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Using Ancestry DNA hints to prove and disprove ancestors

Jul9

With over 4 million DNA tests [as of 11 aug 2018 – 10 million], the Ancestry database has reached a tipping point where any tester with American ancestry will get some good cousin matches. How do these help prove an ancestral line? Well when your DNA matches multiple people descended from the same ancestral line, you can have some confidence in that part of your tree. Conversely, if you have no matches on a line, there may be a problem.

On your DNA home page, the center panel summarizes your match count. It shows the number of predicted 4th cousins or closer as well as the number of starred and green leaf ancestors. You can add stars to matches for whatever reason you wish. Only you and anyone you share your DNA results with can see them. Ancestry will indicate each DNA match that also has a tree match with you by using a green leaf.

Ancestry DNA Home Page Center Panels (words in red are mine)

Notice the big difference in the number of cousins between those with 19th and 20th century immigrant ancestors like my family and those with deep American ancestry. Also foreigners like my Norwegian cousin will have very few, while Jewish testers will have incredibly high numbers due to endogamy.

DNA Matches Page

Click on the green View All DNA Matches button to get to your DNA matches page. Or click on the starred or green leaf matches to see just those matches. On your match list page, every DNA match who also has a matching ancestor to you in their tree is marked with a green leaf indicating a hint.

When there is a green leaf, clicking on the View Match button will take you to a page that will show you a picture of the expected relationship pathway (images of that on page 2 of this article).

Many times matches with no tree will actually have a tree that is just not connected to their DNA. You can see that on the view match page. There you can select it in the dropdown menu, as shown below, to get the usual sideways display with a surname list. Sometimes you can even figure out where they fit in from it.

I like to make Ancestry do the work of checking my assumptions by adding the tentative line to the tree connected to the DNA test. I put a “??” as the suffix when I am trying out a set of ancestors so that anyone copying my tree is warned that it is a test. Strange characters in the suffix box do not seem to affect the matching. Another perhaps better solution is to make your tree private while you experiment. Or to use a second small private tree that you connect your results to when trying out a possible ancestral line. You can change what tree and who your DNA is connected to on the DNA settings page. Get there from the button with a gear on the top right of your DNA home page.

Here are some examples of my experiments.
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Summer reading: DNA and historical novels

Jun30

You don’t have to be Norwegian-American to enjoy Candace Simar‘s novels about the lives and hardships of Norwegian settlers in Minnesota in the mid 1800s. Her characters became very real to me as I read about how they dealt with love, the Indian Uprising, the Civil War, losing children, losing crops, and just getting on with their daily lives. How self-sufficient those settlers had to be! The advent of the sewing machine was major, since they made all their own clothes. She even tells parts of these stories from the Native American point of view.

After I finished the fourth one I was sad that there were no more. In order the books are: Abercrombie Trail: A Novel of the 1862 Uprising, Pomme De Terre, Birdie, and Blooming Prairie.

A History of Scandinavian DNA

If Scandinavian DNA is what interests you, you might like My European Family: The First 54,000 Years by Karin Bojs as much as I did. Karin, a journalist, learns about her ancient ancestors, after DNA testing, by going around Europe interviewing DNA researchers and archaeologists.

With the popularity of autosomal DNA tests, many people are not aware of how interesting it is to know about their deep ancestry via Y and mtDNA haplogroups. The Eupedia website has detailed information about the origins and history of each European haplogroup.

Only Family Tree DNA tests fully for these, although 23andMe will give you your top level haplogroups. If you tested at Ancestry DNA, you can upload to Promethease.com – the health information site – to determine your basic haplogroup, see http://www.geneticgenealogist.net/2016/01/how-to-get-ydna-haplogroup-from.html for how.

Personally I like to keep a chart of my family haplogroups.

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Do my genes suggest I should drink less coffee?

Jun24

Whenever a new study is published linking a specific gene or SNP to a particular trait or health risk I go rushing to my DNA results to see what I have, so I thought I would share how I do that.

My latest worry is my coffee drinking habit.

There are so many coffee and caffeine studies that I am totally confused about what I should be doing. One caveat is that most of these studies are far from comprehensive and all of them need to be taken with a grain of salt. Have they really factored out all the other possibilities that could cause this result? Let’s face it, it’s early days yet in understanding what specific genetic variants do.

