What Is A Genealogy DNA Test?

DNA testing has recently become popular and mainstream due mainly to reduced costs and the continual Ancestry adverts you see on TV. But what is a genealogy DNA test and how can it help you with your family history research?What Is A Genealogy DNA Test?

Well, read on and I will explain it all to you.

When did DNA testing first start?

DNA testing became publicized in the late 1990s due to several cases that were brought to the public eye.

These cases used DNA to test whether there was any family connection between people that were long deceased.

And so everyday people became aware of this type of testing.

Who supplied the first tests?

The first company to offer genealogy DNA testing was FamilyTreeDNA. They offered DNA testing in May 2000.

The only testing though at that time that they could offer was to test male to male inheritance. This is referred to as Y-chromosome testing, (more on this later).

From then on the field of genealogy DNA testing has widened to include more tests.

And with the advancements in technology it has become more affordable for the everyday public.

So, you too can get tested for under $100!

Please watch this!

The following short video from AncestryDNA can show you the potential of taking the test.

Credit:   AncestryDNA

Coupled with connecting with billions genealogical records you can really discover your family history.

Reasons to do a DNA test!

There are a number of reasons why you would want to do a DNA test.

These may vary from a paternity test to confirm a child’s father, forensic testing or to checking an unborn fetus for health problems.

And, also the main reason why you are thinking about a DNA test, and why you are here, is because you are interested in your genealogy!

Conducting a genealogy DNA test can help you to break down any brick walls that you may have encountered during your research.

If you have ever struggled to find a connection or want to know what step to next step then this type of testing can help you.

Please note: It must be pointed out that DNA testing is not used to determine genetic diseases or disorders.

This type of testing is only to provide genealogical information.

Check Out The Best DNA Testing Kits

What Is DNA?

To give its full title, DNA is short for deoxyribonucleic acid. It is described as a self-replicating material and can be found in all living organisms.

What Is DNA Markers?

DNA contains genetic information that can tell us what color eyes we have, or what color hair, or our skin color as well.

It’s inside all of us!

Nearly every cell within our human body has this same structure, this same DNA.

Nearly all of this information is contained within the cell nucleus. Some though is stored within mitochondria, (more on this later).

DNA therefore can give us genetic information about ourselves.

As we inherit characteristics from our parents it can also tell us about our family and therefore our ancestors.

What I find surprising about DNA is that 99.9% of this material is identical in all humans.

It is only 0.1 that differs and thus sets us apart from everybody else.

On Your Marks!

This variance in DNA sequences are called genetic markers. These markers are then used by scientists to perform tests and to see the difference between people.

By testing these markers we can also see how closely two people are related.

(As a side note identical twins are, as the name suggests, identical and as such they have identical markers).

The trouble though with this testing is to know where to look. There are billions of code that we need to sift through in order to find these markers.

I won’t go any further with the details about DNA as it can get pretty complicated, and that is not the aim of this post.

So, next I will discuss the different types of DNA testing that is available to you and which companies can provide this form of genealogy research.

What Types Of DNA Testing Are There?

In the beginning there were only two forms of DNA testing that were available. With the advancement of technology and tools genealogy testing can now be broken down into four types.

Each of these tests can help with a different aspect of your genealogical research.

The 4 types of DNA testing:

Each of these tests look at spots or markers in our DNA that change slowly over time. These markers are inherited from our parents.

People who are closely related will have the same DNA signature. Obviously unrelated people will have a different signature.

Commercial DNA testing companies such as 23andMe, AncestryDNA and FamilyTreeDNA provide a swab or spit kit.

There are also centers where you can visit where you can do this test.

You can expect results for these to take between 6 to 8 weeks.

How Many Chromosomes Do We Have?

Before I explain the different types of genealogy DNA testing I will first briefly describe what DNA and chromosomes are.

We each carry 23 pairs of chromosomes, where a chromosome is a thread-like structure that carries genetic information in the form of genes.

How Many Chromosomes Do We Have

So, our DNA is a specific set of instructions that make up each and every one of us.

Within each of these pairs we carry one chromosome from our father, and the other from our mother.

The first 22 pairs are called autosomes, and this is information that has been passed down from generation to generation.

The 23rd pair is known as the sex chromosome, and this is what makes us a male or female.

