What are haplogroups?

Liz Wood, AlphaBiolabs

By Liz Wood, Health Testing Specialist at at AlphaBiolabs
Last reviewed: 05/07/2024

Ancestry testing is a fascinating way to discover your ancestral roots. The results can tell you about the journey your ancestors took tens of thousands of years ago and give you some insight into the lives they may have led.

In this article, we discuss paternal and maternal haplogroups, the differences between these haplogroups, how they are inherited, and how you can find out your paternal or maternal ancestral lineage.

What are haplogroups?

The International Society of Genetic Genealogy states that a haplogroup is a group of people within a genetic population that share a common paternal or maternal ancestor.

One haplogroup will consist of similar haplotypes. A haplotype is a group of DNA markers on a chromosome which tend to be inherited together.

Since paternal and maternal haplogroups are inherited, your ancestry can be traced back over thousands of years.

The Y chromosome and mitochondrial most recent common ancestor (MRCA) were haplogroups A and L respectively. As much time passed, changes in the DNA – specifically in the Y chromosome and mitochondrial DNA – gave rise to new haplogroups.

These changes are often referred to as “defining mutations”. They are the mutations that caused a new “branch” or subclade of a haplogroup to form, or even cause a new haplogroup to emerge.

Migration and population bottlenecks caused new and different haplogroups to spread across the world. As people settled in a new area and had children, they passed their Y chromosome or mitochondrial DNA on to their children, and as time went on, certain haplogroups became more frequent in certain areas.

Our haplogroups can therefore tell us a story about when our ancestors existed, where they may have migrated to and how they might have lived.

What are the differences between maternal and paternal haplogroups?

Ancestral lineage can be analysed by testing for either the maternal or paternal haplogroup.

The differences between the two haplogroups lies in how they are inherited. Our DNA is made up from the DNA we inherited from our parents, with 50% inherited from our mother, and 50% from our father.

There are two exceptions to this rule: mitochondrial DNA (mtDNA) and the Y chromosome.

Mitochondria are structures that are found within our cells that make chemical energy, which our bodies then use to function. These mitochondria are also special because they have their own DNA, which is exclusively passed down from mother to child. By analysing your mtDNA, your maternal lineage can be traced back thousands of years to where your maternal line originated.

The Y chromosome is a sex chromosome that only males have. If you are male, your Y chromosome is inherited directly from your father, who inherited it from his father, and so on.

The Y chromosome remains largely unchanged between generations so, by analysing the markers on your Y chromosome, it is possible to trace your paternal line back thousands of years to see where your ancestral line begins.

What are maternal haplogroups?

Maternal haplogroups are differences in human mtDNA. Over time, defining mutations occurred in the mtDNA, forming new haplogroups and new branches within these haplogroups.

The different mitochondrial haplogroups represent different points of the mitochondrial phylogenetic tree.

Since mtDNA is passed exclusively from mother to child, we can find out what maternal lineage, or haplogroup, a person has.

Haplogroup H

Haplogroup H is by far the most common and diverse maternal lineage found in Europe, accounting for roughly 40% of Europeans.

It is believed that haplogroup H originated in Southwest Asia approximately 25,000 years ago, expanding into Europe before the Last Glacial Maximum, where it is now the dominant mitochondrial haplogroup.

This haplogroup is also one of the “youngest” mitochondrial haplogroups. For comparison, “Mitochondrial Eve” is believed to have existed 100,000 – 200,000 years ago! 

H1 and H3 are the most common subclades of haplogroup H in Europe and can be found at high frequency in the UK, Spain, Portugal, France, and the north of Africa.

Haplogroup U

Maternal lineage haplogroup U is approximately 15,000 years older than haplogroup H. It is less frequently found in populations compared to haplogroup H. It likely originated in Southwest Asia.

Nowadays, haplogroup U can be found across much of the world, including Europe, Africa and Asia. There is some evidence to suggest that haplogroup U used to be the dominant mitochondrial haplogroup prior to the spread of agriculture from the Near East into Europe.

