Haplogroups relate to our deep ancestry.  Deep ancestry is not traditional genealogy:  it is not for tracing family or confirming family linkages.  Deep ancestry is a look at our ancient ancestral roots from tens of thousands of years ago and shows how all people living today are connected to an ancient ancestor who lived in Africa over 100,000 years ago. 

Haplogroup studies have been around for many years in the scientific community.  Many will remember seeing the traditional biology 101 textbook diagram (phylogenetic tree) which shows how all living organisms are connected:

A phylogenetic tree shows the evolutionary relationship of biological species believed to have common ancestor.  In a phylogenetic tree, each node with descendants represents the most recent common ancestor of the descendents. 

Humans represent one branch of the phylogenetic tree of all living organisms.  The human branch of the phylogenetic tree was built based on DNA, in particular, SNP markers found in human DNA. 

Our Y-DNA, which is passed down from father to son shows that the Y-DNA of every male living today can be traced back to a common male ancestor who lived in Africa over 100,000 years ago.  He is often termed the “Y-Chromosomal Adam”.

Likewise, our mtDNA, which is passed down from a mother to her children shows that all people living today shared a common female ancestor who lived in Africa over 100,000 years ago.  She is often termed the “Mitochondrial Eve”.

The type of genetic markers used to build the human phylogenetic tree are called SNP (single nucleotide polymorphism) markers.  SNP markers are found in both the mtDNA and the Y-DNA.

The main branches of the human phylogenetic tree are called “Y-DNA haplogroups”.  The Y-DNA tree has approximately 18 main branches “Y-DNA haplogroups”, classified by the letters A to R.  Each Y-DNA haplogroup has many further sub-branches (subclades), classified by numbers and letters i.e. R1A, R1b1, R1b2, etc. 

The mtDNA tree has approximately 26 main branches “mtDNA haplogroups” classified by the letters ”A to Z”.  Each mtDNA haplogroup has many further sub-branches (subclades), classified by numbers and letter, i.e. L1A1, L1A2, L1B, etc.  All people living today have descended from of the main branches of the human mtDNA phylogenetic tree.

By testing the SNP markers in your Y-DNA and mtDNA, you will be able to tell which branch of the haplogroup tree you belong to.

Of course, each main branch has further sub-branches or “subclades”.  Once you know which haplogroup you belong to, you can then focus on your sub-clade through “subclade testing”.

Facts and Common Misconceptions:

• No, haplogroups are not the same as haplotypes.
• Yes, all people living today fall into one of 18 main Y-DNA haplogroups on their paternal line, and one of 26 main mtDNA haplogroups on their maternal line.
• No, haplogroups will not show if you are related to someone (unless you count distant relationships from thousands of years ago).
• Yes, once you know your haplogroup, you will be able to view how your haplogroup migrated out of Africa and retrace their migration routes.
• No, haplogroups will not add people to your family tree or allow you to trace your surname (that’s the job of STR haplotypes).
• No, haplogroups will not tell you precise migration routes, it will show a broad migration route and population distribution.
• No, if you and someone else belong to the same haplogroup, it does not mean that you are closely related.
• Yes, once you know your haplogroup, you can often fine tune your branch of the haplogroup tree through subclade testing.
• No, you cannot confirm your haplogroup through STR testing or HVR1 testing.  A Y-DNA STR test and HVR1 test will often allow you to predict your haplogroup, but only a SNP backbone test will confirm the prediction.
• No, SNP backbone testing will not give you information about sub-clades.  It will confirm your haplogroup.  Once your haplogroup has been confirmed, a subclade panel test for your particular haplogroup will trace your subclade. 
• Yes, STR testing can give predictions for haplogroups and even some sub-clades, but the backbone test can only confirm the haplogroup, not the sub-clade.
• Yes, subclades are determined through SNP subclade testing (once your haplogroup has been confirmed)
• No, your haplogroup will not tell you if you are Welsh or Irish.  It will not tell you your ethnicity.  Although there are associations between ethnic groups and haplogroups, you must remember that haplogroups represent deep ancestry, tracing events from tens of thousands of years ago.  It does not tell you what your ancestors have been up to over the last few hundred years (that’s the job of Y-DNA STR markers, and applications such as Surname Projects, which will be the topic of another blog). 
• Yes, all people living in the world today are connected in the human phylogenetic tree.  Just like how all people belong to a certain blood group i.e. A, B, AB, O which can be determined through testing, all people also belong to a certain haplogroup which is unique to their ancestry, and their haplogroup type can be determined through genetic genealogy testing.