What is the geographic and historic origin of my mitochondrial DNA (mtDNA) haplogroup?

The following descriptions provide brief overviews of each main mtDNA haplogroup’s origin and geographic distribution. Haplogroup A Haplogroup A is found in eastern Eurasia and throughout the Americas. This haplogroup was present in the populations […]

How do I know which of my heteroplasmic values is ancestral (original) and which is derived (new)?

To find which version of a heteroplasmic mitochondrial DNA (mtDNA) result is original and which is newer, you need to test other descendants of your direct maternal ancestor. The non-heteroplasmic variant that is most common […]

From which “Daughter of Eve” do I descend?

The Daughters of Eve are named after some of the major haplogroups, but the names are arbitrary. The names usually begin with the same letter as the haplogroup name. We identify the haplogroup itself.

How do I tell how closely I am related to a mitochondrial DNA (mtDNA) match?

The closeness of a mitochondrial DNA (mtDNA) match depends on the matching level. Matches at higher levels are more likely to be recent. The table below shows the expected time to a common ancestor with […]

How do I find the genealogical connection with my mtDNA match?

The only way to find a connection with your match is by comparing your genealogies. In many cultures, women changed names with marriage. Therefore, it is important to compare geographic locations alongside genealogical information and surnames.

Are there exceptions to the alphanumeric naming of mitochondrial haplogroups?

Yes. There are two exceptions to the alphanumeric naming of mitochondrial haplogroups. The first is the use of a zero (0) in the name to indicate that a branch is being inserted between what was a […]

Will my mitochondrial DNA (mtDNA) results show me admixture percentages for ancestry from different lines?

No, because mitochondrial DNA (mtDNA) is inherited exclusively from your direct maternal line, it does not show admixture from your other lines. That is, you received your mitochondrial DNA from your mother, who got it […]

How common is mtDNA heteroplasmy?

All mitochondrial DNA (mtDNA) mutations go through a state of heteroplasmy. The frequency of heteroplasmy is then equal to or greater than mtDNA mutation rates. Note that population geneticists usually calculate mutation rates using those […]

How is mtDNA heteroplasmy inherited?

In each generation, it is possible for the child to inherit the heteroplasmic genome, only the ancestral genome, or only the descendant genome. For each generation, if the mother has a heteroplasmy, each of her […]

How do mitochondrial mutations occur?

Every human cell contains hundreds of mitochondria. Each mitochondrion in a cell contains multiple copies of its own DNA (mtDNA). A new mitochondrial mutation occurs in only one copy of the mtDNA in one mitochondria […]

Where can I share information with others who have mtDNA tested?

There is an mtDNA section in FamilyTreeDNA’s Forums.

How do I use mtDNA (mitochondrial DNA) to help with my recent genealogy?

To find connections in recent times, it is necessary to find and test multiple people who have suspected shared ancestry. You can do this by careful examination of traditional genealogical records. Making connections with people […]

Are all of a mother’s new mitochondrial DNA (mtDNA) mutations inherited by children?

No. Mothers only pass on those mitochondrial DNA (mtDNA) mutations they inherited from their mothers and new mutations that occur in their eggs. Mutations that occur elsewhere are not inherited.

Do all direct maternal (mitochondrial DNA) lineages trace to Africa?

Yes so far, all direct maternal (mitochondrial DNA) lineages of women alive today trace back to a common ancestor who lived in Africa 100,000 to 180,000 years ago. Further back, the mitochondrial lines of Homo […]

How does the formation of the human egg cell change the frequency of an mtDNA heteroplasmic mutation?

At one point during the process by which the egg cell is produced (oogenesis), the number of mitochondria present in the cell is dramatically reduced from hundreds to perhaps as few as ten. These copies […]

How are mtDNA haplogroups named?

In general, scientists name mitochondrial DNA (mtDNA) haplogroups according to their major branch with a capital letter. They then name subclades (branches) with alternating numbers and letters: H, H1, H1a, H1a1, etc. H H1 H1a […]

As a genealogist, do I really need to understand all of this complex information about mitochondrial DNA (mtDNA) in order to use it for my research?

No. As a genealogist, you may focus on a few basic rules. These will allow you to use mtDNA (mitochondrial DNA) to assist with your traditional genealogical research on maternal lineages. It is best if […]

How many generations back does mitochondrial DNA (mtDNA) testing trace?

Mitochondrial DNA (mtDNA) testing covers both recent and distant generations. Matching on HVR1 means that you have a 50% chance of sharing a common maternal ancestor within the last fifty-two generations. That is about 1,300 […]

How do I know if I have an mtDNA (mitochondrial DNA) heteroplasmy? What is the nomenclature?

You will know that one of your mutations or differences from the RSRS is a heteroplasmy by its letter codes. Symbol Meaning Symbol Meaning U U (Uracil) S C or G M A or C […]

Are some mitochondrial DNA (mtDNA) mutations more common than others are?