Personally when I read one of these articles, the first thing I do is google that gene name to find the associated SNP’s “rs” number so that I can find that variant in my results. For example let’s look at  rs762551, a SNP involved in the metabolizing of coffee.

While it is easy to look up a gene or SNP if you have tested at 23andMe or GENOS by using their browse raw data functions, what if you have only tested at Ancestry.com? Or Family Tree DNA, which has deliberately chosen not to test health related SNPs?

It’s actually pretty easy to look up a SNP in your raw data if you have downloaded it.

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My Adoption workshop and a success with GWorks

Jun3

Next Friday I am doing a workshop at the SCGS Jamboree in Burbank on using the tools at DNAGedcom and GEDmatch to solve unknown parentage cases. Since I like to have slides that are screenshots for my attendees, I decided to grab a few images using the latest and greatest GWorks on a missing father search case whose maternal half brother’s results were just in.

The basic technique for finding an unknown parent is to search the trees of close DNA matches looking for an ancestral couple shared among many of them. Build the tree down from that couple until someone is in the right place at the right time. The more you know about the unknown person(s) the easier this is. See the top of this post of mine for a summary – http://blog.kittycooper.com/2017/01/a-jewish-adoptee-finds-his-birth-family/

It has been a while since I used DNAGedcom. Why? Because now that Ancestry.com DNA has over 4 million testers, many adoptees get lucky and as soon as their DNA results are posted, they have enough good matches to figure out who at least one birth parent is. Also the use of a mirror tree with a second cousin’s information can often identify the family branch they are looking for (see http://www.borninneworleans.com/how-to/what-is-a-mirror-tree/ for that technique).

However when there are only third and fourth cousin matches, the remarkable tools at DNAGedcom.com can help you solve your mystery, but it is not intuitive or easy. It works best for folk with deep American roots, since that is the most tested population at Ancestry.com.

GWorks is a tool at DNAGedcom designed to automate comparing the people in all the different trees of your DNA matches. With an inexpensive subscription, you can use their “client” to aggregate the results from each different testing site and the people in the trees at ancestry. You can also manually upload Gedcoms which are easy to generate from ahnentafel lists (for that technique see http://blog.kittycooper.com/2016/10/text-to-Gedcom-using-ahnen2ged/ ). Then you get GWorks to compare all those trees looking for common people.

Much to my amazement, as I took screenshots of the GWorks process using my case, I was suddenly able to solve it! And he had NO good paternal side matches! It was all from the trees of fourth cousins. And done in two days using GWorks. (OK, once I saw that I had it, I stayed up until 2:00 am building the tree, I admit it, still…)

So how did I do this?

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Norwegian or English? DNA ancestry predictions

May29

My third cousin Irene (found with DNA) complained to me via email that her ethnicity results at 23andMe were very different from Ancestry; what was going on? Irene’s recent ancestry is known to be half Norwegian (my side) and half Scottish with some Irish (about 6% expected) mixed in.

Ancestry’s predictions are on the left, 23andMe’s estimates are on the right

So I looked and saw that 23andMe (above right) has a very low estimate for Scandinavian for her, while the British and Irish (her Scottish) is fine. Ancestry DNA (above left) has the Scandinavian predicted correctly but calls her Scottish both Irish and Western European. At least it includes her in a Scots genetic community which is correct and very cool.

Family Tree DNA’s predictions

Since I had also uploaded her DNA results to Family Tree DNA, I checked there and saw that they correctly predicted 49% Scandinavian. However the Scottish shows as 36% British Isles followed by some traces including 9% East Europe? No one else saw that!

One of the problems is that our Viking ancestors visited and even settled in various parts of the British Isles making it hard to tell British from Scandinavian. Also there was more migration within Europe many hundreds of years back than we might realize. Finally each company uses different reference populations and techniques for their ethnicity estimates.

Predicting where your ancestors originated based on your DNA test is just not that accurate yet. The broad strokes are pretty good, but since the actual percentages vary quite a bit from company to company it is easy to see that there is much improvement needed.

Somewhat alarmed that 23andMe, which I had always thought was the most accurate of the three, did not predict Irene’s Scandinavian correctly, I decided to double check the predictions for my Norwegian-American Dad, as well as my brother who is tested at all three of the main companies.

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