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MitchellSince1893
01-11-2016, 05:19 AM
Hopefully some knowledgeable member will know the answer to this.


On the FTDNA website they state that a 67 marker test with a GD of 10 or 11 would indicate no MRCA in the last 1000 years. https://www.familytreedna.com/learn/y-dna-testing/y-str/two-men-share-surname-genetic-distance-67-y-chromosome-str-markers-interpreted/

I was curious what is the oldest confirmed MRCA and associated genetic distances between individuals with at least 67 STR marker tests.

So far I've found GD=3 for shared ancestor born in 1690. http://www.jmhartley.com/HBlog/?cat=6

I'm sure there must be much older confirmed examples out there.

For example, are there any confirmed examples of individuals with a MRCA born in the 1200s, 1300s, 1400s? earlier? If so, when was the MRCA born and what is the GD between the individuals?

RCO
01-11-2016, 11:17 PM
In my group I have the following genetic distance - STR - FTDNA markers: 12 - 2, 25 - 4, 37 - 6, 67 - 8, 111 -12. YFull calculated our distance as 1250 ybp analysing our SNPs (Bam file from FGC and Big Y).
http://www.yfull.com/tree/J-M365/

geebee
01-12-2016, 04:24 AM
Unfortunately, at FTDNA I don't have any matches at all for 67 markers, or even 37. However, I did have a 46/46 marker match at Ancestry (back when they were doing Y DNA testing).

It actually was a 47/47 match, because my relative and I matched 3 for 3 on what was normally a two copy marker.

We also happened to have the same unusual surname, which is an Americanization of a German name that was and is rare even in Germany: Bookhammer. Turns out that we're 4th cousins, twice removed. The common ancestor was in fact the man who brought the surname to America, in its German form of Buchhammer. Kinda cool, I thought.

Funny thing is, originally Ancestry was fairly close in its prediction of about 6 generations to the common ancestor. It was actually 7 for me and 5 for my cousin. However, they based this estimate on a 45/46 match. The problem was, they were only showing the first two from the 3-copy marker I mentioned, and they weren't following the rules properly.

They displayed 459a and 459b as 9 and 10 for me, and as 10 and 10 for my cousin. Only, the download file showed 459a, 459b, and 459c as 9,10, and 10 for me; and as 10, 10, and 9 for my cousin! They should have listed both as 9, 10, and 10.

But here's the funny thing. I brought this to their attention, and they corrected the display. But when the GD was changed from 1 to O, it also changed the MRCA prediction from 6 to 1! In other words, they thought we must be brothers! :)

MitchellSince1893
01-12-2016, 04:56 AM
In my group I have the following genetic distance - STR - FTDNA markers: 12 - 2, 25 - 4, 37 - 6, 67 - 8, 111 -12. YFull calculated our distance as 1250 ybp analysing our SNPs (Bam file from FGC and Big Y).
http://www.yfull.com/tree/J-M365/

Thanks for posting. I'm asking because I have a 67 marker match that is a GD = 8 using infinite method (you only count 1 GD for an STR difference even if the values are more than 1 apart) and GD=14 using the hybrid method (total up the total of all STR value differences). He shares a terminal SNP with me so I know he's a valid STR match.

I'm awaiting his results from FGC Y Elite which should be out in mid February.

My guess was our MRCA would be 1250 ybp +/- 500 years.

thetick
01-12-2016, 07:11 AM
GD of 1 -- 66/67 match is common ancestor born 1700. Very confident as there are Mennonite church records confirming both families and the common ancestor
GD of 4 -- 63/67 match we think was born around 1650. This is speculative based on old Swiss Mennonite church records and involves a Swiss -> two similar English name changes but most certainly could be much farther back.

jdean
01-12-2016, 11:57 AM
My closest match is 2 @ 67 and our common ancestor was born in 1733

My most distant surname match is 9 @ 67 and 11 @ 111, both our MDKA ancestors came from Shropshire. My surname ranks in the 2 thousandths and has been recorded in Shropshire as early as 1252.

I can't say when or where our MRCA was born but it must have been earlier than the mid 16th C.

