Friday, May 25, 2012

23andme- Ancestry Painting

Remember when I said that genealogy was never boring?  Well, I lied--sort of.  One feature offered by genome testing at is that they are able to calculate the geographic origin of each of your chromosomes going back about 500 years.  Everyone inherits half of the DNA on their chromosomes from each parent, and everyone (unless you have an extra chromosome, such as Down's Syndrome patients) has 23 pairs chromosomes--hence the name of "23 and me."

To calculate your genetic ancestry, 23andme uses three basic populations: European, African, and Asian; and compares your DNA to populations on those continents.  Note: Native American and Pacific Islander ancestry is classified as "Asian," as those populations were thought to have drifted from Asia to the east.  On your Ancestry Graph, there are two segments represented for each chromosome, one segment that you inherited from each parent.  If that segment was European in origin, it will be colored blue, if African, green, and if Asian, orange. 

Why provide this information?  It is known that certain genes control specific functions in your body. If you carry Europeans DNA on certain chromosomes, you may be more resistant or susceptible to some diseases. Likewise, Sickle-Cell anemia will be African in origin. Secondly, the most obvious reason is for genealogical purposes. Lots of Americans claim to have descended from  a "Cherokee princess."   Ancestry painting will show if you have inherited "Asian" DNA.  Likewise,  African-Americans can see how much European DNA they have inherited, and most Hispanics will have a high European percentage combined with the Native American "Asian."

An African-American's Ancestry Painting:


A child of an Asian mother and Italian father:



100 % European. No Cherokee princess.  Boring........

1 comment:

  1. One caveat: One of your parents may have European, African, or Asian DNA that did not pass down to you---remember you get 50% of your DNA from each parent. So if my mother or father had a small amount of Native American or African DNA, it is possible that it did not pass down to me. I am still related to that distant ancestor, I just did not inherit any of their DNA.