Why take a DNA test to find ancestors
Taking a DNA ancestry test can transform your understanding of the past, helping you to smash brick walls and find long-lost relations in your family tree research. Discover why you should take a DNA test to enhance your family history....
1. Discover your ancestry with a DNA test
Take your family history research to a new level, using DNA testing to complement your paper-based findings and help you to find living relatives and solve age-old family history puzzles in a way which traditional documents never could.
2. Break through a brick wall using DNA
Family tree brick walls, some of which were unsolvable before the advent of DNA testing, can now be solved with the help of a test. By finding living relatives who share your DNA, a brick wall such as an ancestor with unknown parents could be solved.
3. Connect with family & more distant kin via a DNA test
An autosomal DNA test can be taken by both males and females, and the results of your DNA test are then placed into a matching database - enabling you potentially to connect you with genetic cousins on your family tree. These new-found relatives may have documents and photos relating to your family tree, allowing you to help each other with your research.
4. Taking a DNA testing is simple
Taking a DNA test couldn’t be simpler. Most family history DNA tests require just a cheek swab or a sample of saliva, which you submit to the testing company, and then sit back and excitedly wait for the results (which are usually available in not a great deal more than a month).
5. Test now and help future researchers with DNA
The more family historians who take a DNA test, the higher the chances of everyone finding matches for their tree. The databases become larger with each person who tests, and so even if you don’t immediately solve your family history mystery, there’s always the chance someone new to DNA testing will be connected to you – with great results.
6. Verify your family history research using DNA
Whether you’re new to tracing your ancestors, or have been building your family tree for many years, a DNA test is the perfect way to be sure that your research is rock solid and you’re tracing the correct ancestors.
7. Research your surname with the help of DNA
The latest advances in DNA testing and the growth of DNA surname projects can allow you to narrow down your paper-based research. If your male-line surname is fairly common, your DNA results will potentially allow you to be sorted into a sub-set of that surname, giving you a more focused group of men among whom the DNA predicts will be your ancestors.
8. Follow the trail of migrant ancestors with the help of DNA
A DNA test is a great way to see when and where your ancestors migrated over the centuries, providing information which traditional paper-based sources often can’t. For example, if your ancestor migrated to the USA during the Colonial era, there will be few records showing where they came from – whereas a DNA match can help provide a location to search for records for your immigrant ancestor.
9. Find your biogeographical DNA mix
One of the most exciting things about receiving the results of a family history DNA test is discovering your own biogeographical mix, with results that show the percentages that make up your own ethnicity. For example, you may believe your ancestors have lived in the UK for hundreds of years, but when your results arrive, you might be surprised to find you have 25% Italian ancestry, and a tantalizing 3% Scandinavian ancestry. While your biogeographical mix is exciting, do be aware that it is subject to change - as the testing companies refine their estimated information over time.
10. DNA test affordability
DNA testing is now much more affordable than in previous years. Modern DNA tests can provide you with more information and details about your ancestry than ever before, so now is the perfect time to take the plunge and begin your DNA family history adventure.
Look out for DNA test sales! The family history DNA test kit market is a very competitive one and sales are run through the year - so keep an eye out for discounts.
Case study: How to use DNA to trace a missing grandparent
Fish in all the ponds
Michelle Leonard, of Genes and Genealogy, shares advice for Family Tree reader L.J. on how to use her DNA to try to trace her missing grandmother.
Michelle writes:
I work on unknown grandparentage mysteries on pretty much a daily basis for clients and have solved a large number of them so the first thing to say is that it's definitely possible! Don't give up hope with it even if you have to wait for some better matches to come along.
Of course each case is individual and there can never be any guarantees but you have around 25% of the mystery DNA to work with from testing yourself and that's a sizable proportion. The first thing you need to make sure of since you can't test others is that you're fishing in all the ponds with your own DNA as you just don't know where the best matches for this mystery may choose to test.
Eliminate matches
The key then is being able to isolate the matches on the mystery quarter. It's great that you've been able to test your mother to eliminate the matches on her two quarters so that leaves the mystery quarter and the matches to your paternal grandmother's line.
Build a robust tree
Being able to test someone on your paternal grandmother's side of the equation could certainly help but it's not essential if you can't find anyone. The most important thing in that case is to build her tree as accurately and robustly as you can and then use the information on her ancestral lines to identify matches that are on that quarter. You should be able to group them into clusters and hopefully you will be left with the matches that are on the mystery quarter.
Isolate the matches on the mystery quarter
Once you have managed to isolate the matches on the mystery quarter it's then a case of working on those matches and specifically using the shared matches in that group to help identify sets of common ancestors. If you can identify a set of common ancestors between the shared matches, then it's very likely that you too share those common ancestors or a set of their parents.
