DNA Ancestry Kits
Home DNA testing kits promise to tell us who we are and where we’re from- but are the answers they give us really as conclusive as the marketing encourages us to believe? Watchdog Live investigates.
We bought DNA ancestry kits from three prominent companies- 23andMe, Ancestry.co.uk and MyHeritage, to test the DNA of presenter Nikki Fox. The results differed for each service.
• MyHeritage told Nikki that her Ethnicity Estimate was 80% English, 20% Iberian (Spain/Portugal).
• 23andMe told Nikki that her Ancestry Composition was 99.9% European (including 61.8% British & Irish, 19.4% French & German) with Trace Ancestry of Broadly Sub-Saharan African.
• Ancestry.co.uk told Nikki that her Ethnicity Estimate was 82% England, Wales and NorthWestern Europe, 15% Ireland and Scotland, 3% Norway.
While there were some similarities, we couldn’t explain why, for example, only MyHeritage identified Iberia in the results; only 23andMe identified Sub-Saharan Africa, and only Ancestry identified Norway.
Our investigation found that the reason for the discrepancies between the results Nikki received are down to the fact that ancestry DNA testing kits can only provide an estimate of what your ancestry may be, based on comparing your DNA to the records of other people held by that company, and mapping where those people are from. This will be different depending how many peoples’ records are in the database, where they are from and who they are. There is nothing intrinsic in your DNA which allows a DNA ancestry service to give you concrete answers about where you are from, and the results cannot be taken at face value as giving a conclusive insight into your heritage.
Genetic genealogist told Nikki that the percentages given by these tests are generally accurate at a continental level, but are less reliable at national level- and that trace ancestry (such as Nikki’s Sub-saharan African result) simply isn’t meaningful. But she said that DNA testing can be a useful tool- when it’s used in conjuction with historical, family tree research.
Statement from MyHeritage:
"MyHeritage used a statistical procedure called Principal Component Analysis to ensure that each founder population is well-clustered, removing outliers and people who were mistaken about their own heritage. The end result became a very rich and consistent reference of 42 Founder Populations, considered to be the best of its kind in the world. MyHeritage DNA uses this reference when analyzing your own DNA, to identify your ethnicity breakdown among these 42 ethnicities, with percentages. This is your Ethnicity Estimate.
MyHeritage strongly advocates DNA testing in combination with the traditional arsenal of genealogical tools, such as personal and historical records, to draw a complete picture of the family relationship between individuals. Family trees are invaluable for understanding the relationship path to DNA matches and ethnicity estimates. Creating a family tree is recommended for anyone taking a DNA test, to make the most of the DNA results and to uncover the full story behind them. Over 107 million users worldwide have used MyHeritage to build over 46 million family trees and access 10 billion historical records."
Statement from Ancestry:
Ancestry is the global leader in family history and consumer genomics - with a 30-year history of empowering journeys of personal discovery to enrich lives. We harness the information found in 100 million family trees, more than 20 billion records, and the largest consumer DNA network in the world to help people gain a new level of understanding about themselves and their connection to the world.
Consumer genomics is a new and evolving field and Ancestry is at the forefront, consistently revealing new ways to learn about yourself through DNA. Ancestry’s industry-leading reference panel leverages thousands of DNA samples from around the world. Each sample in the reference panel has a long family history in one place. We compare our customers’ DNA to DNA samples from the reference panel to create their estimate.
With the largest consumer DNA network and continued investment in cutting edge science, Ancestry is able to determine our customers’ ethnic breakdown with a high degree of precision.
Through ongoing innovation in DNA science, digitizing historical records and automating research, we enable our customers to continually learn new insights. The more historical records added, the more DNA samples taken, the more family trees built - the more meaningful connections and discoveries customers can make.”
Statement from 23andMe:
“We strive to make a compelling product that is easy for customers to understand, while at the same time providing many additional layers of detail within the product experience to help them interpret their results. For example, within the Ancestry Composition feature we built an interactive tool that allows customers to explore their ancestry
prediction at different confidence thresholds, ranging from a speculative prediction to conservative (50% to 90% - see graphic below). In addition, our Ancestry Composition algorithm errs on the side of conservatism, so when we are unable to match a DNA segment to a specific reference population with confidence, we assign that segment of DNA to a broader region.
Our Scientific Details and Frequently Asked Questions (FAQs) are clearly signposted within the report - across the top banner - and offer customers a breadth of information and additional clarification about how we provide our ancestry estimates. While the Ancestry Composition results give a snapshot of your genetic ancestry prediction, each Ancestry Detail report goes into more depth about your genetic similarity to each of these reference populations, and includes language that makes the nuance of this estimate clear.
At 23andMe, over the past several years we have focused our efforts on improving equity and diversity in our reference datasets driven by programs such as our African Genetics Project and Global Genetics Project. These programs provide free kits to people who have four grandparents born in a variety of countries with underrepresented populations around the world). As a result of these efforts, we currently have more reference populations in both Africa (12) and Asia (22) than we do in Europe (10).”