Monday, December 19, 2011

In The Genes

Please Click Image To Enlarge

I was asked about genealogy and DNA today.  I thought it would be nice if I posted a partial picture of my DNA chart I was given from Ancestry.com.  That top line is me.  This is a Paternal Lineage Test, so my brother took the test for me.  Now, if you put my brother and me in a room together, there'd be no doubt we both fell off the same turnip truck!  LOL!!!!  We definitely share the same DNA.

A few things you should know:  1.  This is a 46 marker test.  Forty-six different values were tested, which are represented on the right (DYS19a, DYS19b, etc); 2.  Basically, the more markers that match another person (represented here by the number of lines), the closer related you are; and 3.  MRCA, or Most Recent Common Ancestor, refers to how many generations apart a common ancestor likely lived.  The MRCA number for me and the person on Line 1 is 13 generations.  Our common ancestor likely lived around 13 generations ago.  That would be my father's father's father's father's....plus eight more father's father side.  You get the idea.  Or if you don't, if a new generation is born every 25 years or so, our common ancestor lived about 325 years ago.

Now I'd like to bring attention to the word likely.  Because DNA mutates, there is actually a probability rate for determining MRCA.  So basically, the kind folks at Ancestry.com are telling me that it's more likely than not my most recent common ancestor with the person on Line 1 was 13 generations ago.  In reality, there's really a 50.2% chance that our common ancestor was 13 generations ago, about a 75% chance it was 18 generations ago, and a 97% chance our common ancestor lived 30 generations ago*.

If you are curious about your haplogroup, genealogical DNA can be very fun and informative.  At this time though, do not expect it to break through any of your brick walls.  By the way, I belong to Haplogroup R1b.

*To determine MRCA probability, there are several good MRCA Calculators out there, like this one.  To understand more about genetic mutations, I suggest reading up on MRCA, alleles, and the infinite alleles model.  Pretty techie DNA stuff.

No comments: