mtDNA haplogroup H is one of the haplogroups you may find in your DNA, specifically your mtDNA. Jayne provides us with an overview of mtDNA haplogroup H and what it can tell you about your ancestry.
Perhaps you have been poring over your DNA test results from 23andMe and you have come across an unfamiliar set of words: haplogroup H. You’re in the right place to learn more about what this means for your family origins.
Before we focus specifically on mtDNA haplogroup H, let’s brush up on some basics:
- Haplogroups describe very deep ancestry, often tens of thousands of years ago.
- Haplogroups branch over time as DNA mutations occur naturally. (Here’s a deep dive into how that happens.)
- People who share the same haplogroup can often trace their ancestry to a similar geography or ethnicity, but having the same haplogroup is not in itself evidence of more recent shared ancestry, like close family or cousinship. That said, sometimes fine-detail sub-divided haplogroups can be very specific to a certain geography and more recent lineage, so this can be very lucky and useful if your DNA-genealogy research encounters one of these.
- Haplogroups apply to two major lineages in our family tree: Y-chromosome (YDNA) haplogroups and mitochondrial (mtDNA) haplogroups. YDNA is only found in genetic males and traces your father’s father’s father’s line, while everyone has mtDNA that traces their mother’s mother’s mother’s line.
Are you already lost? Go read this article first: “What is a Haplogroup?”
What is mtDNA haplogroup H?
Now we are going to look specifically at mitochondrial haplogroup H. NOTE: There is also a Y-chromosome haplogroup H, but it represents an entirely different part of the human family tree, so don’t get those mixed up! They really have nothing to do with each other.
Haplogroup H is the most common mtDNA haplogroup in Europe. Approximately 40% of all people in Europe have a maternal lineage belonging to haplogroup H. It is widespread, but it is also a relatively new branch of the human family tree (Fig 1).
The haplogroups on the left of this tree are the most ancient (L0, L1, L2 and so forth), and moving across to the right these haplogroups represent mutations that occurred in women more recently. Scientists have traced the root of this big beautiful tree of humanity to a woman that lived in Africa between 150,000 to 200,000 years ago. While it is likely that she was just one of thousands of women living at that time, she is the only one whose DNA has persisted in an unbroken chain of descendants to the current day. All living people on earth today can trace their maternal DNA lineage back to her.
People belonging to mtDNA haplogroup H can trace their lineage from Africa and earlier mutations forward in time to approximately 60,000 years ago, when a migration crossed the Red Sea into the Arabian Peninsula. As generations of women continued along their migration paths, their DNA occasionally changed (mutated). As this happened, like DNA bread crumbs along a trail, new branches of the haplogroup tree formed that are now traceable to certain geographies (Fig 2).
There is evidence that the specific mutation giving rise to Haplogroup H occurred in a woman tens of thousands of years later in the Eurasian Steppe near the Caspian Sea, and that it arrived in travelers to Europe prior to a major environmental event where glaciers covered much of the continent. Descendants of this intrepid group became a major source for the gene pool of Europe. That’s why we see haplogroup H in such a large proportion of European people (40%!).
Haplogroup H also expanded in all directions from the Middle East through Asia into Siberia, through Europe to North Africa, and into Arabia. But in these places, haplogroup H is found in lower frequencies than in Europe.
Subsequent mutations divide haplogroup H further into smaller subgroups (H1, H2, H3… and so on), the most frequent of which is H1, representing more than half of all of haplogroup H. H1 is most frequent in the Iberian Peninsula and then has other distant spikes in northern Europe and near the Caspian Sea, as shown in heat maps in this scientific journal article. H6a is found primarily in Iberia, and low frequencies elsewhere.
What does my mtDNA haplogroup tell me?
As we’ve touched on, mtDNA haplogroups represent deep ancestry that stems from mutations that happened up to tens of thousands of years ago. If you are trying to investigate recent ancestry, mtDNA haplogroups will not be able to definitively find your close cousins and distinguish them from thousands or millions of other people who share the same haplogroup.
Think instead of mtDNA haplogroup information as something that sometimes offers new clues to your research. Let’s look at how this can work.
I have northern European ancestry, so it was no surprise when my mtDNA report came back as haplogroup H. And more specifically, I belong to the subgroup H7a1. As a stand-alone, this is a nice-to-know piece of trivia about my maternal lineage. But let me show you how this has enhanced some of my investigations. I live in the United States, and my maternal grandmother (my very special Grandma Clark) was born in England and immigrated as a young woman to the US. What we know about her forebears gets fuzzy quickly.
Working my autosomal DNA match list in 23andMe, I can narrow down my shared matches to cousins who come from her specific lineage, using methods described in Your DNA Guide–the Book. This helps me see the people who are related to me through an ancestor of my Grandma Clark.
It’s possible that these matches are related to me through any of these deeper ancestors in her lineage (Fig 3).
Can you guess how using mtDNA haplogroup data can help me sort out this list even more? Any of these autosomal DNA matches who also shares mtDNA haplogroup H7a1 goes on my list for high alert of being related to me through our shared maternal lineage. And I’ve got a few of these!
An English gentleman named Tony is listed on my match list as my 3rd cousin, and his genealogy indicates that his maternal grandmother comes from Lincolnshire, the same area as Grandma Clark. And his mtDNA haplotype is H7a1! Bingo. This is some good evidence to suggest Tony and I are related on our maternal lines (Fig 4).
It doesn’t eliminate the possibility that Tony’s maternal line points to a different one of my female ancestors that is not on the strictly maternal line in Grandma Clark’s ancestry who also happens to be H7a1. It just gives me a high level of healthy suspicion that Tony is related to me on my strictly maternal line. And this can direct my further research efforts to dig into this more.
With just a few additional clicks using the Find DNA Relatives tool on 23andMe, I can find other people who are related to both me and Tony by shared autosomal DNA. And there’s a good list of people that comes up. And guess what, some of them also share mtDNA H7a1. There’s Otis from the Netherlands that has maternal ancestry in England, and Tricia in the US, and Angus in BC Canada, and an adoptee named Armond in the US (I might be able to help him out with some information about his maternal lineage, right?). I’m starting to get a nice cluster of people from my match list that I can pursue further to see if we can verify our suspected shared maternal ancestry, and see if they have any further information to expand what I know about Grandma Clark’s forebearers.
mtDNA Haplogroup H is so remarkably frequent in Europe. It’s a great place to get your hands dirty learning about how to use mtDNA haplogroup data in your own ancestry. Remember, all of the same concepts apply whether you’re from haplogroup L, D, P, Q, H or anything else:
- Your mtDNA haplogroup represents deep ancestry on your strictly maternal lineage. It can possibly link you to a characteristic geography or ethnicity.
- And while haplogroup information by itself typically doesn’t help you find close family, further subdivisions of your haplogroup may offer some information to enhance what you know about cousins from autosomal DNA.
What other applications do you see for your mtDNA haplogroup data in your research?
As I mentioned, you can learn the strategies to narrow down your shared matches to cousins from a specific line in Your DNA Guide–the Book. Plus the book offers additional information about mtDNA , haplogroups, and other strategies so that you can DO the DNA!