Preparing for National DNA Day – Part 2 Y-DNA and mtDNA

DNA

April 25 is National DNA Day so in preparation, we are going over the three types of DNA kits that you will be able to purchase. Last week we talked about Autosomal DNA and you can read the article HERE. This week lets talk about Y-DNA and mtDNA.

Y-DNA

A Y-DNA test will provide you with your direct male line information as the Y chromosome is passed almost unchanged from father to son. YDNA also shows where you’re direct paternal ancestors came from. As you may have already guessed this test can only be completed by males.

There is only one company that I’m aware of that can provide Y-DNA testing.  Family Tree DNA (FTDNA) which was started in 2000.

After you decided to do a Y-DNA test with Family Tree DNA, the next step is to decide how many markers you should test at as you can test at 37, 67 or 111 markers. As with most things, more is better. Ok, maybe not desserts.  But if costs are a factor then at a minimum you’ll test 37 markers.  This will tell you that yes you are related to your match but if you want to learn more, then you will have to test more markers. However, this will only help if your matches have tested to the same number of markers as you.  So if you tested to 111 markers and they have only done to 37 markers then that is as much as you’ll know. If you wanted to learn more you would have to convince them to purchase an upgrade to the kit.

So why isn’t 37 markers enough? Well, it’s because the more markers you test the more accurate the relationship becomes. What you’re looking for is a low genetic distance and the greatest number of markers tested. So if you have a genetic distance of 0 at 37 markers when you test at 67 or 111 markers you’re hoping that the distance remains at 0 because that means you have a more recent ancestor with your match.

So in the case of my father whom I’ve tested at 111 markers; if you look at his 37 marker matches he didn’t have anyone that matched until very recently. At 67 markers he has two matches but they are both at a genetic distance of 7. This means that their most common ancestor is probably within 16 generations or more.. probably more like 24 generations. Both of these men have tested to 67 markers if they were to test at 111 markers they probably wouldn’t show any longer.

In the case of my brother-in-law; Don who is adopted; when we tested him at 37 markers he had one match and that was at a genetic distance of 3. A distance of 3 meant there was an 83.49% chance that their common ancestor was 4 generations away. This match helped to discover who his father was and the actual genetic distance from his match was 5 generations. I do have to say that it was with the use of the Y-DNA and his autosomal matches that I was able to determine who his father was. But it took many hours of research and also getting a few more people to test before we got there.

Speaking of upgrades, once Family Tree DNA has your sample you can upgrade the test anytime and you can also purchase other tests (such as atDNA or mtDNA) without sending another sample until such time as your sample runs out. Family Tree DNA also offers a Big Y test for the most advanced test of your Y-DNA.

The YDNA test will also provide an ancestral migration route of the genetic population of your paternal line. This is your deep ancestral roots.  You will also get your paternal haplogroup information.

mtDNA

mtDNA provides you with your direct ancestral female line. This test can be completed by both males and females.  This test is available at Family Tree DNA.For mtDNA, the levels are HVR1, HVR1+HVR2 and Coding Region, which equate to the three levels of tests that you can take. It’s my understanding that you can take the three levels of testing but if you are going to do mtDNA testing you want to opt for the highest level.

I’ll be honest with you. I haven’t done a  lot of mtDNA testing on my family members. I’ve tested my father many years ago and I haven’t really done a lot with it as my dad again doesn’t have close matches. As I understand it you are looking for nothing less than a genetic distance of zero.

As I understand it mtDNA is not as helpful for genealogy purposes. But what it can do is if you have a situation where you believe two females are related via their mother’s line then by testing you would be able to confirm that.

A mtDNA will also provide an ancestral migration route of the genetic population of your maternal line. This is your deep ancestral roots.  You will also receive your maternal haplogroup information.

Stay tuned and keep your eye out for posts in the upcoming weeks as the DNA companies offer special pricing for National DNA Day. You’ll be able to find them on our Genealogy & DNA Treasure page.

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