Genetic distance issues

[jkuehn8]

FTDNA Entered Data Loss

Re-posted this Thread per dna's suggestion

Is there any way to save the 'data' entered online, (Profile, Stories, Notes, and Images, etc.) prior to a Gedcom update/overwrite?

If ALL is LOST, then that WOULD be a SEVERE deterrent to doing anything online with the FTDNA Tree, except upload and look.

Unless we could export from the FTDNA Tree, as a Gedcom, or Data file, WITH all of the additions.

John K -- Batch 586 BigY results RECIEVED 09 OCT 2014, Awaiting access to my BAM Raw Data. Case {180973}

[Hneel]

We understand your question, and it has been answered. FTDNA does not display very distant matches, because they are not genealogically relevant. ysearch lets you see them, but they still are not genealogically relevant.

Well , isn't that the question. I've seen an example of a GD of 5 (@37) of people with the same ancestor from 1569. This one won't show in the match list on FTDNA.

On the other hand: the Family Finder autosomal match list shows results that are far more speculative.

[ERHill66]

Option

I didn't read all the post and this might have been mentioned. There are option we have to check. I found a match at Ysearch who tested here. He doesn't show up on the 12, 25, 37 marker level but does show up at 67. I had only tested to 37 when I found him at Ysearch. He shared the same last name as all my matches so I wondered why he did not show up. I wondered if I tested to 67 would he show up as a match and he did.

Its been awhile since I did the test but I think I remember option like show only people who share the same last name and or who have tested to what ever level you want them to.

[susan_dakin]

I will try to make it clearer.

Me and person A ...........both have done 67 marker test.
In ftdna we are 0 GD
In ysearch we are 15 GD

me and person B ........B only tested to 37 markers.
In ftdna we are 0 GD
In ysearch we are 5 GD

we have a problem,

Clearly ftdna do not indicate and ignore my 67 to 67 , 37 to 37, 25 to 25 with matching test with me and person A ......why? ........it is a false reading of zero GD .

We understand your question, and it has been answered. FTDNA does not display very distant matches, because they are not genealogically relevant. ysearch lets you see them, but they still are not genealogically relevant.

[fmoakes]

Here is an example of two GD 5s. The probability calculations at the listed generations are different due to mutation rates of the different markers involved in each of the 5 mismatches. Note Kit # 34795 is involved in each case and the Distantance numbers are integers.

In comparing Y-DNA111 markers, which show 5 mismatches, the probability that (34795) and (299153) shared a common ancestor within the last...

...4 generations is 12.40%.
...8 generations is 61.13%.
...12 generations is 90.48%.
...16 generations is 98.38%.
...20 generations is 99.78%.
...24 generations is 99.97%.

In comparing Y-DNA111 markers, which show 5 mismatches, the probability that (34795) and (242728) shared a common ancestor within the last...

...4 generations is 11.98%.
...8 generations is 60.14%.
...12 generations is 89.96%.
...16 generations is 98.24%.
...20 generations is 99.76%.
...24 generations is 99.97%.

[dna]

I would like to see what ftdna calculate for only 1 different STR which is more than 1 point in difference.

I can see, on Y-DNA Genetic Distance in my project, that they are using the differences in STR values.

I have verified that using abacus and Y-DNA Results Colorized page. That worked for genetic distances of up to 25. My members have done Y-67 tests and the maximum difference in STR values on one of the hot markers was 4.

[Bartot]

In the Learning Center. https://www.familytreedna.com/learn/...etic-distance/

thanks

the link does not show which method they use.

I would like to see what ftdna calculate for only 1 different STR which is more than 1 point in difference.

[Bartot]

I believe FTDNA use a "modified step method", meaning that if two persons have 20 and 23 as you write it depends on the STR how much this difference will contribute to GD. If it's a very unstable STR that has very fluctuating values from generation to generation at least they should only "rate" that difference as 1 when adding GD. If it's a marker that usually keeps its value from generation to generation and mutations are unfrequent, 3 should be added to GD.

I haven't read any official statement from FTDNA if they use this method or not, only second-/third-hand info that it is how they calculate.

So, would the "red" marked DYS in the projects which represent the fast mutating ones get a different rating?.... and due to this fast mutating , ftdna treat it as a infinite GD instead of a step GD?

[Bartot]

Have you compared the marker values for A & B to yourself on Ysearch to get an idea of the genetic distance?

yes, in ftdna its 0 , in ysearch its 15

Have you compared the marker values for A & B to yourself on a FTDNA site to get an idea of the genetic distance?

see above

Do the marker values between FTDNA and Ysearch agree for all three of you?

no

[Táltos]

thanks

now, in the past Ftdna had 2 systems for GD
Infinite method and step method

Infinite method was 1 GD difference for every STR which did not match.
Step method was how much difference or each STR gave you a GD.

example: person A and B tested each for 37 markers.
A and B had exactly the same numbers for 36 markers
marker ( example) DYS390 was 20 for A person and 23 for B person.
The infinite method would indicate a GD of 1
The step method would indicate a GD of 3

I know Ftdna used both methods at the same....which method do they use know for matches in Ydna?

