DNA Genealogy

By ⁠Dr. Brandon Colby MD, a medical expert specializing in personalized preventive medicine and clinical genomics.

Discovering where we come from and who we may be related to has always been a source of curiosity and wonder for humans. Genealogy is the study of families and their lineage, and it has existed for thousands of years.

Back then, it was mostly used by noble families who wanted to ensure that their bloodline was pure, so that they would be considered worthy of whichever title or throne they were trying to claim. Now, genetic genealogy is used by millions of people throughout the world to discover their ancestors and learn more about their heritage.

Family Trees: Then and Now

Here’s a fun fact: in those times, it wasn’t uncommon for family trees to contain embellishments or outright lies. In fact, many noble lineages claimed to be descended from famous historical figures or even gods in order to appear more distinguished. Did you know that ancient English kings claimed to be descended from the Nordic god Odin? Yes — that Odin… Thor’s dad!

But thanks to modern DNA testing methods, it would now be impossible for anyone to claim a deity as their great-great-great-great-great-great-great-grandfather. However, genealogical DNA tests can still reveal many interesting facts about your ancestry and ethnicity.

What Is DNA Genealogy

A genealogical DNA test is — as its name suggests — a genetic test that analyzes specific sections of your DNA that are known to be correlated with your ancestry. ⁠Genetic genealogy is the combination of modern genetic testing with traditional genealogical research methods, which leads to more accurate and detailed results.1 

Our article ⁠What Is Genealogy explains what genealogy is and is a great place to start to learn more about this amazing field. 

DNA genealogy has made it possible for practically anyone to discover more about their ancestry and family history. Even if you don’t have access to an extensive paper trail (public records, journals, letters, certificates, among others) that details your ancestors’ lives through the years, DNA genealogy can help you understand your ancestral roots and determine where you come from.

Now, let’s talk a bit more about the benefits and possible drawbacks of DNA genealogy, how to understand your results, and which testing companies offer the most thorough analysis of your genetic information. 

Benefits of a Genealogical DNA Test

dna genealogy

There are many benefits to getting a genealogical DNA test, and they can achieve many different purposes.

Learn About Family History

Many people choose to take a genetic DNA test simply because they are curious about their family history, and they are interested in the possibility of finding distant family members. Traditional family history research relies on other genealogical methods, such as reviewing public records to find birth, marriage, and death certificates in order to gather the information needed to build a family tree.

But these methods are time-consuming, and many people don’t have easy access to the necessary sources. It’s not uncommon for genealogists to encounter “brick walls”2 during their family history research, which basically means that they reach a barrier in the research that can’t be overcome through traditional genealogy techniques.

These brick walls can happen due to many different reasons, such as lost contact between members of the same family, lack of public records detailing certain life events, adoption, migration, unexpected changes to the family name, among many others. Although some of them can be worked around eventually, there are also cases where they represent an insurmountable obstacle to the research.

Identify Unknown Relatives

But genetic DNA testing has made brick walls a lot easier to overcome. By simply uploading your DNA test results to different platforms, your genetic data will be compared to a DNA database to establish your ancestry and help identify your relatives.

Through a genetic DNA test, you won’t just be able to learn about past ancestors — you will also be able to connect with living relatives if they’re also present in the DNA database. From long-lost distant relatives to close first cousins, they could all be present in a DNA database.

These benefits can be particularly exciting for adoptees who wish to reconnect with their birth families, or people who may have lost contact with their extended families. So even if you can’t find sources or records to point you in the direction of your family, DNA testing will be able to solve the mystery for you.

In fact, DNA testing can go back in time to establish whether you’re related to ancient remains found in ruins. After all, all human beings are descended from Y-chromosomal Adam and mitochondrial Eve — our most recent common ancestors —, so it’s no wonder that genetic testing is able to travel so far back in time.

Ethnicity Estimates

DNA testing can also provide an ethnicity estimate, even if you don’t have clear-cut data on who your ancestors were. This can help you establish migration patterns to further understand your family history and the events that have shaped it over the centuries.

Warn of Possible Health Risks

Additionally, your ethnic background can shed light on possible health risks. Certain diseases are more common in specific ethnic groups — for example, people with African, African American, and Mediterranean ancestry are more likely to suffer from sickle cell disease. Likewise, Tay-Sachs disease is more common among people with Ashkenazi (eastern and central European) Jewish or French Canadian ancestry.3

Guide Medical Care

That means that your DNA results could help guide your medical care by pointing to the more likely diagnosis depending on your ancestry. This information can also be very useful for family planning, since it will allow you and your partner to have a clearer picture of the health risks that your children could inherit.

