DNA Testing for Genealogy

Several friends have asked for advice on DNA testing for studying their family history; this is a summary of advice for 2017.

Be Prepared for Surprises

The first thing that I tell people is to be prepared for surprises:

  • If you have white ancestors who lived in the South during the slavery and reconstruction eras, it is highly probable that you will get a DNA match from a second, third, fourth or fifth cousin who is black. Slave owners raped female slaves, who then got pregnant and had children. Given the number of fourth cousins that you have, it is almost a certainty that you will have at least one genetic match who is black.
  • Your parents or grandparents may not be your biological parents or grandparents. It is not routine, but it is also not unusual for your dad not to be your dad.
  • You may discover siblings that your mom or grandmother had out of wedlock. Again, this is not routine, but it is also not unusual.
  • Some relatives may have committed crimes with no (or very long) statutes of limitations (or think someone else did) and may be adamantly opposed to DNA testing for no apparent reason. The genealogy DNA testing services intentionally fail to keep an evidentiary chain of custody, but this will not allay the fears of some family members.

Who Should You Test?

The short answer is the oldest living generation that you can. The long answer depends upon the specific genealogical research problems that you are trying to solve. To prove/disprove a particular relationship from the late 1700s, I am trying to find someone provably descended from a potential male direct line who has done a Y-DNA test. We would not know whether we are related until after testing has been done.

Generally, try to get tests from parents and grandparents who are living, and then look for specific people to solve specific problems.

What Tests Should You Purchase

The key for all of the testing services is to get a DNA sample, and have a single test done. Once they have a sample, they can do additional tests from that sample at a later date as your are willing to spend more money. The short answer for parents and grandparents is everything:

  • For men, get a Y-DNA, autosomal DNA and mitochondrial DNA tests done.
  • For women, get both autosomal and mitochondrial DNA tests done.


Only men can take this test. It can prove/disprove a match the direct paternal line for many generations, as there is no dilution from one generation to the next, and the mutation rate is generally about one every four generations.

Autosomal DNA

Both men and women can take this test. It can identify the presence of a relationship back about four or five generations, but it will not tell you what the relationship is. It is diluted 50% with each generation, and is thus limited to about five generations.

Mitochondrial DNA

Both men and women can take this test. It can prove/disprove a match for the direct maternal line for many generations.


Both men and women can take this test. This is a specialized test that is useful only proving very specific relationships.

Which Service Should You Use

This is a long complicated subject; people with unlimited budgets test with all of the services, since the value of each service is related to the number of people who test with that service. Some of the services allow you to unload data from competing services and upload it to their service, but this is not universal and changes from year to year. The key to testing parents and grandparents is to get a sample kit activated at both the Family Tree DNA and Ancestry DNA services. It probably helps to outline the major testing services:

All of the services offer an estimate of your ethnic origins; those who have tested with multiple services laugh at this, as each service gives different, and sometimes significantly different results.

If your parents or grandparents are the first generation to immigrate to the US, you may want to look at testing with MyHeritage, as it may have a larger European population for matching.

Test Men with Family Tree DNA and Optionally Ancestry DNA and/or MyHeritage

Family Tree DNA is the only service that offers the Y-DNA test, so you should get a kit from Family Tree DNA and do at least the Y-DNA test with them. You can do an autosomal test with either Ancestry or Family Tree DNA. I would recommend getting kits from both, doing Y with Family Tree DNA, and autosomal with Ancestry, then upload your Ancestry autosomal info to Family Tree DNA. At a later date, you can optionally order an autosomal or X-DNA test from Family Tree DNA. The key for testing parents and grandparents is to get the samples to each of the services.

Test Women with Family Tree DNA and Optionally with Ancestry DNA and/or MyHeritage

It is not clear that Ancestry offers a mitochondrial test, so I recommend ordering a mitochondrial test from Family Tree DNA and an autosomal test from Ancestry, then upload your Ancestry autosomal info to Family Tree DNA. At a later date, you can optionally order an autosomal or X-DNA test from Family Tree DNA.

For Genetic Diseases, Test with 23 and Me

For most people I would not recommend testing with 23 and Me due to concerns about privacy. Both Family Tree DNA and Ancestry DNA were created primarily for genealogical research and intentionally chose genetic markers that have no known disease information; if you testing results were to become public, it would not have an effect on your insurability.

23 and Me was formed primarily to build a pool of people with specific health-related genetic information to make it easier for pharmaceutical companies to do clinical trials for drugs that are targeted for specific populations, like women who are negative for the BRCA2 breast cancer gene. For this reason, the 23 and Me privacy policy is very different from the privacy policy at Family Tree DNA and Ancestry DNA.

If you are interested in health information, 23 and Me is the only option, but make sure that you understand the privacy policy and the implications for purchase of 23 and Me by a pharmaceutical company.

DNA Seminars

The Dallas Genealogical Society has a DNA Special Interest Group that meets at the downtown library on the third Thursday evening each month.

Diane Southard and Cece Moore are among many consultants that hold frequent seminars and speak on DNA topics at local historical and genealogical societies.

