Twins get 'mystifying' DNA ancestry test results (Marketplace)

CBC News

18 Jan 201921:15

EducationalLearning

32 Likes 10 Comments

TLDRThe video script revolves around the accuracy and implications of DNA ancestry tests, a popular consumer product that promises to reveal one's heritage. Charlsie, the host, embarks on a journey with her identical twin sister to test their DNA through five different companies: Ancestry DNA, 23andMe, MyHeritage DNA, FamilyTree DNA, and Living DNA. Despite being genetically identical, they receive varying results, which raises questions about the reliability of these tests. The video delves into the science behind DNA testing, featuring insights from experts like Dr. Simone Gravel, a population geneticist, and Timothy Caulfield, a health policy professor. They explain that the tests are based on statistical interpretations and comparisons to reference populations, which means results are not definitive. The script highlights that while the tests can be entertaining, they should not be taken as absolute truths. It also touches on the potential social issues arising from the misleading notion of discrete biological borders, emphasizing that humans are more similar than different. The video concludes with a call for more transparent and scientifically accurate marketing of DNA ancestry tests.

Takeaways

👭 Identical twins taking five different DNA ancestry tests received varying results, raising questions about the accuracy of such tests.
🧬 DNA ancestry companies claim to reveal your heritage but the results are actually statistical estimates based on a small percentage of your DNA.
🌐 Companies like Ancestry DNA, 23andMe, MyHeritage DNA, FamilyTree DNA, and Living DNA use different formulas and reference populations, leading to discrepancies.
🔬 The process involves comparing your DNA to reference groups in their databases, which is more of an informed guess than a definitive answer.
📉 Even the DNA of identical twins can yield different ancestry results due to the statistical nature of the analysis and the companies' proprietary algorithms.
📈 The confidence levels in DNA tests, such as the 50% confidence level mentioned by 23andMe, indicate that the results are not 100% certain.
📚 Population geneticist Dr. Simone Gravel explains that the results are not definitive and that there's a lot of statistical interpretation involved.
🔄 Ancestry results can change over time as companies update their algorithms and reference databases.
🎓 Health policy professor Timothy Caulfield suggests that these tests are more recreational than scientific and cautions against taking the results too seriously.
🌐 The most certain aspect of these tests is the continental origin of a person's DNA, not the specific country or region.
⚖️ The marketing of DNA ancestry tests may be misleading, as it overpromises on the precision and accuracy of the results, which are actually approximations.

Q & A

What is the main subject of the video?
-The main subject of the video is the exploration of the accuracy and reliability of DNA ancestry tests, using identical twins as a case study to highlight inconsistencies in the results provided by different companies.
How many DNA ancestry tests were conducted in the video?
-Five DNA ancestry tests were conducted in the video, involving companies such as Ancestry DNA, 23andMe, MyHeritage DNA, FamilyTree DNA, and Living DNA.
Why were identical twins used in the study?
-Identical twins were used because they share the same DNA, so any differences in the results from the DNA tests would highlight the potential inaccuracies or inconsistencies in the companies' methodologies.
What did the video reveal about the accuracy of DNA ancestry tests?
-The video revealed that DNA ancestry tests may not be as accurate as they claim to be. Even identical twins received different results from the same companies, suggesting that the tests are more of a statistical guess than a definitive answer.
What is the percentage of DNA that ancestry companies typically analyze?
-Ancestry companies typically analyze less than 1% of an individual's DNA, focusing on about 700,000 sections where they know there are slight differences or variants among humans.
How do the companies determine a person's ancestry from the DNA sample?
-Companies compare the patterns of an individual's DNA differences to groups of people in their databases and use mathematical models to estimate which groups the individual most likely belongs to.
What did the experts in the video suggest about the interpretation of the ancestry percentages?
-Experts suggested that the specific percentages should not be interpreted as definitive ancestry from a particular place. The most certain information that can be provided is at the continental level.
What did the video reveal about the potential changes in DNA test results over time?
-The video revealed that DNA test results may change over time as companies update their databases and mathematical models. This indicates the imprecision and evolving nature of the science behind these tests.
What is the stance of health policy professor Timothy Caulfield on the ancestry business?
-Timothy Caulfield believes that the ancestry business is selling something that isn't really supported by the science. He refers to it as 'recreational science' and suggests that the results should be taken as an approximation and not too seriously.
What message does the video convey about the concept of biological borders?
-The video suggests that the notion of discrete biological borders is scientifically incorrect and potentially socially problematic, as it could reinforce ideas of nationalism and tribalism.
What is the final advice given by Charlsie in the video regarding DNA ancestry tests?
-Charlsie advises viewers not to put too much weight on the results of DNA ancestry tests. She suggests that while they might be fun, they should not be taken as definitive proof of one's heritage.