When discussing health risks and genetic testing, it’s important to remember that certain types of DNA tests could provide additional information regarding your health. The most common types of ancestry tests used to analyze your DNA data include:

  • Mitochondrial DNA (mtDNA) testing
  • Y-chromosome (Y-DNA) testing
  • Autosomal DNA (atDNA) testing

We’ll discuss each of these tests in more detail below — however, keep in mind that a different type of test called ⁠whole genome sequencing (WGS) can provide detailed ancestry data while also telling you everything you need to know about your health, and for a reasonable price. For that reason, WGS is quickly becoming a popular method for genetic testing.

Help with Law Enforcement

Genetic DNA testing can also be used in law enforcement, and genetic genealogists have helped solve crimes that had been a mystery for years. Comparing the DNA found at the scene with DNA samples found at crime scenes can lead to the discovery of partial matches belonging to relatives of the culprit, which gives detectives a clue as to who they need to investigate.

Genealogy Reports

Depending on ⁠the provider you choose to get your genealogical DNA test, you will receive an at-home testing kit that will allow you to collect a small DNA sample, which you will then have to ship back to the testing company. Within a few weeks, you’ll receive a report with your findings. 

Upload Raw DNA Data for Additional Reports

Sequencing.com offers genealogy reports, and it also gives you the opportunity to upload data provided by previous DNA tests to our platform. Since your testing results can vary depending on the reference database that is used to compare your results against, uploading your data to different platforms can lead to a wider range of information.

At Sequencing.com, you can access the ⁠DNA Ancestry and Genealogy Report, which provides a report that contains valuable insights about your ancient ancestors and genealogy. Its reference databases cover 6 continents, 22 subregions, and 97 countries, increasing the likelihood of finding the best matches for your DNA. 

This DNA App uses a technology called admixture analysis to calculate your geographical origins. Admixture analysis, also known as biogeographical ancestry analysis, detects the presence of DNA patterns that are characteristic of particular ethnic groups.4

It analyzes single nucleotide polymorphisms (SNPs), which are genetic variants that can be used to compare your DNA to the DNA of other individuals or populations. DNA genealogy works by annotating the results from these comparisons in order to establish similarities and differences.

Once the analysis is completed, you will receive a report that will include the ethnic percentages that make up your genetic ancestry, among other interesting insights surrounding your genealogy.

You could also access the Genetic Ancestry with Haplogroups Report. Haplogroups are a grouping of similar haplotypes — the alleles that you inherit together from one of your parents. This report compares your DNA information to 30 reference populations that cover populations from the entire world, and it includes:

  • Detailed ancestry composition
  • Admixture analysis
  • Maternal haplogroup
  • Paternal haplogroup (for males)
  • Haplogroup distribution
  • Historical figures that share your haplogroup

There are many other providers that offer DNA testing and ancestry reports, and it’s important to make sure that you research each one before using their services.

If you need help assessing the results of a genealogical DNA test, you can also use different resources, such as genealogical societies, the wiki provided by the International Society of Genetic Genealogy (ISOGG)5, databases such as GedMatch, among others.

You can also consult a healthcare professional, such as an online genetic counselor, to ask for guidance on how to interpret genealogy DNA results.

What You Need to Know About DNA Genealogy Accuracy

what you need to know about dna genealogy accuracy

As mentioned above, there are different types of ancestry DNA tests available. Your results could vary depending on the type of test that is used since each type of test performs a different kind of DNA analysis. 

  • Mitochondrial DNA (mtDNA) testing: this test analyzes the DNA contained in your mitochondria, which is transmitted through the maternal line. Thus, this type of test can be used to identify direct maternal ancestors. This type of test can be used by both males and females since all humans inherit at least one X chromosome from their mothers.6
  • Y-chromosome DNA (Y-DNA) testing: the Y-chromosome is exclusively inherited from father to son, and as a result, Y-DNA testing can only be performed in males. This test is used to establish a male line of genetic inheritance.7
  • Autosomal DNA (atDNA) testing: human DNA contains 22 pairs of chromosomes called autosomes, and a pair of sex chromosomes (XX for females, XY for males). Autosomal DNA testing analyzes the information contained in your 22 pairs of autosomes. This test determines DNA matches in centimorgans (cM), which is a unit used to measure genetic linkage.8

Each of these tests will study different branches of your genealogical tree with varying degrees of accuracy. So, for example, if you only get an mtDNA test, you won’t be receiving information regarding your biological father. Likewise, males who get a Y-DNA test won’t be testing the DNA from their maternal line.

