When asked about how database size affects ancestry results, David Nicholson, co-founder of Living DNA, told us, “The tests absolutely rely on the reference database. If you have Polish ancestry but there are no people in the database who are Polish, then what the test will do is show what the next closest group is next to Polish, like German or Eastern European ancestry.” Each ancestry DNA service has its own sample database and reference panel made of the DNA samples collected from their users and information collected from sources like the 1000 Genomes Project. The database consists of all this information collectively. A reference panel is made of certain curated samples with known family history and roots in a specific place. The services use insights gleaned from the reference panel to give you geographical ancestry results. In theory, a larger database leads to more information available to create a good reference panel, which then leads to better results for customers.  
Once your genetic information is out there, it’s difficult to undo. Also, once you know something about yourself, it’s impossible to un-know. Revelations such as having different parents than you expected or finding unknown half-siblings are difficult to process at any age, but it’s particularly troubling for kids. However, you can always simply opt out of family matching features.
For our evaluations, we assembled a group of testers willing to spit into a tube on camera. We chose four individuals of varying backgrounds. Two had previously taken one or more DNA ancestry tests, and two had not. Two had fairly well-documented family histories to compare against, one was adopted, and one had information about one side of the family, but not the other. All of us took DNA tests from AncestryDNA, 23andMe, National Geographic and Family Tree DNA. One tester also took each of the five additional tests we reviewed. After collecting spit and cheek cells, we mailed all of the tests at the same time and waited for results, noting all communications from the company in the meantime and how long it took each service to notify us that results were ready to view. We collected data based on testers’ impressions of their results, each service’s features and extras, how easy it was to use and navigate the service’s website, along with several other factors. We added this testing data to rigorous research and information gleaned from conversations with representatives from Ancestry, 23andMe, MyHeritageDNA, LivingDNA, Humancode (now owned by Helix) and 24genetics. 
As my dad and I have begun to explore our genealogy over the past seven years or so, we’ve found that our family is largely from Spain, which is no big surprise. Colombians have a wide range of ethnicities, which explains why many Colombians, including my mother, have white or fair skin with blue eyes. My dad also suspects we have German ancestry somewhere back there.
Of course, most DNA used by law enforcement in the U.S. does not come from direct-to-consumer DNA tests. The federal government and many states collect DNA samples from suspects of violent crimes after arrest or due to probable cause. These samples are added to the Combined DNA Index System, or CODIS, which is a national database for forensic information.
DNA tests offer a wealth of insights into your connections to family, history and geographical locations. They both entertain and encourage you to dig into what you know about yourself. The tests make great gifts to bring you closer to your family and involve you and your family in the development of a cutting-edge science at the same time. Beyond that, the information is extremely useful for adoptees, people looking for lost relatives, genealogists and for medical science. 
Although FamilyTreeDNA is the only DNA testing company openly working with law enforcement, other DNA companies don’t necessarily keep your DNA information private. Many direct-to-consumer DNA testing companies sell your data to third parties. For example, 23andMe shares customer data with pharmaceutical giant GlaxoSmithKline, which uses the information to develop medical treatments. In this case, you can opt out of having your DNA information used for research, and the data is shared only in aggregate.
Once your genetic information is out there, it’s difficult to undo. Also, once you know something about yourself, it’s impossible to un-know. Revelations such as having different parents than you expected or finding unknown half-siblings are difficult to process at any age, but it’s particularly troubling for kids. However, you can always simply opt out of family matching features.
A collaboration between scientists, researchers and genetic experts from across the globe, Living DNA has offered ancestry tests since 2016 while parent company, DNA Worldwide Group, has been operating since 2004. Our focus has always been on providing the world’s best collection of British and Irish historical records and while we’ve investigated the DNA market for some time, we hadn’t identified a partner that could truly bridge the gap between genetic genealogy and traditional family history research. Living DNA’s focus on British and Irish DNA makes them our perfect partner.
“My concern is that more and more of these tests are being put out, and people are being persuaded to have these tests done, and they get results back that are very often of very low value and dubious helpfulness,” she says. “And often people are told to go to see their GP and that then places a direct stress on the NHS, at no cost to the company. The companies make their profits and walk away, letting the NHS sort out all the fallout, the push-back, from the test results, in a way I find absurd. Why should the NHS have to prop up the problems that these companies create?”

Thank you for such detailed information. I’m considering buying a DNA ancestry kit for my wife for Christmas (and buying one for myself as well). After reading your article (and many of the wonderful comments), I’m leaning towards the one from Ancestry.com. However, would I still get complete results without a subscription? I looked on their website and it doesn’t say.


Otherwise, the home-testing kits could be said to fit in with our increasingly health-conscious and, if you wish to be cynical, narcissistic times. What says you’re “special” more than finding out everything about yourself, right down to the nitty-gritty of genetics? In this way, these kits could be viewed as the latest plaything of the “worried well”. You could see how the scientific approach would appeal to the health-obsessed of all sexes and ages, your marathon runners and serious gym-goers, who take their fitness extremely seriously.
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