It sounds like you might already have a good clue to go on if there's a group of matches that all relate back to a particular Barnes family in Oxfordshire although the amount of DNA shared is quite low. You have to first establish at which generation you share both ancestors so build a tree for these Barnes matches back to their 2nd and 3rd great-grandparents and then look for matches to both the 3rd great-grandfather and 3rd great-grandmother - by that I mean matches who perhaps descend from siblings or cousins of theirs so that they are only on one line or the other. If you can find DNA links to both then it's very likely you descend from both and it's a case then of working down to the next generation and seeing if you can find links to any of the spouses on that generation in order to narrow things down.
Work your way down the generations
Ultimately you want to work your way down the generations until you get to one or more candidate males who could have been in the right place at the right time and then it's a case of seeing if you can get descendants on those lines to target test to prove or disprove the hypothesis.
Using Ancient DNA to trace the human story
Learn more about our shared human story and your deep ancestry with Ancient DNA. Dr Diane Brook shares useful further reading links below, and we share her writing (from her article in the August 2024 issue of Family Tree) on the New Grange burial in Ireland and the way in which DNA is now proving ancient Irish history.
"Archaeologists have long wondered if tombs which held many burials (where still untouched until modern times) were tombs of the whole community, an elite, or one kindred,” writes Dr Diane Brook, in the forthcoming August issue of Family Tree. “Ancient DNA is starting to answer these questions,” continues Diane.
“The Hazleton long barrow in Gloucestershire, excavated in 1979-82, held 35 burials. The DNA now shows that there was one man with four wives and their children and grandchildren with others the partners of the children. Each wife and her descendants were in a separate area of the tomb. In this case, an elite single family were provided with this huge monument, in use for only about a hundred years from 3700 to 3600 BCE.
"Another study, of chamber tombs in Ireland, from 3900 to 2500 BCE, showed smaller, simpler tombs did not contain related people between different sites. They major tombs, far apart, did have related male burials, two in Sligo, and one each in Meath and Down, strongly suggesting a powerful elite. Most interesting is the New Grange burial, about 3200 BCE of the man in the most special position just to the side of the passage end, by the carved stones where the mid-winter sun hits.
"His DNA showed he was the product of incest; parent-child or brother-sister. This is usual only in royal elites such as the Pharoahs and Hawaiian royalty. Three ancient Irish stories refer to incest in royal families and events involving Newgrange. It is hard to believe this is continuous tradition but I would love to think Irish ancient 'history' treating as mythology, has some basis in fact."
Pushing back the boundaries of pre-history, in the August 2024 issue of Family Tree Diane Brook takes the long view, combining her interests in archaeology and genealogy to piece together an account of our shared human past as revealed by artefacts, remains and DNA.
Useful links and websites for learning about Ancient DNA
Genealogy sites offering Ancient DNA comparisons
- 23&Me (paid test) – Neanderthal.
- LivingDNA (paid test) – Viking, Classical, Neanderthal, Denisovan.
- FamilyTreeDNA (paid tests) – ancient European groups, WHG, EEF, Yamnaya.
- Gedmatch (free site, registration required) – Archaic DNA matches, free tool.
Haplogroups and Haplotrees
Learn more about haplotrees and haplogroups and better understand the ancient human story.
- SNP Tracker
- FamilyTreeDNA Public Haplotree
- International Society of Genetic Genealogy
- Wikipedia
- Mt-DNA
How to find out if you are the sole living descendant
Dr Sophie Kay explains a simple way to use your DNA test results to discover whether you are last living descendant on a particular line of your family tree.
Genetic genealogy connects us to biological relatives in the modern day who have inherited the same segments of DNA from a shared ancestor or ancestors. We therefore need other descendants of a particular ancestor to exist in the first place for there to be any hope of them showing up on the major genetic databases.
If you are the sole living descendant of a particular line then there may be nobody else to match to – but how to diagnose this?
Return to your traditional (paper-based) research on the line of interest and identify the siblings of your direct-line ancestors (up to, say, 3x-great-grandparent level). Produce these collateral lines forwards using traditional research in records such as:
- Wills and probate records;
- Civil registration certificates;
- Newspapers – including marriage announcements and obituaries;
- Electoral registers.
Observe how many children there are at each generation – and what happened to them. If the collateral lines from your branch of interest have consistently small families, or do not go on to have children of their own, then the line can die out.
Consider the imprint of major historical events too: if the young people in this branch’s collateral lines suffered a high death toll during wartime, this can also result in you being the sole living descendant.
Sadly there’s not much you can do to remedy this by working only with autosomal DNA, but triaging the problem is a great sanity-check and helps you understand that absence of matches.
Dr. Sophie Kay is a professional genealogist at Khronicle and an AGRA Associate, with over 17 years’ experience in family history research across the British Isles. She is the Ancestry and Genealogy Expert for TimeTeam; the DNA & Genetic Genealogy tutor at the Institute for Heraldic and Genealogical Studies; and tutors courses in historical maps and research methodology at Pharos Tutors. A qualified research scientist from the University of Oxford, she is also trained in DNA extraction, genetic analysis and Latin translation. Sophie also loves to pique people's interest with historical occupations and runs the #OccupationOfTheDay hashtag on Twitter, where she showcases mush fakers, leggers, pulpit men and steeplekeepers, to name just a few!