Another factor that plays a big role in the accuracy of your results is the size of the databases that are compared against your sample. Different providers use different databases, which explains why your results may not look identical after analyzing your DNA through different services. Providers with the largest genealogy databases will understandably provide the most accurate results.

Genetic Genealogy Testing Companies

Thanks to the advent of the internet and modern DNA testing techniques, genealogical genealogy has become more popular than ever in recent years. There are many different DNA testing companies that exclusively offer ancestry tests. Some of the most popular include:

  • Sequencing.com
  • Ancestry.com or AncestryDNA
  • 23andMe
  • MyHeritage
  • FamilyTreeDNA
  • LivingDNA
  • HomeDNA
  • Geno DNA (by National Geographic)

Bear in mind that in most cases, testing companies only offer some combination of autosomal, Y-DNA, and mtDNA testing, rather than more complex sequencing analyses such as whole genome sequencing (WGS). At Sequencing.com, you can use the information from your WGS test to determine your deep ancestry and much more.

Interested in learning more about DNA testing options? Here’s a great comparison of the most popular DNA tests.

Free Genealogical DNA Test

In reality, there’s no such thing as a genealogical DNA test that’s 100 percent free. If a company offers “free DNA tests”, you’ll probably still have to end up paying in order to be able to access reports based on your results. Besides… would you really trust a provider that claims to offer free DNA testing with your genetic information? Yeah… neither would we!

Sequencing.com offers the Ultimate DNA Test and the Ultimate Genome Sequencing, which are both options that will allow you to access comprehensive genealogy results.

The Ultimate DNA Test uses microarray technology to analyze data on nearly 30 million variants in your genome — around 50 times more data than other popular providers, such as 23andMe and Ancestry.com. This is why it’s the best DNA test you can currently get.

If you want a more thorough analysis, the Ultimate Genome Sequencing provides WGS that tests 100 percent of your genome, obtaining genetic information from all 3 billion base pairs in your DNA. In addition to obtaining genealogic data, this test is also able to screen for rare genetic diseases, possible adverse effects to medications, nutrition, fitness, ⁠and much more.

Additionally, you can also ⁠upload your results from previous DNA tests to our platform for free. Through this service, you will be able to access ⁠reports on ancestry DNA and many other topics, such as health and wellness. Data can be imported from most of the most popular DNA testing companies, including:

  • 23andMe
  • Ancestry.com
  • MyHeritageDNA
  • Dante Labs
  • Nebula Genomics
  • DNALand
  • HomeDNA
  • LivingDNA
  • Vitagene
  • Genes for Good
  • Illumina
  • tellmeGen

Check out our Education Center to learn more about genetic genealogy, whole genome sequencing, and many other fascinating topics relating to genomics and DNA technologies.


About The Author

Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of Sequencing.com and the author of Outsmart Your Genes.

Dr. Colby has performed extensive research pertaining to how coronavirus causes infection. Dr. Colby describes his COVID-19-related research in the article Your DNA and Coronavirus: How To Know If You’re At Risk.

Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (⁠ACMG), an Associate of the American College of Preventive Medicine (⁠ACPM), and a member of the National Society of Genetic Counselors (⁠NSGC).


1
Tetushkin E. (2011). Genetika, 47(5), 581–596.
2
50 Best Genealogy Brick Wall Solutions (Part I). GiT Magazine. Retrieved January 23, 2021.
3
Why are some genetic conditions more common in particular ethnic groups? Medline Plus. Retrieved January 24, 2021.
4
Admixture analyses. International Society of Genetic Genealogy Wiki. Retrieved January 23, 2021.
5
International Society of Genetic Genealogy. Retrieved on January 23, 2021.
6
Mitochondrial DNA. Medline Plus. Retrieved January 24, 2021.
7
Y chromosome. Medline Plus. Retrieved January 23, 2021.
8
Autosomal DNA. International Society of Genetic Genealogy Wiki. Retrieved January 24, 2021.

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