Does my brother have the same father as me?

[DigitalDragon]

I have reason to believe my brother and I don't have the same father.

I've already taken the Y-37 test and the AncestryDNA test. Is the best way to learn whether we have the same father for my brother to take the Y-37 test? I suspect that my real father is my father's brother. This is a huge question for us. I'll appreciate any suggestions. I've done a lot of genealogy, but I'm just starting to learn about DNA.

[georgian1950]

You would learn more if your brother took the AncestryDNA test.

Remember Y-DNA did not nail Thomas Jefferson (apologists said the brother was the culprit), however autosomal DNA did.

[Gecko]

In this case, it is most likely that all involved would have the same Y-DNA, if your father and your father's brother both have the same father.
Even with your Automal DNA, it's possible for you and your brother to get completely different halves of your fathers Autosomal DNA (even if you do in fact have the same father).

[Biblioteque]

https://dnapainter.com/tools/sharedcmv4


First, your brother needs to do a FF autosomal test at FTDNA.

And then this great tool by Blaine Bettinger should help. It has been spot-on for me. Your shared cMs will help you to determine whether you are full siblings, or half. People can lie, paper can lie but Dna does not lie. You just have to know how to interpret it.

[DigitalDragon]

Thank you, georgian1950, Gecko, and Biblioteque for your replies. What you say makes sense. I'm realizing that my thinking on this has been totally wrong. My sister just last week did the FF test. I suspect I have may have a different father than both my sister and brother. If I'm understanding you correctly, then my sister's FF test compared with my AncestryDNA test could also tell whether we have the same father. Am I correct?

[Jim Barrett]

You, your brother and your sister should all get Family Finder while it is on sale. Of course any of you who already have Family Finder would not need to test again. Add a coupon code to get a better price. Transfers from the new Ancestry don't get as many matches as Family Finder test for the same two people.

DigitalDragon (wish I could use your real name) if you don't have FTDNA's Family Finder you can add it to your Y-DNA kit. They'll use the original sample.

[georgian1950]

You, your brother and your sister should all get Family Finder while it is on sale. Of course any of you who already have Family Finder would not need to test again. Add a coupon code to get a better price. Transfers from the new Ancestry don't get as many matches as Family Finder test for the same two people.

DigitalDragon (wish I could use your real name) if you don't have FTDNA's Family Finder you can add it to your Y-DNA kit. They'll use the original sample.

While the new AncestryDNA kit will pick up close relationships with other vendors kit while not doing so good with more distant matches, the ideal situation would be for everyone in this puzzle to have the same vendor and version of a kit. I agree about going with Family Finder for everyone.

[DigitalDragon]

Thanks Jim and georgian1950. I've been hesitant to use my real name because of family sensitivities. My genealogy research has raised serious questions both about my father's real father and about whether my father is my real father. My grandmother and mother were highly respected women who both suffered terribly in their marriages. I don't want to raise questions among relatives about them.

I transferred my AncestryDNA results to FTDNA in 2017. Apparently I can't take the FF test myself because of having transferred my AncestryDNA results.

[mattn]

You would learn more if your brother took the AncestryDNA test.

Remember Y-DNA did not nail Thomas Jefferson (apologists said the brother was the culprit), however autosomal DNA did.

Do you have a link to this claim? I'm curious how autosomal DNA could differentiate between 2 full brothers that far back in time. Now in DigitalDragon's case yes that is recent enough for autosomal DNA to solve.

DigitalDragon is your AncestryDNA transfer and Y-DNA in different accounts or the same? If 2 different accounts then if you want to test with Family Finder add Family Finder while logged into the account that has the Y-DNA results. If you only have one account with both an AncestryDNA transfer and a Y-DNA result then you will either have to have customer service delete the AncestryDNA transfer for you so you can order Family Finder or you can just create a new account for yourself and add Family Finder to that. As mentioned it is probably best to have everyone tested with the same chip but if money comes into play than comparing your AncestryDNA results to Family Finder results will still give you the answers you are seeking when dealing with the close relationships you are talking about (whether a sibling is a full or half sibling etc.).

[Biblioteque]

DigitalDragon: Yes, just plug in your shared cMs with any match, and the tool will give you a range of possible relationships and the percentages. It is a guide that has been accurate for me. Guess, I should say this has nothing to do with a paternity test per se, and would not hold up in court. It is just a great tool used in genealogy. Please let us know what you find.

[georgian1950]

Do you have a link to this claim? I'm curious how autosomal DNA could differentiate between 2 full brothers that far back in time. Now in DigitalDragon's case yes that is recent enough for autosomal DNA to solve.

Here's a couple:

https://blog.23andme.com/23andme-cus...mas-Jefferson/

https://www.theroot.com/dna-does-not...chy-1790875228

[Gecko]

I'm not 100% convinced that a autosmal (FF / Ancestry) test can definitively prove a father, if the two options are brothers, unless you can also test the possible fathers and / or your mother.
A lot depends on how much DNA each of the possible fathers share as brothers.

[Jim Barrett]

I transferred my AncestryDNA results to FTDNA in 2017. Apparently I can't take the FF test myself because of having transferred my AncestryDNA results.

You are correct, you can't have transferred autosomal and FF in the same kit. I don't remember when Ancestry changed their test. Early 2017 might be okay. You can buy a new kit at FTDNA with FF only. During the current sale you get a good price and reduced P&H.

[georgian1950]

You are correct, you can't have transferred autosomal and FF in the same kit. I don't remember when Ancestry changed their test. Early 2017 might be okay. You can buy a new kit at FTDNA with FF only. During the current sale you get a good price and reduced P&H.

He's already taken a Y-DNA test so his sample should be on file. No need for P&H if the sample on file can be used. My understanding is that the transferred kit needs to be deleted by FTDNA so that the new kit can be ordered under the same ID that the Y-DNA test is under.

I thought that FTDNA had a provision for upgrading a transfer to the actual FF. I definitely would talk with customer service.

[KATM]

Per ISOGG's page for Ancestry, in the Chip Versions section, they started using their version 2 chip in May of 2016. DigitalDragon would need to determine if he tested before that. I think I saw in another thread that he had tested in 2017, but I could be remembering it incorrectly.

It's worth contacting FTDNA to find out if he can delete his Ancestry transfer and order a FF test.