers.edu/maps/compare.pdf

cm values per chromosome

The following table compares cM values per chromosome at Family Tree DNAGEDmatch, and 23andMeAncestryDNA uses 3475 as the total cM according to the help screen for confidence level in a DNA match. This presumably excludes the X chromosome.

CM chromosome FTDNA&GEDMatch&23andMe.jpg

Probability of crossover

The following chart shows the estimated probability that a segment will be affected by a crossover. The chart does not take into account some variables such as inversions and different recombination rates for males and females.

Crossover probability centiMorgans.png

Converting centiMorgans into percentages

In order to get an approximate percentage of shared DNA from a Family Tree DNA Family Finder test, take all of the segments above 5 cM, add them together and then divide by 68.

The way the calculation works is that your total genome in cMs with the Family Finder test is 6770 cM. A half-identical match (such as a parent/child) is 3385 cM. This number has to be doubled to represent both the maternal and paternal sides giving a total of 6770 cM. Matt Dexter explains: “The reason the number is not 6770 or 6800, but rather 68, is that it saves an additional step doing the math to convert an answer to percent. For example, 3385 / 6770 = .5 then as a second step, .5 times 100 = 50%. Using 68 to start with saves the added math step. So (3385 / 6800) * 100 is the same thing as 3385 / 68, which results in = 50%.”[3]

Human reference genome

The centiMorgan totals per chromosome are based on the Human Reference Genome. 23andMe and Ancestry DNA use Build 37. Family Tree DNA use Build 37 for matching but Build 36 for segment boundaries in the Chromosome Browser. Raw data files are provided in both formats. Build 37 filled in quite a few gaps, and the number of base pairs in each of the chromosomes was longer in Build 37 as compared to Build 36. Consequently the cM totals per chromosome are lower for Family Finder than they are for 23andMe. GedMatch use Build 36, and convert AncestryDNA and 23andMe data from Build 37 to Build 36 for backward compatibility.

The latest version of the Human Reference Genome, Build 38, was released in December 2013. However, none of the companies have as yet adopted Build 38 and there is a “gentleman’s agreement” in place to stick with Build 37 for the present time.

Further reading

Resources

DNA Triangulation, What?

Triangulation is a term derived from surveying to describe a method of determining the Y-STR or mitochondrial DNA ancestral haplotype using two or more known data points. The term “Genetic Triangulation” was coined by genetic genealogist Bill Hurst in 2004 Triangulate

Here is a 3-step process for Triangulation: Collect, Arrange, Compare/Group.

