LegacyTree Genealogists is a genealogy research firm founded in 2004 and based in Salt Lake City but with professional researchers in many different places around the world. They do quite a bit of DNA work, which is how they got on my radar a few years ago.
Today, LegacyTree Genealogists released a new Inheritance Chart Tool for mapping a grandchild’s DNA to his or her four grandparents. The tool produces a chart showing exactly what segments of DNA came from which grandparent, along with a spreadsheet of those segments. There’s a blog post here: “Discover What You’re Made of with Grandparent Inheritance Charts.”
One of the things I like best about this tool is the ease with which you can create a spreadsheet to upload and use the tool. At a minimum, you need three things:
- A tested grandchild;
- A tested paternal grandparent (either grandfather or grandmother); and
- A tested maternal grandparent (either grandfather or grandmother).
That’s right, you only need one grandparent on each side tested. This is because any DNA you didn’t get from a paternal grandfather must have come from a paternal grandmother, for example. You can, of course, use 2, 3, or 4 grandparents, depending on how many you’ve tested.
Here is a screenshot of the output of a grandchild’s DNA, using only only grandparent on each side:
On average, a grandchild receives about 25% of their DNA from each grandparent, but it can vary quite a bit. Here, you can see that on the maternal side, Luke inherited about 18% from his maternal grandfather, and a whopping 32% from this maternal grandmother. Instead of being 1/4 of a grandparent, he is 1/3rd!
I can’t really do this for myself, unfortunately, as I wasn’t able to test any of my grandparents. Although I’ve recreated almost 100% of my paternal grandmother’s genome, I don’t have a comparable amount on the maternal side. However, I did try it with just the paternal grandmother’s recreated genome, and it worked very well to assign my paternal DNA.
(NOTE: this is not a sponsored post, my blog doesn’t do any sponsored posts. I just like the ease of using this new tool).