You are more related to some of your grandparents than others


painting by Jim Abeita

There is a great article on Slate magazine by my favorite genetics blogger, Razib Khan.  I read his posts daily on Gene Expression and it is nice to see him on something that will get his erudite writings on a complicated subject to a larger readership.  The article is titled, Which Grandparent are you most related to?, and Razib proceeds to explain how you are not related to each of your grandparents equally and how you can go about testing that with a test from the company 23andMe.

The short of why you are not related to your grandparents equally goes back to Mendelian genetics, which states that you get half of your genome from your father and half of your genome from your mother.  But that does not mean that you are getting exactly a quarter from each grandparent.  The process is random so you most likely get a different percentage from different grandparents.  You could also get nothing from some of your grandparents being that there is a 1 in 4 million chance  you could get all of your maternal or paternal chromosomes from just one grandparent.

The advantages of knowing this is not trivial but can lead to a better understanding of deleterious genetic conditions that you may inherit from your parents or grandparents.  Check out the article to read more.

Marie Antoinette’s Mitochondrial DNA thwarts Pretenders to the French Throne


Marie Antoinette as seen in better, more cake-filled days

After the French Revolution and the mysterious death at age ten of Marie Antoinette’s only son Louis Charles, there were many people who came forth claiming to be the little prince.  The most famous was a German clock maker named Karl Wilhelm Naundorff.  Naundorff even had the backing of Louis Charles’ nanny and Louis XVII was written on his gravestone!

Now enter good ole science.  Naundorff’s body was exhumed and his mitochondrial DNA was tested and compared to mDNA from locks of the executed Queen’s hair and her descendants.  And voila, no match.  Poor Louis Charles had died in prison and didn’t escape to make clocks.

Source I09

Europeans are now more related


Charlemagne is your ancestor

Bron of the Boring Stories

Bron of the Boring Stories is also your ancestor

One of the great tropes of American genealogy is to trying to find out if you are descended from European royalty or a Native American (Cherokee in North Carolina, Pocahontas in Virginia).  Now, if you are of European ancestry, you can go ahead and assume that you are a Duke, Earl or an heir of Charlemagne.  It turns out that Europeans are much more closely related than previously thought,  at least according to a new paper by geneticists Peter Ralph and Graham Coop.  They studied DNA from 2257 people from across Europe and found that between two people there will be a segment of DNA that is identical. The longer that segment is the closer the two people are related. From their study they found that “… everyone who lived a thousand years ago who has any descendants today is an ancestor of every European. Charlemagne for everyone!”  But not only are you a descendant of Charlemagne but you are also a descendant of Cedric the Poor Planner and Gwendolyn the Disappointing, so it’s not all good.  No news on Pocahontas though.

Source The Loom