Ancestry.com has improved the ability of AncestryDNA to find good matches for Jewish, Hispanic and other ancestries that maybe weren’t so precise before. Here’s the lowdown, quoted liberally from Ancestry.com’s press release:
The problem: Predicting genetic relatives among customers of Jewish and Hispanic descent and some other groups. “In DNA matching, we are looking for pieces of DNA that appear identical between individuals,” says the release. “For genealogy research we’re interested in DNA that’s identical because we’re both descended from a recent common ancestor. We call this identical by descent (IBD). This is what helps us to make new discoveries in finding new relatives, new ancestors, and collaborating on our research.”
“However, we also find pieces of DNA that are identical for another reason. At one extreme we find pieces of DNA that are identical because it is essential for human survival. At the other, we find pieces of DNA that are identical because two people are of the same ethnicity. We call these segments identical by state (IBS) because the piece of DNA is identical for a reason other than a recent common ancestor. This, we have found, often happens in individuals of Jewish descent.”
“The challenge in DNA matching is to tease apart which segments are IBD, and which ones are IBS….Most Jewish customers find that we predict them to be related to nearly every other Jewish customer in the database….Detecting which cousin matches were real and which ones were bogus has always been a challenge for these populations.”
First step toward a solution: “By studying patterns of matches across our more than half a million AncestryDNA customers, we found that in certain places of the genome, thousands of people were being estimated to share DNA with one another–likely a hallmark of a common ethnicity. Our scientific advancements… have allowed us to effectively “pan for gold” in our matches–by throwing out matches that appear to only be IBS, and keeping those that are IBD.”
“While the problem was more pronounced in customers of Jewish and some Hispanic descents, we observed this problem across all ethnic groups. So, all customers will see increased accuracy of their DNA matches, and significantly fewer ‘false’ matches.”
AncestryDNA results with better matches found by this method “will be available in the coming months,” says the release. They plan to email existing customers when results are ready.
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You may recall from our recent DNA discussion on the Genealogy Gems podcast (Episode 168) that Ancestry.com recently discontinued their mtDNA and YDNA tests (the two that trace our direct maternal and direct paternal lines) to focus on autosomal DNA (which delivers information about both your mother’s and your father’s side of your ancestral tree).
Well, recently I attended an all-day meeting hosted by Ancestry.com: a summit to talk about current trends and accomplishments at Ancestry DNA, and ideas about the future of DNA testing at Ancestry.com.
The meeting included a diverse group of Ancestry representatives, from CEO Tim Sullivan to members of the marketing, scientific, communications, and even computer science departments, as well as some of the top voices in genetic genealogy. It was an open and lively discussion, and I walked away with a few gems I want to share with you today.
More Powerful DNA Hints Coming
In AncestryDNA, the ‘shaky leaf” hints are meant to help you find a common ancestor between you and your DNA matches. The computer code behind the old hints was not very efficient. Lazy, in fact. It started at the bottom of your tree—and the bottom of your match’s tree—and slapped on a shaky leaf at the first sign of a shared common ancestor.
While this method worked for a large number of cases, it was leaving a lot of stones unturned. But the IT guys at Ancestry have beefed up the computer power, allowing them to cover a much greater distance through our trees and the trees of our matches before making a judgment about the best place to assign that shaky leaf.
The result? Better hints about how you and your match COULD be related. Remember, the leaf is still just a SUGGESTION on how you and your match might be related. It is not a crystal ball.
Did You Know?
- Ancestry DOES store your DNA samples in a secure location.
- Ancestry spent months designing their own DNA collection kit.
- Ancestry was able to attract some of the brightest scientists in the field of population genetics because of YOU. You with your documented pedigree charts and your willingness to help move this science of discovering our ancestors forward.
There is no question that the genetic genealogy industry is rapidly advancing, and our discussion with Ancestry certainly didn’t disappoint. While I will be sharing with you in future posts about some of the exciting changes, I do want you to be ready for one that buy anxiety medication online uk will be coming online fairly soon.
It has to do with your matches. If you have been tested by AncestryDNA, you may have been initially excited, then nearly immediately overwhelmed, by the number of individuals listed in your match page, all claiming to have some kind of connection to you and your family tree.
All three major genetic genealogy testing companies (AncestryDNA, Family Tree DNA, and 23andMe) are using basically the same laboratory methods to glean information from your DNA. What differs is how they use that data to draw conclusions about your ethnic heritage and about your relationships to other individuals. As it turns out, AncestryDNA has been reporting far more individuals as your relatives than it should have.
You can think of it like this: You have sent out tickets, in the form of your genetic code, to an exclusive party where you (of course!) are the star. However, you have lost the guest list and you are counting on the testing company to check the ticket of each guest before they enter your party to be sure they were really invited.
AncestryDNA was relatively new in the role of party bouncer, and in the interest of not turning away any VIP guests, they initially allowed guests into your party who had (gasp!) forged tickets!! But as AncestryDNA admits more guests, the experience it’s gained in party monitoring is starting to show.
You see, each of the forged tickets has some unique qualities that have started to send up red flags to the team of scientists at AncestryDNA. They are now in the process of carefully documenting what each forged ticket looks like and tossing those unwanted guests out on their ear.
The short of it: in the near future your match list at Ancestry will be much shorter. Which is good news to you, as it means only those invited genetic cousins will be around eating hors d’ oeuvres and ready to talk about your shared common ancestry.
Each testing company has its strengths and weaknesses. It was good to have a bit of insight into this one company and come to a greater understanding about why it is they do what they do. It is a great time to be in this young genetic genealogy industry, with so much room to grow and change. I will let you know when I find the next genetic gem.
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AncestryDNA announced last week that it has been able to identify six unique historic populations in West Africa. It’s a breakthrough they call a “finer-resolution genetic ethnicity estimate for individuals with West African ancestry.” They have even used this technology to start connecting the dots between those groups and millions of African-Americans whose ancestral paper trail was annihilated during the era of slavery.
For this latter development, the AncestryDNA team uses the “cluster genealogy” approach: the concept that people from the same location often migrated to the same areas. Of course, slavery forced apart families and other natural migration groups, both in Africa before the crossing and in the U.S. or other destinations. And the few records that remain of many of these folks and their enslaved descendants don’t include full names, place of origin or other data we rely on to make family connections. (Learn more about how to research African-American roots in Genealogy Gems Podcast Episode 159 with Dr. Deborah Abbott.)
It’s encouraging to read that AncestryDNA has had some success hooking up regional groups of African-Americans with specific areas of Africa. “Though this project is still in its infancy, the science team has made some progress,” AncestryDNA reports. “First, we looked at the birth locations of individuals in the trees of all African Americans. Then, we looked for locations where, relative to all African Americans, there appeared to be an over-representation of birth locations in trees of individuals with a particular West African ancestry. For individuals with Senegalese genetic ethnicity, we found what seems to be an over-representation of birth locations in South Carolina and Georgia in the 1700’s and 1800’s.”