DNA testing: Is it worthwhile?

My experience with DNA testing

I have come to a few roadblocks in my family tree, so in August this year I decided to see if DNA testing could help. In case anyone else is interested in going down this path, I have put together a few notes on my experiences.

What is DNA all about?

This is something I should have researched more before I started, and would recommend anyone else undergoing DNA testing does so. I am slowly finding out the basics and how to interpret the results.

As DNA is a bit like a zipper – pairs of chromosomes, one from each parent – you will share your DNA equally with your mother and your father. Each of your four grandparents will have contributed 25% to your DNA, each of your 8 GGrandparents 12.5% and so on. (There can be very slight variations due to X and Y chromosomes but I won’t go into that here).

Once you reach your GGGG Grandparents, some of your ancestors will start dropping off your DNA profile, i.e. it is not possible to represent ALL your ancestors in your DNA meaning that a particular ethnic group (though represented in your family tree) may not show up in your DNA at all.

Siblings will share approximately 50% of your DNA (this is random chance so may vary slightly), aunt/uncles approximately 25%, first cousins approximately 12.5% and so on.

The process

There are several companies doing DNA testing. I chose Ancestry.com so that I could compare my results to other Ancestry.com members and receive notifications when other tested members share my DNA. They test Autosomal DNA which identified genes from both male and female ancestors.

1. I paid online (total cost was about $160, $30 of which was postage) and sent my request in August. Ancestry.com advised the process would take 6 to 8 weeks.

2. A week later I received my test kit. It was very straightforward and simple. A sample of saliva is required.

3. Return postage and packaging was provided and I produced the sample and sent it off about a week after it arrived at the start of September. At this point I also activated the test online (each test kit comes with a unique identifying number). When activating online I chose to make my results publicly available to those people with matching DNA and opted to link the results to my ancestry.com family tree.

4. Ancestry kept me updated at all stages via email, notifying me when my kit was posted, activated, had arrived for processing, had started testing, had completed testing.

5. The results are available online only at the ancestry.com DNA website. These arrived sooner than I was expecting, at the start of October.

The results

1. Ancestry provides a basic breakup (in percentage form and displayed as a pie graph) of your ethnic DNA makeup. Mine was partly expected and partly very surprising.

2. My maiden name is McLeod and many of my ancestors are from Scotland and England, and yet my UK DNA was less than 1%. This created even more questions for my family tree research. Had all of these ancestors dropped out of my DNA, or did they come to the UK long before from somewhere else?

3. Large hunks of my DNA were from expected ethnic groups e.g. Greek and Irish, but other regions of the world popped up to surprise me e.g. Finland, The Iberian Peninsular, India and European Jewish to name a few. I turned out to be a real Heinz 57 variety. Looking at other people’s DNA makeup- this is not the case with everyone.

Lost cousins

1. Ancestry.com provides a list of other people who have been tested and who match your DNA. They are sorted from closest match to furthest match, and grouped in expected relationship groups, e.g. 2nd to 3rd cousins, 4th to 6th cousins, 5th to 8th cousins (this is about as far back as they go). These matches are updated weekly. They also advise you if there is a shared ancestor in any of the family trees. So far I have 30 pages of DNA matches – with about 20–25 people per page!

2. If the people you match have linked a family tree to their results, ancestry.com will show you any shared surnames occurring in both your trees, and map locations of ancestors’ birthplaces and whether or not these are shared between your two trees. You may then expand the siblings and their descendants in your tree to find possible links and matches.

3. There is also a function that shows if a particular match also shares a match with any other people in your DNA list – meaning the three of you (or perhaps even more) are related to each other. I have several of these groups – some are relatives who have been tested, others are completely unknown to each other.

4. Contact details for matching DNA members are provided and you can then communicate with each other to advance your research.

Successes and failures

1. If Ancestry.com members have a private family tree, or have not linked a family tree to their results, then it is not possible to see how you may be related and the results are pointless unless you can contact them and get access to their tree. I have found some members respond well to contact and will work with you to find relationships, others will not answer your emails.

2. My greatest success has been working with a distant cousin from the UK. We matched only a locality in our family trees, but after expanding our siblings, have discovered our families share many of the same surnames and are intrinsically linked through intermarriage in that one locality.

3. My greatest failure has been finding the strongest match on my DNA list had a private family tree, discovering they also share matches with me and five other tested members, only one of whom had a public family tree. I have written to this excellent match a couple of times but had no response. This is my strongest possibility of finding a link through one of my family tree roadblocks, but although the information must be there, it is totally unavailable due to the unwillingness of others to share information.

What next?

1. I have also decided to have other members of my family tested to help narrow connections through group matching and excluding. My mother, sister and several cousins are having their DNA tested.

2. I have downloaded my DNA from Ancestry.com and uploaded it onto a website called GEDmatch (this was done at the request of one of my Ancestry DNA matches). The process was fairly simple but took quite some time – several days before results were fully processed. This has provided more in depth results of DNA makeup and offers more tools for research. The site is free and allows you to:

  • Read and research DNA information.
  • Check DNA makeup through several different systems.
  • Match with other tested members in minute detail e.g. exact matching chromosomes and degree of match,
  • Check if your parents are related to each other (just from your own DNA),
  • Check predicted eye colour,
  • Obtain visual representations of your DNA makeup etc

I have yet to fully explore and understand this website, but will keep anyone interested updated with its usefulness.

Is DNA testing helpful in family history research?

Definitely yes.

I will be happy to assist anyone interested in undertaking this method of research, or share future insights.

Tracey Treloar