Y-chromosome (yDNA)

This DNA test looks at the Y chromosome which is passed down the paternal line from father to son. This test is only suitable for males.

Father and Son

As a result of this female genealogists will have to ask their father, brother, uncle or male cousins to do the test.

Results are compared for this chromosome and checked against males to see if there is a match.

They are also checked to see if they are related in a genealogical timeframe.

From this test the haplogroup is also obtained. The haplogroup defines deep ancestry and can be broken down into ethnicity such as European, Asian, and African.

There are though other haplogroup groups and interest projects.

Mitochondrial DNA (mtDNA)

The mitochondrial DNA is passed on from the mother to her sons and daughters. However, although males carry this information only females will pass it on.

Mitochondrial DNA

Through this test you can also obtain the haplogroup to check for deep ancestry.

Mutations are compared to see if anyone shares a common ancestor in a genealogical timeframe.

As this tests the maternal line your ancestors’ surnames will change with every generation.

With this test it is far more difficult to make connections, so you may not be able to make sense of the results and benefit from it fully.

Autosomal DNA (atDNA)

This tests the 22 pairs of autosomes that come from both parents. The three big companies 23andMe, AncestryDNA and FamilyTreeDNA all offer this testing.

Special Family Days

They can test over 700,000 markers and provide you with a list of cousins from all of your branches. Autosomal DNA testing can also determine common ancestors.

Information is filtered as it is passed down to you and so some markers may not be present in your DNA.

You may even receive varying results from different companies.

This is basically because they each have their own distinct way to class your DNA.

The autosomal test will give you results for only 4 to 5 generations back.

So, before you decide to take this type of DNA test it is best to first consider how useful the results will be for you.

X-chromosome (xDNA)

This test is different from the mitchondrial DNA test that looks at the maternal line. Men have an X and Y chromosome, whereas women have two X chromosomes.

Incidentally, the Y chromosome is passed on from the father.


Men will inherit one X chromosome which is from their mother. Women however will receive two X chromosomes, coming from both parents.

The inheritance path for X chromosomes is therefore different for both men and women as not all ancestors will contribute to this X chromosome.

As this is a new type of testing the three main genealogy DNA companies do not offer this.

What Do The Genealogy DNA Companies Offer?

FamilyTreeDNA is the only company to offer full genealogy DNA testing covering the first three types.

23andMe do offer atDNA testing and also very low predictions concerning yDNA and mtDNA.

The third most popular company AncestryDNA only offer atDNA testing.

There is at present only one company that offers the fourth type of testing and they are deCODE genetics.

These companies do operate in the US but they can ship your tests and results to any country. Obviously shipping will take longer if you live outside the US.

There are plans by these companies to operate in the UK and Australia. This will save you both money and time waiting for tests and results.

Please note: I will be covering the three main genealogy DNA companies in future posts.

Your DNA Data and Privacy!

One concern that you may have before you decide to take this next step is the privacy of your DNA data. After all it is essentially your information and who knows what can be done with it in the wrong hands.

All of the DNA testing companies that I have reviewed on this site have stated and assured that your DNA data is not shared with any third party.

I would like to share with you an article by Victoria Mcintosh entitled DNA testing kits: What are the privacy risks.

My Final Thoughts!

Genealogy DNA testing has provided many family historian with the clues they need to get passed brick walls that they may have encountered during their research.

It is also enabled them to connect with distant cousins who they did not even know existed before they even carried out this type of testing.

However, before you do conduct this type of testing I would suggest that you have researched your family tree for a while.

If you do get stuck along the way then why not use DNA testing in order to pass that hurdle.

Finding distant relatives can also be a bonus to you as they can share with you information that they know about their side of the family.

Resources to help your DNA testing!

There are a few DNA genealogy books that I recommend that will help you with this type of research.

These books will cover what types of testing is available to you in more detail. I have only scratched the surface here as I wanted to be brief and point in you the right direction for more guidance.

These books can also help you to fathom the results that you will get back.

The results returned to you may possibly baffle you so it is well worth having a guidebook that will help you to interpret these results and ultimately help you go further with your research.

Did you know that you can improve your genes through meditation?

Well, to find out why not visit Medit Sounds for more information.

Medit Sounds

Thank You and Please Leave A Comment

I hope you enjoyed this guide to what is a genealogy DNA test. If you have any questions or comments then please leave a comment below.

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