Haplogroup U4 is found at a low frequency (2-6%) across most of Europe. It likely originated about the same time as haplogroup H, some 25,000 years ago. Haplogroup U4 is often found amongst the Y chromosomal haplogroups R1a and R1b.

Haplogroup U5 is more common than U4 (5-12%) throughout Europe and is most common in Northern Europe. This haplogroup likely originated somewhere between 30,000 and 50,000 years ago and is most commonly found in places with high frequencies of the Y chromosomal haplogroups I1, I2 and R1a.

Haplogroup J

Mitochondrial haplogroup J is believed to have emerged roughly 45,000 years ago in the Near East or the Caucasus. It is found relatively frequently and evenly across Europe.

The subclade J1c is approximately 16,500 years old. J1c is quite rare in the Middle East today, suggesting that hunter-gatherers of this lineage diffused into Europe during Neolithic times. Now, haplogroup J1c is the most commonly found subclade of haplogroup J in Europe, and one study found that it is the most frequent maternal lineage amongst Scandinavians.

J2 is older than the J1 lineage, likely originating approximately 33,000 years ago in Western Iran. Nowadays, J2 is most found in the Middle East and some southern parts of Europe. It is also found in relatively low frequency in North Africa.

Haplogroup T

A close relative of haplogroup J, haplogroup T likely originated in the East Mediterranean region about 25,000-29,000 years ago. It is present at relatively low frequencies across Central and Western Asia as well as Europe. Approximately 10% of people who are natives of Europe belong to the maternal haplogroup T.

Haplogroup T2 is a subclade of haplogroup T. It is more common than its sister clade T1, ranging from about 1-10% in frequency across Europe at present day. Maternal haplogroup T2 is approximately 21,000 years in age and may have originated in the Near East.

Haplogroup K

Haplogroup K likely originated in West Asia between 22,000 and 30,000 years ago. It is found in higher frequencies in places such as Cyprus and Georgia but is also commonly found in some parts of Northwest Europe, like Ireland, Belgium and the Netherlands.

A branch of haplogroup K, K1, may have emerged roughly 20,000 years ago. It is a very diverse and widespread subclade, found across most of the European continent.

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What are paternal haplogroups?

Paternal haplogroups are specific differences in the Y chromosome of men. The Y chromosome is a sex chromosome inherited from your father.

The Y chromosome remains largely unchanged across generations within the same family. That means that if you are male, your Y chromosome is the same as the Y chromosome of your paternal male family members (e.g. paternal grandfather, brother, uncle etc.).

Specific defining mutations (changes) to the Y-DNA caused new haplogroups to form throughout the years. These haplogroups are defined by the specific single nucleotide polymorphisms (SNPs) that are unique to each haplogroup.

It is possible to determine the approximate location and time of origin for a haplogroup by assessing ancient evidence, molecular clocks, and present-day population genetics. By doing this, we can see when these paternal haplogroups may have formed and the migration patterns our ancestors may have taken.

Haplogroup R

Haplogroup R is found in high frequency across many parts of the world. It is thought to have originated in North Asia about 25,000 years ago; a comparatively young haplogroup age when compared to older lineages such as haplogroup E.

The subclade R1b is the most common Y-chromosome haplogroup in Western Europe, which likely originated in Western Asia, North Eurasia or Eastern Europe around 16,000 years ago.

The dominant branch of R1b is R-M269 (sometimes called R1b-M269). In some parts of Ireland and Wales, the frequency of R-M269 can be as high as 90% of the population and is very commonly found in the rest of the UK population.

The subclade R-L21 (also known as R1b-L21) is a descendant of R-M269, potentially originating sometime in the Middle Bronze Age in Western Europe. It is a very common patrilineal haplogroup in the UK. A decline in frequency is observed as you travel further east out of the UK. While R-L21 is still found in populations in countries like Norway, Belgium, and the Netherlands, it is observed far less frequently than within the UK.

Haplogroup I

Haplogroup I is a relatively old haplogroup, originating roughly 30,000 years ago. It is almost completely absent in areas outside of Europe, which suggests that it originated in Europe.