In the Learning Center. https://www.familytreedna.com/learn/...etic-distance/

[tommypeters]

I believe FTDNA use a "modified step method", meaning that if two persons have 20 and 23 as you write it depends on the STR how much this difference will contribute to GD. If it's a very unstable STR that has very fluctuating values from generation to generation at least they should only "rate" that difference as 1 when adding GD. If it's a marker that usually keeps its value from generation to generation and mutations are unfrequent, 3 should be added to GD.

I haven't read any official statement from FTDNA if they use this method or not, only second-/third-hand info that it is how they calculate.

[Jim Barrett]

I will try to make it clearer.

Me and person A ...........both have done 67 marker test.
In ftdna we are 0 GD
In ysearch we are 15 GD

me and person B ........B only tested to 37 markers.
In ftdna we are 0 GD
In ysearch we are 5 GD

While at ysearch, they must include all 67 STRs and state I have a 15 GD with person A.

Have you compared the marker values for A & B to yourself on Ysearch to get an idea of the genetic distance?

Have you compared the marker values for A & B to yourself on a FTDNA site to get an idea of the genetic distance?

Do the marker values between FTDNA and Ysearch agree for all three of you?

If the three of you are in a common project you should be able to see the marker values. If not you could request that A & B send you a copy of their values.

If the values aren't the same on FTDNA and Ysearch that could account for the difference.

[Bartot]

If I understand what you are saying. You and person A match 12 of 12 markers.

But they don't show up as a match at 25 markers, 37 markers or 67 markers.

If I got the above right then it's quite simple to explain.

For the 25 markers, you have 3 or more differences so they won't show up. i.e. you and person A have 3 or more differences on markers 13 to 25

For the 37 markers you have 5 or more differences between marker 13 and 37.

For the 67 markers you have 7 or more differences between marker 13 and 67.

Thus person A is not a close match to you.

I have hundreds of 12 marker matches with 0 GD. None of these match me at 37, 67, or 111 markers.

thanks

now, in the past Ftdna had 2 systems for GD
Infinite method and step method

Infinite method was 1 GD difference for every STR which did not match.
Step method was how much difference or each STR gave you a GD.

example: person A and B tested each for 37 markers.
A and B had exactly the same numbers for 36 markers
marker ( example) DYS390 was 20 for A person and 23 for B person.
The infinite method would indicate a GD of 1
The step method would indicate a GD of 3

I know Ftdna used both methods at the same....which method do they use know for matches in Ydna?

[MitchellSince1893]

my Ftdna site

it does not show a match when I run only 67 marker , or 37 or 25

If I understand what you are saying. You and person A match 12 of 12 markers.

But they don't show up as a match at 25 markers, 37 markers or 67 markers.

If I got the above right then it's quite simple to explain.

For the 25 markers, you have 3 or more differences so they won't show up. i.e. you and person A have 3 or more differences on markers 13 to 25

For the 37 markers you have 5 or more differences between marker 13 and 37.

For the 67 markers you have 7 or more differences between marker 13 and 67.

Thus person A is not a close match to you.

I have hundreds of 12 marker matches with 0 GD. None of these match me at 37, 67, or 111 markers.

[Bartot]

I'm not sure I understand your query.

You have a 0 GD with someone at 12 markers.
At 67 markers you do not show up as a match with this person on the FTDNA site. At ysearch you show up as a GD 15 with this person.
Is that correct?
A match with someone with a GD of 15 at 67 markers will not show up at FTDNA. It is not considered a match representing a connection in a genealogical time period.

FTDNA will only show GD of 7 (I think) at 67 markers, as above 60/67 is not considered a close match. They match up to GD 10 on 111 markers. (If FTDNA didn't have a cut off somewhere we would have matches with 1000s of men that are meaningless.)

At ysearch you can look for matches further afield, to investigate matches that fall out of the "Close match" that FTDNA report.
This is why FTDNA encourage you to upload your results to ysearch.

Ysearch is supported by FTDNA, they set it up initially.
The only difference is maybe one uses Infinite Allele and the other Hybrid mutations to calculate the GD. (I'm not sure what Ysearch uses these days)

Your FTDNA personal match page will go back to the closest match at a given level, in your case you obviously do not have a close match at 67, 37 or 25 markers with this man and he only shows up in the 12 markers match list.

FTDNA used to have a page that explained the GD and the closeness of matches, But with all their new improved Webpages and designs, I can't find it anywhere, No wonder people new to this can't find it either.

I will try to make it clearer.

Me and person A ...........both have done 67 marker test.
In ftdna we are 0 GD
In ysearch we are 15 GD

me and person B ........B only tested to 37 markers.
In ftdna we are 0 GD
In ysearch we are 5 GD

we have a problem,

Clearly ftdna do not indicate and ignore my 67 to 67 , 37 to 37, 25 to 25 with matching test with me and person A ......why? ........it is a false reading of zero GD .

While at ysearch, they must include all 67 STRs and state I have a 15 GD with person A.

there is a problem if A and B persons in ftdna have zero GD with me , while in Ysearch they have 15 and 5 GD respectively with me