How to Make Use of Italian Y-DNA - new results and new to Y-DNA

+5 votes
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I have received the results for my brother's Y-67 test and don't know where to start - will be uploading to gedmatch shortly, and entering the test info here shortly as well. Our earliest known Italian ancestor was Giulio Ferracci [[Ferracci-9]] who died around/before 1884 in Petina, Salerno, Campania. My brother < Donald Ferracci [[Ferracci-5]] < Nicholas (Nicola) Ferracci < Giulio Ferracci < Nicola Ferracci b. 1824 < Giulio.

Thanks in advance for any help!
in Genealogy Help by Theresa Myers G2G6 Mach 1 (13.5k points)
Gedmatch is for autosomal DNA. You cannot upload Y-DNA there.
I have his autosomal results as well, of course.

1 Answer

+1 vote
Y-DNA will help you see which men carrying the Ferracci surname your brother is related to. Or, if there's a break in the paternal line where somebody isn't who he's supposed to be, or somebody changed their surname, that will be reflected as well.

It can't really tell you, with any level of precision, HOW CLOSELY you're related to anybody, though. Mutations are like rolling dice - you can hit a "six" on the first roll, or it might take 10.

Normally, your relatives, even out to 8th cousins or further, will only differ on one or two of the numbers. There's a little extra trickiness for the STRs that are doubles or the quadruple one. The "genetic distance" they count is basically a count of mutations.
by Frank Stanley G2G6 Mach 6 (67.0k points)
There is not a single match named Ferracci. I know it's not a common name, but it's surprising to find none. Are there any other ways to use the results?
In DNA testing, one cannot necessarily expect that someone of your surname will show up. The testing done is a very small percentage of the population, and is heaviest in the US. Besides, testing of people with any given surname will be uneven and tends to cluster. A number of years ago, my surname had hardly any activity, but once it got going more people were recruited. There is no Ferracci project at FTDNA. At Forebears.io, there is an estimate of 2,321 instances of the surname worldwide, only 120 of them in the US where most testing is done. To me, it is not at all surprising that there are no other Ferraccis. In your case, the process is to identify what you know about the earliest known Ferracci ancestor and try to identify and recruit the most distant Ferracci male you can find to determine if even your own line is intact. I might add, that I have seen people with supposedly common names who don't closely match anyone in the FTDNA population. That doesn't mean they don't have a match, but that participation is far from random.

Agreed.

2321 in the whole world? Yikes!

That's certainly a reason for optimism, though. Y-DNA results don't mean anything by themselves - you have to have other people to match against. Now that the brother has tested, the value of the test for other Ferraccis is much greater, so maybe you'll see some others show up in the months and years to come.

You also have to consider the small possibility that somebody in the paternal line (either your brother's, or the other guy's) isn't who they were thought to be. Are there matches that are NOT named "Ferracci"? If so, what's the genetic distance? If this sort of thing happens to be going n, then it will be reflected in the autosomal DNA too, but that test ALSO has the problem that testing is much more popular in the US. It turns out that most Italians already have a good idea that they're Italian... wink 

There are 3 pages of matches with all kinds of different surnames, genetic distance ranges from 4 to 7. I'm not sure how to organize it, or how to make sense of the SNPs and STR - all Greek to me.
I'd just look at the STR umbers as a sort of "code" or fingerprint. If one of them is different that the other guy's that a mutation adding 1 to the "genetic distance".

By my calculations, the chance of having 4 or more mutations between various degrees of cousins are:

1C: 1.2%

2C: 4.5%

3C: 10.3%

4C: 18.3%

5C: 27.6%

6C: 37.6%

So a less-than-50-50 chance, even for 6th cousins.

I guess maybe there's a tiny chance that somebody's papa wasn't who they were supposed to be, and is a 4th cousin, for example, who has shown up on your list, but since none of the surnames match, and none of the genetic distances are very close, probably the thing to do is to just check back every few months and see if a new test has been done that has a more interesting result. Because I think there's such a thing as the "codes" for different surnames just happening to be somewhat similar.

I don't suppose that sounds very exciting, but if and when a closer match with the same surname shows up, THAT will be interesting. Sounds like you're just "blazing the trail." Somebody has to be first!
Certainly, there are plenty of matches showing up at GD 4-7 @Y67. A few of my Beasley tests (particularly the ones not matching other Beasleys) are constantly getting hits like that. As a practical matter, though, matches are rather meaningless in the absence of documentary evidence establishing some kind of proximity in a reasonable time frame. I put the greatest value on Y67. Y111 is nice but can only be compared with Y67 or less unless you get a lot of tests going at Y111. Most of the results I can work with are GD 0-3 @Y67. I have NEVER found 2 Beasleys with a Genetic distance of 5 or more... rarely at 4. In my project, these matches are ALWAYS mismatched surnames and as such offering no clues as to where the link might be. There has been one occasion where I have been able to discover the actual connection between two men with different surnames, Beasley and PItts (GD2@Y67). In that case, the common ancestor was born in the mid-1600's and we had clear evidence that the two families were closely associated. In several other cases, I have seen two surnames that seem like they might connect (at GD3 or better) but it would take a lot of research time to maybe figure it out. My project is too big to focus my energies on that. Anything further than GD3 @Y67 is, to me, remote.

OTOH, there is one other factor to consider when looking at the Genetic Distance that may shrink a GD4, for example. That's to consider the Modal profile. When you have a greater number of matching YDNA tests, you will begin to see that, for each allele, there is one value that is most common. The modal profile is the collection of all the most common values. Therefore, it is possible that two men of GD4, might each be GD2 from the modal. But, you can't know that until you collect a number of matching tests. In the case of the Beasley project, we have some men who are GD3-4, but they are all GD2 from the modal. In the case of the Beasley/Pitts match, each man is GD2 from one another, but GD1 from the modal. That means that each of the four men tested had only 1 mutation since the 1600's.

The bottom line of what I'm saying is that your time would be better spent trying to recruit other Ferraccis for the Y test. A whole lot of pages of GD 4-7 matches are hardly worth the effort IMHO.
When you say "a number of matching tests" (to construct a modal profile), you mean tests from a number of known relatives?  I don't know any other Ferracci's, my brother is the last of the known line. My second great GF may have had a brother, not sure. The only other Ferracci I have ever found is Eraldo Ferracci, who owns Fast By Ferracci - a motorcycle builder and racer. I've reached out to him a number of times wondering, but never received more than a nod back. He's in his 80's. Slim pickin's!
Matching may not be the best term but what I mean is two tests with a GD7 or better @67 (GD4@37, GD10@111). Technically that's so but practically, in my experience, GD3@67 or better. Even then, it doesn't mean much in the absence of documented evidence. What's practical for me isn't going to be practical for you.

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