One of the major branches of haplogroup I is haplogroup I1. It originated some time after the emergence of basal haplogroup I. Much like its ancestral haplogroup, I1 seemed to be present only in ancient European samples. It is believed that I1 may have originated in Scandinavia, partly because Scandinavia has the highest frequency of the I1 haplogroup.

The other major branch of the I haplogroup is I2, which may have originated during the Late Palaeolithic period. It is generally agreed that I2 emerged in Western Europe. However, a more precise location is difficult to determine, as early generations of haplogroup I2 men were likely nomadic hunter-gatherers.

Nowadays, the I1 haplogroup is most frequently found in Scandinavia and Finland, decreasing in frequency as you move further south. Haplogroup I2 is a major lineage in Slavic countries, where it can be found in large numbers in Bosnia, Croatia, Serbia, Romania and Sardinia.

Haplogroup E

Haplogroup E is a very old paternal lineage that emerged in East Africa approximately 70,000 years ago and remains the most common haplogroup in Africa.

Outside of Africa, haplogroup E is also present in populations in the Near East and some parts of Europe, although at lower frequencies than those observed within Africa.

One of the most common subclades of haplogroup E is E1b1b. You might also see this haplogroup referred to as E-M215 or E-M35 in reference to the M215 or M35 defining mutations. This haplogroup may have emerged roughly 26,000 years ago in the Horn of Africa, before dispersing into the North of Africa and the Near East.

Nowadays, the E1b1b haplogroup is found in very high numbers in North Africa, in countries such as Morocco, Somalia, Ethiopia, Algeria and Tunisia, and is also present in some European populations, although at lower frequencies.

In fact, it’s believed that E1b1b did not arrive in Europe until approximately 10,000 years ago. Kosovo, Montenegro, Bulgaria and Greece have the highest frequencies of E1b1b outside of Africa, and evidence suggests that around 20% of Ashkenazi Jews belong to the E1b1b haplogroup.

Haplogroup J

Paternal haplogroup J likely originated in Western Asia, perhaps some 40,000 years ago. The people of this haplogroup migrated, causing the spread of haplogroup J into the Middle East, the North and Horn of Africa, the Caucasus and central Europe.

It’s not fully understood when exactly the two major branches of haplogroup J, J1 and J2, emerged. However, some evidence suggests that J1 and J2 have been distinct from each other for about 30,000 years.

Today, J1 can be found at high frequencies in parts of Iraq and Iran that are near the Zagros Mountains, as well as Yemen, Saudi Arabia and Qatar. People belonging to the J2 paternal haplogroup are most likely to be found in Cyprus, Crete, Lebanon, Greece and Turkey, as well as some parts of Iran and Italy.

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How can I find out my haplogroup?

You can order a maternal or paternal lineage ancestry test direct from our accredited laboratory.

With only a simple cheek (buccal) swab sample required, these tests can give you an insight into the journey your ancestors took thousands of years ago, as well as giving you an idea of where your ancestral line may have originated.

Our Maternal Lineage Ancestry Test is available for both men and women, as each person inherits mitochondrial DNA from their mother.

The Paternal Lineage Ancestry Test can only be taken by males, as the test analyses DNA markers on the Y chromosome, which is only found in males.

However, if you are a woman who would like to find out more about the paternal lineage of your family, you can ask a close male relative (e.g. father, brother, father’s brother etc) if they would like to take the Paternal Lineage Test.  

For more information about our ancestry testing, call our friendly, knowledgeable Customer Services team on 01 402 9466 or email info@alphabiolabs.ie.

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Liz Wood, AlphaBiolabs

Liz Wood

Health Testing Specialist at at AlphaBiolabs

Liz joined AlphaBiolabs in 2021, where she holds the role of Health Testing Specialist.

As well as overseeing a range of health tests, she is also the lead on several validation projects for the company’s latest health test offerings.

During her time at AlphaBiolabs, Liz has played an active role in the validation of the company’s Genetic Lactose Intolerance Test and Genetic Coeliac Disease Test.

An advocate for preventative healthcare, Liz’s main scientific interests centre around human disease and reproductive health. Her qualifications include a BSc in Biology and an MSc in Biology of Health and Disease.