  1. Collect all the Match-segments you can. I recommend testing at all three companies (23andMe, FTDNA, and AncestryDNA), and using GEDmatch. But, wherever you test, get all of your segments into a spreadsheet. If you are using more than one company, you need to download, and then arrange, the data in the same format as your spreadsheet. Downloading/arranging is best when starting a new spreadsheet. Downloading avoids typing errors, but direct typing is sometimes easier for updates. I recommend deleting all segments under 7cM – most of them will be IBC/IBS (false segments) anyway, and even the ones which may be IBD are very difficult to confirm as such. You are much better off doing as much Triangulation as you can with segments over 7cM (or use a 10cM threshold if you wish), and then adding smaller segments back in later, if you want to analyze them. NB: Some of your closer Matches will share multiple segments with you – each segment must be entered as a separate row in your spreadsheet. The minimum requirement for a Triangulation with a spreadsheet includes columns for MatchName, Chromosome, SegmentStartLocation, SengmentEndLocation, cMs and TG. Most of us also have columns for SNPs, company, testee, TG, and any other information of interest to you. Perhaps I need a separate blog post about spreadsheets… ;>j
  1. Arrange the segments by sorting the entire spreadsheet (Cntr-A) by Chromosome and Segment StartLocation. This is one sort with two levels – the Chromosome column is the first level. This puts all of your segments in order – from the first one on Chromosome 1 to the last one on Chromosome 23 (for sorting purposes I recommend changing Chromosome X to 23 or 23X so it will sort after 22). This serves the purpose of putting overlapping segments close to each other in the spreadsheet where they are easy to compare.
  1. Compare/Group overlapping segments. All of these segments are shared segments with you. So with segments that overlap each other, you want to know if they match each other at this location. If so this is Triangulation. This comparison is done a little differently at each company, but the goal is the same: two segments either match each other, or they don’t (or there isn’t enough overlapping segment information to determine a match). All the Matches who match each other will form a Triangulated Group, on one chromosome – call this TG A (or any other name you want). Go through the same process with the segments who didn’t match TG A. They will often match each other and will form a second, overlapping TG, on the other chromosome – call this TG B. [Remember you have two of each numbered chromosome.] So to review, and put it all a different way: All of your segments (every row of your spreadsheet) will go into one of 4 categories:
  • – TG A [the first one with segments which match each other]
  • – TG B [the other, overlapping, one with segments which match each other]
  • – IBC/IBS [the segments don’t match either TG A or TG B]
  • – Undetermined [there are not enough segments to form both TG A and TG B                            and/or there isn’t enough overlapping data to determine a match.]
  • NB: None of the segments in TG A should match any of the segments in TG B.
  1. At GEDmatch – the comparisons are easy. Just compare two kit numbers using the one-to-one utility to see if they match each other on the appropriate segment. The ones that do are Triangulated. You may also use the Tier1 Triangulation utility or the Segment utility. I prefer using the one-to-one utility and Chrome.
  1. At 23andMe you have several different utilities:
  • – Family Inheritance: Advanced lets you compare up to 5 Matches at a time. You may also request a spreadsheet of all your shared segments; sort that by chromosome and SegmentStart, and check to see if two of your Matches match each other. The ones that do are Triangulated.
  • – Countries of Ancestry: Sort a Match’s spreadsheet by chromosome and SegmentStart, search for your own name, and highlight the overlapping segments. The Matches on this highlighted list who are also on overlapping segments in your spreadsheet are Triangulated (the CoA spreadsheet confirms the match between two of your Matches)
  1. At FTDNA it’s a little trickier, because they don’t have a utility to compare two of your Matches. So the most positive method is to contact the Matches and ask them to confirm if they match your overlapping Matches, or not. The ones that do are Triangulated. An almost-as-good alternative is to use the InCommonWith utility. Look for the 2-squigley-arrows icon next to a Match’s name, click that, and select In Common With to get a list of your Matches who also match the Match you started with. Compare that list of Matches with the list of list of Matches with overlapping segments in your spreadsheet. Matches on both lists are considered to be Triangulated. Although this is not a foolproof method, it works most of the time. And if you find three or four ICW Matches in the same TG, the odds are much closer to 100%. Remember, every segment in your spreadsheet must go in one TG or the other, or be IBC/IBS, or be undetermined. If a particular Match, in one TG, is critical to your analysis, then try hard to confirm the Triangulation by contacting the Matches.
  1. AncestryDNA has no DNA analysis utilities. You need to convince your Matches to upload their raw data to GEDmatch (for free) or FTDNA (for a fee), and see the paragraphs above.

Comments to improve this blog post are welcomed.

Genetic Genealogy For Beginners – Discovery your Family History Through DNA 101

 

 

 

This course as the first one “Genetic Genealogy For Beginners” is an expansion and goes a little more deeper into the DNA with some additional learning tools. In these lessons rather than chapter we will use Genetic Genealogy, Molecular Genealogy (the field of biology that studies the structure and function at the molecular level and thus employs methods of both molecular biology and genetics. The study of chromosomes and genes expression of an organism.) Sounds intimidating but it will be broken into manageable understandable lessons. There is a test after each lessons to help you gain a solid background before moving to Intermediate and Advance Genetic Genealogy. This will be a four week course and starts May 1 – May 26 2017.

mark you calendar for this course.

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