Mitochondrial DNA


What is Mitochondrial DNA?

We all get our genes from our parents and pass them onto to our children.Over thousands of years the genes mutate and leave distinct genetic markers.Humans beings evolved in Africa and migrated out of Africa to populate the Earth.This took many generations to accomplish and over this period the genes passed on from one generation to the next gradually mutated leaving genetic markers among populations that settled along the way.Therefore it is possible to analysis the genes of populations and use the information to track their long term history back to Africa.


There is one type of DNA which is passed from father to son and another type (mitochondrial DNA) that is passed from mother to child.


When tracked all the way back mitochondrial DNA (mtDNA) leads back to one woman who, remarkably, all the people alive today are descended from.This doesnít mean that she was the only woman alive at this time, it just means that all the other women around at the time had their mtDNA gradually filtered out by only having boys or not having any children.To give you an example.When the descendents of the Bounty were finally discovered after 25 years on Pitcairn Island most of them had the surname Christian.That doesnít mean that Fletcher Christian was the only man who settled on the island.It just means that some people hadnít had children and some had only girls so the variation in surnames gradually diminished.Itís the same with mtDNA.


In our case, Mary, Teresa and Kathleen Dagleish all got their mtDNA from their mum, Helena Chapman, and passed it onto all their children.This is the mt DNA which grandma got from Mary Stephenson who got it from Mary Elizabeth Dean who got it from Elizabeth born in Salford, who got it from her mum.Sarah, Anne-Marie, Rachel, Ruth and myself have all passed it onto our children, and so will Helen if she has any.Amy, Helena, Abigail and Phoebe will pass it onto their children but Michael, Leo, Ben, Joe and Sam will not.


National Geographic are running a project called the Genographic Project which examines the DNA of those who take part, like me.To look at the results log onto


and enter the genographic ID number†† FWGPAUBJ6R


It gives a map showing the route our female ancestral line has taken out of Africa and talks about the history of the haplogroup that we belong to, which is K.There are also explanations of mtDNA which are likely to be clearer than mine above!


Back to Helena Chapmanís family tree