Outlines

00:00

😀 DNA Ancestry Tests: Identical Twins, Different Results

Charlsie and her identical twin Carly embark on a journey to explore the accuracy of DNA ancestry tests. They purchase kits from five different companies and, despite being identical twins, receive varied results. Charlsie expresses skepticism about the accuracy of these tests, especially when their heritage is reported differently. The video highlights the growing curiosity and popularity of DNA testing, with millions seeking insights into their ancestry.

05:01

🧬 Understanding DNA Ancestry Tests: The Science Behind the Results

Dr. Simone Gravel, a population geneticist, explains the process of DNA ancestry testing. He clarifies that these tests are not definitive and involve statistical interpretation and comparison to reference genomes. The video points out that companies only analyze a small fraction of one's DNA and use mathematical models to estimate ancestry. Charlsie interviews Timothy Caulfield, a health policy professor, who criticizes the industry for misleading consumers and selling 'recreational science.'

10:02

👭 Twin Test Results: Discrepancies Among DNA Ancestry Companies

Despite having identical DNA, Charlsie and her twin receive different ancestry breakdowns from various companies. The video discusses the surprising results, which include differences in the percentage of Eastern European and Italian ancestry. The Yale team, including Mark Gerstein, investigates and finds no differences in the raw DNA data, suggesting the discrepancies lie in the analysis methods used by the companies.

15:03

🤔 The Inconsistency of DNA Ancestry Results: A Closer Look

The video delves into the inconsistencies of DNA ancestry results, even among identical twins. Charlsie and her twin's results vary significantly across companies, raising questions about the reliability of the tests. Experts suggest that the differences are likely due to each company's unique algorithms and reference databases. The video also addresses the fact that results can change over time as companies update their databases.

20:05

🌐 Broader Implications and the Human Genome: A Call for Accurate Messaging

The video concludes with a discussion on the broader implications of DNA ancestry testing. Charlsie highlights the booming industry fueled by marketing and human curiosity. Caulfield raises concerns about the subtle messages in marketing that suggest biological borders between populations, which is both scientifically incorrect and potentially socially harmful. The video emphasizes that humans share more than 99% of their DNA, reminding viewers of our shared genetic heritage.

Mindmap

Keywords

💡DNA Ancestry Tests

DNA ancestry tests are commercial services that analyze an individual's DNA to provide information about their genetic heritage and ethnicity. In the video, identical twins take five different DNA ancestry tests to explore the accuracy and consistency of the results, which are central to the video's theme of questioning the reliability of such tests.

💡Identical Twins

Identical twins are siblings who have the same genetic material because they originate from a single fertilized egg that splits into two. In the context of the video, the use of identical twins as subjects for DNA tests is meant to control for genetic variation, highlighting the discrepancies in the results from different companies.

💡Statistical Interpretation

Statistical interpretation involves using statistical methods to analyze and draw conclusions from data. In the video, this concept is crucial as it explains how DNA companies use statistical models to estimate an individual's ancestry based on their DNA sample, which is not always 100% accurate.

