What are Maternal and Paternal Haplogroups.



I have always had an interest in genealogy and now with modern tests you can test your genome to track your ancestry, but what do these haplogroups tell you about yourself?

In: Biology

If you are male, you received a Y chromosome from your father. And that was a copy of his chromosome, which was a copy of his father’s, and his father’s, and so on. Unless there was a mutation error, so that a man with a section of genetic code saying “AGAGTCTC” ended up giving one his sons “AGA**T**TCTC” instead.

By looking at the Y-chromosomes men around the world have, how different from each other they are, and where they are the same, we can build up a possible branching family tree of groups of men who must have shared a great-great-great…-grandfather. We call this a haplogroup. If you’re in the same haplogroup with a bunch of men currently living in Russia, you probably have Russian ancestry!

The same principle can also apply to everyone, male or female, because the DNA in the mitochrondia of our cells comes only from our mother. So you build up a tree of how groups of people with the same or similar mDNA shared great-great-great…-grandmothers with others in their haplogroup.

When DNA is passed down to children, you get 50% of your DNA from each parent. So DNA is a scrambled combination of genetic material from your parents. However, there are 2 types of DNA that are handed down unchanged (except for random mutations) from each parent. These types are: mitochondrial DNA (mtDNA) and the y-chromosome. mtDNA is located outside of the cell nucleus and is separate from the 46 chromosomes that almost everybody has inside their cell nucleus. All mtDNA comes from the mother. So whatever your mtDNA is, is your maternal haplogroup. It’s useful for genealogical purposes because it means that it has been handed down from mother to child forever. And scientists have traced approximately where your mtDNA originated geographically, so by knowing your mtDNA, you can know where your mother’s mother’s mother’s etc. came from. Everybody has mtDNA so can do this.

The other type of DNA that is handed down unchanged is from the Y-chromosome. The father gives the son his y-chromosome unchanged, so like with mtDNA, we can figure out where that y-chromosome originally arose, and that’s your paternal haplogroup. So if you have a y-chromosome that originated in east Africa, then we can say that at some point you had an east African ancestor who was your father’s father’s father’s etc. father. Only people with a y-chromosome can use their paternal haplogroup in this way since if you’re XX, then you don’t have a y-chromosome.