Ancestry DNA results

[_Jersey Girl]

What does that mean?

ETA: If you are making jokes, I'm looking for serious replies. Not comedy hour.

In Mexican culture "Sancho" is the "other man"...it is used in that culture like we use the term "milk man."

My siblings ( 3 that tested) in our DNA testing came back within 100 cm...as do most of my nephews and nieces, and first cousins....but never more than 200 cm. (Ancestry)

So again, it may appear that Sancho might have been in town. I am both joking and being very serious.

No. You aren't being serious. If you were serious, you would READ the posts that I've written here regarding second cousin results on DNA tests. What you stated above does NOT answer the question.

Lighten up.

Read up. Stop wasting my time.

[_Lemmie]

Are the aunt, uncle, and parent siblings? Or did the parent marry a sibling of the aunt-uncle sibs?

[_Jersey Girl]

Are the aunt, uncle, and parent siblings? Or did the parent marry a sibling of the aunt-uncle sibs?

Hi Lem! Yes, the aunt, uncle and parent of the person are all siblings. They presumably share a mother in common. I'm not sure about their father.

The parent of the person did not marry a sibling.

If you look at the values I extracted from charts that state cM ranges, even a half sibling would not show as a second cousin. I don't know how to explain these results and it's important to all concerned that they get answers.

Looking in on this from the outside, can you tell what I am missing?

I'll be calling Ancestry customer support this afternoon. I'm hoping that I don't need an account number to do so. I do have two people sending written inquiry to Ancestry as a back up plan.

My knowledge of DNA tests is limited to knowing what test to use for what purpose. I think...that if the uncle or father were to do a Y chromosome DNA test, and the aunt following that, it would show whether or not the break is due to having different fathers and then case closed.

That still doesn't explain why Ancestry shows the aunt as a second cousin.

[_Jersey Girl]

According to the charts that I linked to and referenced, the aunt's 609 cM's put her closer in relation to the person. It doesn't push her down the chain to second cousin.

[_Jersey Girl]

Brother (father of the person)
l
l
l
Brother (uncle) close relative
l
l
l
Sister (aunt) second cousin

[_Lemmie]

Oh look, a calculator.

https://dnapainter.com/tools/sharedcmv4/611

When I enter 609, second cousin shows a probability of 1.53%.

So what exactly is up with Ancestry?

Somebody could step on my head right now and I'd be okay with it.

Meaning it could happen, but relatively unlikely.

So you have an unusual result, but not an impossible one.

[_Jersey Girl]

Meaning it could happen, but relatively unlikely.

So you have an unusual result, but not an impossible one.

Yes, I understand that. Can you think of any reason that the test would produce that unusual result, Lemmie?

Why wouldn't it at least place her as first cousin?

[_Lemmie]

Meaning it could happen, but relatively unlikely.

So you have an unusual result, but not an impossible one.

Yes, I understand that. Can you think of any reason that the test would produce that unusual result, Lemmie?

Why wouldn't it at least place her as first cousin?

Because it didn't. As far as I know, these tests are based on data collected and are estimations. As far as reasons, read below:

When interpreting autosomal DNA statistics, one must be careful to distinguish between the distribution of shared DNA for given relationships and the distribution of relationships for given amounts of shared DNA.

For example, known second cousins on average share 212.5 centiMorgans (cMs), but in extreme cases can actually share as little as 47 cMs or as much as 760 cMs.

https://isogg.org/wiki/Autosomal_DNA_statistics

[_Jersey Girl]

Thanks, Lemmie. I hadn't seen that statement. I don't fully understand the role of algorithms that produce the results.

Here are my thoughts at the moment...

1. They may share a common mother only.
2. They may share a common father only.

The autosomal tests do not make that distinction unless the segment piece (which I'm trying to get) demonstrates that. I suppose the only possible way to solve the problem would be to either do X or Y chromosome tests to sort out which parent they actually share.

I don't know if I'm making logical sense here.

[_Lemmie]

Ok you're not going to like this, but if the half-aunt's other parent was your friend's parent's cousin from a sibling of their grandparent, then the half-aunt and your friend would be second cousins.

I prefer to think it is the vagaries of statistical analysis that gave you that result, however.