💡Population Genetics

Population genetics is the study of how genetic variation within and between populations evolves over time. A population geneticist featured in the video explains the process of DNA analysis, emphasizing that the results are guesses based on statistical models and the reference genomes used for comparison.

💡Ancestry Companies

Ancestry companies are businesses that offer DNA testing services to trace a person's heritage. The video scrutinizes the claims made by these companies, such as Ancestry DNA, 23andMe, MyHeritage DNA, FamilyTree DNA, and Living DNA, regarding the accuracy of their ancestry reports.

💡Confidence Level

In the context of DNA ancestry testing, the confidence level indicates how sure the company is about the accuracy of the reported ancestry percentages. The video reveals that 23andMe, for example, has a default confidence level setting of 50%, meaning the company is at least 50% sure of their results, which raises questions about the reliability of the data.

💡Database

A database in the context of DNA ancestry testing refers to the collection of genetic data that companies use to compare and analyze an individual's DNA. The video discusses how the composition of these databases and the algorithms used to analyze the data can affect the accuracy of the results.

💡Ethnic Breakdown

An ethnic breakdown is a report provided by ancestry companies that details the estimated percentages of a person's ancestry from different regions or ethnic groups. The video questions the accuracy of these breakdowns, as different companies provide inconsistent results even for identical twins.

💡Recreational Science

Recreational science refers to the use of scientific tools or methods for leisure or entertainment purposes, rather than for rigorous research or practical applications. A health policy professor in the video suggests that DNA ancestry tests are more akin to recreational science, implying that they should be taken lightly and not be considered definitive proof of one's heritage.

💡Genetic Variation

Genetic variation refers to the differences in the genetic makeup between individuals. The video points out that even tiny genetic variations can lead to different ancestry estimates due to the formulas used by different companies, emphasizing the complexity and potential for error in DNA testing.

💡Marketing Messages

Marketing messages are the communications used by companies to promote their products or services. The video criticizes the marketing messages of DNA ancestry companies for potentially being misleading, as they imply a level of scientific certainty that may not be supported by the actual data and methods used.

Highlights

Identical twins took five DNA ancestry tests and received five different sets of results, raising questions about the accuracy of such tests.

DNA testing companies promise to reveal a person's ancestry and origins, but the results can vary significantly between companies.

Ancestry DNA, 23andMe, MyHeritage DNA, FamilyTree DNA, and Living DNA were the companies tested for consistency and accuracy.

Identical twins expected to receive identical results, but differences in their reported ancestries raised concerns about the tests' reliability.

Population geneticist Dr. Simone Gravel explains that DNA tests use statistical interpretation and models, which are not 100% accurate.

Ancestry companies analyze less than 1% of a person's 3 billion DNA parts, leading to statistical guesses rather than definitive answers.

Health policy professor Timothy Caulfield criticizes the ancestry business for selling a product that may not be scientifically accurate.

Caulfield describes DNA ancestry tests as 'recreational science' and advises not to take the results too seriously.

Living DNA's fine print admits that some of its results are guesses, highlighting the uncertainty in the provided ancestry percentages.

23andMe's confidence levels can be adjusted, with the default setting at 50%, meaning the company is only half sure of the reported ancestry.

The Yale team's analysis of the twins' DNA data from all five companies showed 99.6% to 99.7% agreement, yet the reported ancestry differed.

Different companies use different formulas and reference populations, leading to variations in the ancestry breakdowns they provide.

Ancestry DNA and Family Tree DNA were found to be more consistent in their results compared to other companies tested.

Experts suggest that the marketing of DNA ancestry tests may be misleading and not reflect the scientific limitations of the tests.

DNA results can change over time as companies update their databases and algorithms, a fact often not disclosed in advertising.

The DNA ancestry test industry is booming due to attractive marketing and human curiosity, despite questions about accuracy.

The message that DNA tests can reveal precise biological borders between populations is both scientifically incorrect and potentially socially harmful.

Humans share more than 99% of their DNA, emphasizing the importance of recognizing our similarities rather than differences.

Transcripts

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