Autosomal DNA, Y-DNA and mitochondrial DNA tests: what are they and what are their differences?

For those who are regular readers here at Living DNA, you may have come across terms like Y-DNA and mitochondrial DNA before. However, you might be just as foggy on the terms and their differences as a first-time reader. So, welcome, and let’s begin.

The world of genealogy is equal parts fascinating, complicated, and scientific. Whilst we do our best to keep our content somewhere around the surface level so that all interested parties can enjoy what we have to say, there are times that some jargon requires further explanation. This article is one of those times.

Firstly, What are Haplogroups?

Before we dive into Autosomal DNA, Y-DNA, and Mitochondrial DNA tests, it’s best that we look into haplogroups.

To keep things simple, a haplogroup is a genetic population group consisting of people who share a common ancestor on either the paternal or maternal line. Some haplogroups are commonly associated with groups like the Celts, Vikings, or Franks, however, belonging to a certain haplogroup does not guarantee that your ancestors belonged to that ancestral group.

As you will learn more about in this piece, Y-DNA passes from father to son, and mtDNA passes from mothers to both sons and daughters, with haplogroups following both lines. Once upon a time, there would have been only one haplogroup, somewhere in Africa, however, each mutation over thousands of years has resulted in new haplogroups being formed.

Genealogists are able to take different information from the paternal lines and the maternal lines, though this information correlates very accurately.

Haplogroups are typically given letter-based names. For example, Haplogroup H is found in around 40% of Europeans, L1, L2, and L3 are most prevalent in Africa, and B, C, D, M, and Y are found in South and East Asian countries with the most regularity.

For more information, read our extensive guide on Haplogroups.

What is Autosomal DNA testing?

This is the most common and popular DNA test on the market, and it’s one we offer as standard in testing packages to our valued clients here at Living DNA. For this reason, it has the largest database of information, is constantly being added to, and can offer more DNA-based data to clients than any other form of testing. It is offered to both men and women, unlike the other tests, as you’ll come to learn.

Whereas other types of testing look at either the maternal DNA or the paternal DNA, autosomal looks at the autosomes that we inherit from both parents. “What is an autosome?” you may be asking, well, humans have 46 chromosomes, but only 2 of those (X & Y) are used to define sex. Other chromosomes carry different kinds of data, and autosomes are any of the other 22 pairs of chromosomes that carry our DNA sequences and genes.

22 autosomes come from mum. 22 autosomes come from dad. Through a process called recombination, the DNA is all shuffled up and is actually a mixture of information from our four grandparents.

Autosomal testing means finding the 22 autosomes that carry the dominant information about your heritage and cross-referencing it with the data we have available.

The autosomal test results provide you with your genetic ancestry going back approximately 10 generations. Your test gives you a clear percentage breakdown across the population groups that your genetic code has been compared against.

What is Y-DNA Testing?

Whereas Autosomal testing looks at both the maternal and paternal data, Y-DNA looks at only the Y chromosome, which contains the paternal data. This is because women don’t have a Y chromosome. The Y Chromosome and corresponding DNA information (Y-DNA) passes through the paternal line, from father to son. By taking a Y-DNA test, you will only find ancestral information about your paternal line, as opposed to both paternal and maternal.

As a result of this chromosomal fact, Y-DNA testing is only performed on DNA samples collected from men, as it will not be able to tell women anything about their paternal haplogroups. Women could find out what their results would be by having their full brother, father, uncle, or grandfather take a DNA ancestry test on their behalf.

Your Y haplogroup is the code that describes a group of people that share a common paternal ancestor that lived up to tens of thousands of years ago.

What’s great about Living DNA is that when males purchase our ancestry testing services, we perform the Y-DNA test in addition to the Autosomal test, to give the most full report possible.

And finally…

What is Mitochondrial DNA Testing?

Mitochondrial DNA is the motherly equivalent to Y-DNA testing. Maternal haplogroups, rather than being discovered by testing the X chromosomes, are tested based on Mitochondrial DNA (mtDNA). What makes mtDNA unique is that it is found outside of the cell nucleus, which is fortunate for genealogists, as it means it hasn’t mixed with other DNA data.

Hold up, what is mitochondrial DNA? This is a chromosome found inside every cell inside your body, and it is something you inherit from your mother regardless of your gender.

The mtDNA reveals ancestral information about the maternal line, so a female, her mother, sister, aunt, or grandmother will all reveal the same results. On top of that, a brother, father, uncle, or grandfather can take an mtDNA test too, because unlike the Y chromosome, mtDNA is found in both males and females.

With the collected sample, genealogists can track the maternal haplogroup back until a single mutation is discovered, with this revealing significant information about your ancestral past. Your mitochondrial haplogroup is the code that describes a group of people that share a common maternal ancestor that lived up to tens of thousands of years ago.

Here at living DNA, we offer a basic mitochondrial haplogroup test within our ancestry DNA package.

What does all of this mean for your Living DNA journey?

Well, it means that not only do you get access to the Autosomal DNA test, which is the most popular on the market, but you also get exposure to other tests too! For men, all three tests are applied to your mouth swab sample, whereas women’s DNA will be tested on both Autosomal DNA and mtDNA. What incredible value!