We see some mitochondrial DNA mutations more often than others. One mutation which we find often in a number of different haplogroups is C16311T in the HVR1 result. This is a base pair in the […]

What is a mitochondrial DNA (mtDNA) deletion? What is the nomenclature for displaying them?

Deletions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have not been copied. The sequence will not have a result for that place. When a […]

What is an mtDNA insertion? What is the nomenclature for displaying them?

Insertions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have been added to the DNA sequence. In in the example below, the sequence has an […]

What is an mtDNA transversion? What is the nomenclature for displaying them?

Transversions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have changed value. Transversions are where a purine has mutated to a pyrimidine or where a […]

What is an mtDNA transition? What is the nomenclature for displaying them?

Transitions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have changed value. Transitions are where a purine has mutated to the complimentary purine (A <-> […]

Where are apostrophes (‘) used in mtDNA haplogroup names?

Apostrophes are used to create a common branch between two well-established branch points in the tree. One example is M1’20’51. It is the common parent of the M1, M20, and M51 branches. M1’20’51 M1 M20 […]

Where are zeros (0)s used in mitochondrial haplogroup names?

Zeros are used when a new branch point needs to be inserted above a well-established branch point on the mitochondrial tree. One of the best-known examples of this is the insertion of R0 between the […]

Why do we inherit only our maternal mitochondria?

Male sperm contain paternal mitochondria. After cell fertilization, the paternal mitochondria are eliminated from the newly formed zygote.

Is the mitochondrial DNA (mtDNA) genome completely independent of the nuclear cell genome?

No, it is not. Over time, some of the genetic code from the mitochondrial genome migrates to the nuclear cell genome. However, enough mitochondrial genetic code remains independently inherited to make mtDNA highly useful for both […]

What are mitochondria?

Mitochondria are specialized subunits (organelle) within cells. In humans, mitochondria are responsible for cell respiration and for producing energy. They evolve into their current state from separate organisms that form a mutually beneficial (symbiotic) relationship […]

Why do I have a lot of mitochondrial DNA (mtDNA) test matches?

Some mitochondrial DNA (mtDNA) haplotypes show a high number of matches. There are two possible explanations for this. Many people with the same results as your ancestors lived thousands or tens of thousands of years […]

Why don’t I have HVR1 and HVR2 (HVR1,HVR2) combined matches?

If you do not have HVR1 matches, you will not have HVR1 and HVR2 (HVR1,HVR2) combined matches. This is because anyone who is an HVR1,HVR2 match has the same HVR1 result as you. They are […]

Why don’t I have HVR1 matches?

You are the first person with your particular HVR1 sequence to be in our database. This can mean that your result is relatively rare and that, as a result, few people have it. It can […]

Is my mitochondrial DNA (mtDNA) mutation medical? Is mitochondrial heteroplasmy medical?

Family Tree DNA offers mitochondrial DNA (mtDNA) full sequence tests strictly for genealogy and personal ancestry information. Therefore, we do not examine or discuss medical implications of any person’s mtDNA full sequence. In general, the […]

What is a mitochondrial DNA (mtDNA) heteroplasmy?

Heteroplasmy is the presence of more than one type of a genome (in this context, mitochondrial DNA) within a cell or organism. Put another way, a heteroplasmy is where more than one result exists for […]

Why are some of my mitochondrial DNA (mtDNA) mutations found on other branches of the tree?

Some mitochondrial DNA (mtDNA) mutations are found throughout the mtDNA tree. This is because the same mutation has happened dozens or hundreds of times in human history.

What are mitochondrial DNA (mtDNA) mutations?

Mutations are changes to your DNA code. They are natural copying errors. One analogy is to think of a copy machine that is making many copies of a page. Occasionally the printer will make a mistake, for […]

What do my differences from the RSRS (Reconstructed Sapiens Reference Sequence) mean?

When we test mitochondrial DNA (mtDNA), your results are a list of the four bases that make up DNA, represented by the first letter of their name (Adenine, Thymine, Cytosine, and Guanine). Your results are then compared to […]

What is the Reconstructed Sapiens Reference Sequence (RSRS)?

The Reconstructed Sapiens Reference Sequence (RSRS) is a mitochondrial DNA (mtDNA) reference sequence that uses both a global sampling of modern human samples and samples from ancient hominids. It was introduced in early 2012 as […]

What version of the mtDNA Tree Does FamilyTreeDNA use?

We use the V14 version of Phylotree published in Behar et al. 2012, A “copernican” reassessment of the human mitochondrial DNA tree from its root. We plan to upgrade to the V15 version as part of […]

What are mtDNA macrohaplogroups? What are supergroups? Are they the same?

Macrohaplogroups (sometimes called supergroups) are the foundation for a number of other haplogroups. They represent older shared ancestors on the maternal tree. Macrohaplogroups link together many of the more common haplogroups that are found today. […]