November 22, 2012 at 4:59 am #72
I’ll start with a basic overview and with the assumption that you are new to DNA genealogy and hope that I’m not trying to tell you how to suck eggs . I’ll be the first to admit that I am also a novice but very excited about this line of enquiry.
I had my DNA tested through https://my.familytreedna.com and have pursued a number of tests. The best way I have heard it described is like this. If you hold your arms out in a V shape in front of you, one arm contains the YDNA which only males have – that is passed down from father to son and for all of us who are of western European origin we can all trace that back to an African Adam around 50,000 to 60,000 years ago. He wasn’t the only male alive at the time, he is just the only one whose sons have had sons all the way down to the present day. If we see him at the trunk of the tree and then trace it forward in time, each branch of the tree marks a mutation in the YDNA that is passed onto all the subsequent generations from that person. Thus we can build a family history that shows how closely we are related to others by knowing which markers we share – the more we share the closer in time is our shared ancestor. In your case you won’t have YDNA but your brother, if you have one, would have inherited that from your father.
The second arm contains the mitochondrial DNA which males and females inherit from their mother and from her mother etc. This can also be tested in the same way and match people descended from the same woman. In my case it has confirmed for me that my 3x Great Grandmother was an Australian Aboriginal which until recently had simply been in the realm of family legend.
The space between the arms contains the other 22 chromosomes that we all carry and which are inherited in equal parts from out mother and father who in turn got it from their mother and father. Your siblings will not test exactly the same as you because it is a random inheritance unless they are identical twins. But this test looks at strings of DNA that match. The longer the string and the more parts of the chromosome that match the more closely related you are to other people. At http://www.myFTDNA.com this is called the family finder test and for me that has revealed matches with in excess of 300 people. The problem is that unless you can match your tree through traditional genealogy or through common surnames, it is difficult to narrow down which particular line of ancestry you share given the number of people we inherit our DNA from doubles each time we move back a generation. So I am in the process of convincing other relatives on both my Mum and Dads side of the family to get tested so that we can start to narrow down which lines to pursue.
With each passing year and as more people test and share their results the rich tapestry that connects all of us is becoming more and more clear and that gap between pre-history and the traditional paper trail of genealogy is narrowing.
So if anyone wants to know where to get tested then let me know and I’ll point you in the right direction
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