Day 2– June 18–Edinburgh Castle and Seminar Dinner

We started the day with sleeping in, checking out of the Hub Haymarket Hotel, taking the tram to the Apex Waterloo Place Hotel that was part of the NEHGS research tour, and breakfast. First, the hotel Hub Haymarket is a very convenient and inexpensive hotel if you are planning a trip to Edinburgh. It is one minute from the tram line, and a 10 minute tram ride to the Scottish National Archives. The food choices are limited, but we found a great Vietnamese place about 50 yards away. The Apex Waterloo Place is a full service business hotel that is centrally located with prices to match.

We had breakfast at Pep and Fodder, a few doors down from the Apex Waterloo hotel where the seminar is based. This could become our culinary home base–inexpensive and good. We walked up to the Royal Mile and turned right (W) to head to Edinburgh Castle, where we spent the afternoon. The Royal Mile reminded both of us of the Rambla in Barcelona; one of the highlights was a Celtic quartet that talked a group of Irish college students (all women) into doing an Irish dance. They were far from Riverdance, but it was clear that they all knew the basics. When visiting the castle, make sure to stop for tea at the Red Coat tea room on the north side of the castle. Go the north room (not immediately obvious) and get a table near the windows to enjoy your tea. The view is incredible; this is a great place to regroup and figure out the plan for the second half of your visit. For photography, late afternoon provides some great opportunities.

The view of Edinburgh from the castle is breathtaking.
Edinburgh-Edinburgh Castle View

Kristin returned to the hotel at 2:30 to get ready for the 3:00 to 5:00 orientation session for the seminar, and I returned at 4:30 in time to shower and nap before the 6:00 dinner at Howie's, where I had haggis, neeps and peeps for the first time. I will do this again; haggis is much better tasting than it sounds. It is really just a peppery sausage without the casing.

Dinner was a lot of fun with discussion on Segues, Master Genealogist, GRAMPS as a replacement for Master Geanalogist (see tmg2gramps by Coherent Software, LaTeX and frustrations with genealogical citation, lasers, physics, laser physics, and a host of interesting topics.

Hagis, Neeps and Tatties
Edinburgh-Hagis, Neeps and Tatties


Google Map for National Archives of Scotland and Nearby Hotels

Day 1– June 17–Tour of Hadrian’s Wall

For our first full day and only full day before Kristin started in on the NEHGS research tour, we had pre-booked a tour of Hadrian’s wall with Rabbi’s, one of the big bus tour companies. The tour left at about 8:00, so we checked the tram schedules and routing on Google Maps and set our alarm for about 6:30 to allow time to get there and find breakfast. Google Maps and Bing Maps are fantastic for figuring out public transportation when travelling.

The Rabbie’s Cafe is convenient, but it is mobbed in the morning when tours leave.

The tour was time and money well spent. Hadrian’s wall would be a major construction and garrison project today, and was clearly a major undertaking when it was constructed. The fact that there are really two walls–Hadrian’s and Antonine–is pretty amazing.

The railroad bridges and aquaducts around Edinburgh are spectacular
Hadrian's Wall Tour-River Tweed
Hadrian’s wall did not dissapoint.
Hadrian's Wall Tour-The Wall

We were exhausted at the end of the day and did takeout from the convenience store for dinner, since the Vietnamese place was closed.

Day 0–June 15/16–Travel to Edinburgh for Kristin’s NEHGS Scotland Research Tour

Kristin signed up for an NEHGS Scotland Research Tour in June and we decided to make a long trip and combine it with the UseR! 2017 statistics conference in Brussels a week later. This meant that I had to figure out how to keep busy for a week in Edinburgh and she had to figure out how to keep busy for a week in Brussels, both difficult and arduous tasks. We planned to do the week in between in the Glasgow area doing research on Kristin’s ancestors from there

Our flight from JFK to Edinburgh was uneventful but interesting; our seatmate in the window seat was a guitarist for a band called Dan Baird and Homemade Sin. We had an interesting conversation about the music industry and how it has changed over they years.

After dropping bags off at the Haymarket Hub hotel (no rooms for check-in at 8:30 am), we walked to the city center and picked up a hop-on hop-off bus to see the city. The walk through the Princes Street Gardens was quiet and a great respite from the surrounding Saturday traffic.

Princes Street Gardens in Edinburgh, Scotland with Edinburg Castle to Right and Princes Street to the Left
Princes Street Gardens in Edinburgh, Scotland with Edinburg Castle to Right and Princes Street to the Left

I was stunned at the number of tour buses. The tour was really pretty amazing, even though we were tired. I will be busy while Kristin is doing research.

We were exhausted, so we stopped for lunch at Belle Italia, an Italian chain–I know, it is just wrong to eat Italian when traveling in Scotland. It was a lucky find. They had a spaghetti with lentil sauce that was excellent and unlike anything we've had before. My lasagna was also quite unusual...two layers in a cast iron skillet. We will go back if there is time.

After going back to the hotel for a nap (I didn't sleep in the flight, so I was several hours past doing an all-nighter) we went out to find something simple for dinner. The pub connected to the hotel was was unpleasantly noisy, so we went to the one across the street, which didn't serve food until 9:00. We next tried a pizza place...which turned out to require reservations. We ended up with sandwiches from a convenience store; a tuna with corn, salmon and cream cheese and a ham lettuce and tomato.

It turns out that the combination of adapters that I brought will not work in a UK plug, so I've got to get another adapter at some point.

For purposes of genealogy research trips to the Scottish National Archive, the Haymarket area is much cheaper than the area around the archive and is only a 10 minute tram ride. Dining options are limited.

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