Táltos
01-12-2016, 12:06 PM
jdean and thetick,

How did further SNP testing match up with them? If they further tested them of course. My brother's closest on the STRs are all GD of [email protected] markers. SNPs they are all YP1003. Then two of them went on to have SNPs further downstream of SNP YP1003 that my brother does not have.

Edit-No one can connect to a common ancestor. Everyone has different surnames.

jdean
01-12-2016, 12:13 PM
jdean and thetick,

How did further SNP testing match up with them? If they further tested them of course. My brother's closest on the STRs are all GD of [email protected] markers. SNPs they are all YP1003. Then two of them went on to have SNPs further downstream of SNP YP1003 that my brother does not have.

Edit-No one can connect to a common ancestor. Everyone has different surnames.

We both share the same terminal SNP which my closest none surname match was negative for.

MitchellSince1893
01-12-2016, 02:45 PM
I think folks posting this type of data in this thread could help us eventually get an idea of approximately when STR GDs mostly become unreliable (assuming the matches are on the same SNP branch).

IMO, as the GD increases their utility breaks down (again assuming it's a valid SNP match) The question is, at what point?

For example it may turn out that GD = 6 @ 67 markers may mostly be proven to be within last 1000 years.
While a GD = 10 might be all over the place, e.g. 1000 to 3000 years, as STRs mutate back and forth in values at the same location.

On my own terminal branch with a Yfull estimated MRCA of 3200 ybp, my 2 matches @ 67 marker are GD of 14 and 15 with infinite method, and 17 and 22 using the hybrid method..using the mymcgee.com 111 marker tool.

Using the STR method, the MRCA is listed as 1300 ybp. So if my result is typical, a GD of 14 @67 markers appears to be unreliable in estimating MRCA dates.

Dave-V
01-12-2016, 03:55 PM
Ken Nordtvedt published a paper (http://www.jogg.info/42/files/Nordtvedt.htm) where he proposed that the traditional TMRCA calculation (from Bruce Walsh's paper (http://nitro.biosci.arizona.edu/zdownload/papers/MRCA.pdf)) should be adjusted based on the starting point of the two individuals being compared - the ancestral haplotype of the MRCA, in other words. AFAIK most of the tools out there just use the original calculation. What I like about Nordtvedt's revised formula is that he takes the individual STR mutation rates into account. I've played with his model and (as he says in the paper) it does often extend the TMRCA prediction somewhat farther back into the past.

But as Nordtvedt himself acknowledges, TMRCA calculations are "a fairly blunt tool at best" and their probabilistic nature makes them difficult to apply in genealogical timeframes; it may be that their best value is in assessing degrees of relatedness within a group rather than true TMRCA estimates (in other words, getting more fine-tuned through knowledge of mutation rates than traditional GD calculations would do).

I also think we need a measure of GD that takes "actual" GD into account rather than "apparent" - i.e. as cases of convergence are identified (through SNP testing, presumably) we adjust the GDs to the actual mutations... for instance, if two lines mutate to the same allele value independently, that should still be counted into the GD for TMRCA between them, etc.

thetick
01-12-2016, 09:04 PM
GD of 1 -- 66/67 match is common ancestor born 1700. Very confident as there are Mennonite church records confirming both families and the common ancestor
GD of 4 -- 63/67 match we think was born around 1650. This is speculative based on old Swiss Mennonite church records and involves a Swiss -> two similar English name changes but most certainly could be much farther back.

Note the 63/67 is also a 102/111 match. The 66/67 match never got a 111 test since I had a 111 test already and we know with very high confidence our common ancestor.

I also have a 62/67 match with same terminal SNP. He is no longer responsive and quite angry at my suggestion his paternal line was likely Swiss Mennonite. He wrote a book on his Irish ancestry and appears in my opinion boarder-line obsessed with it.

C J Wyatt III
01-12-2016, 09:36 PM
I also have a 62/67 match with same terminal SNP. He is no longer responsive and quite angry at my suggestion his paternal line was likely Swiss Mennonite. He wrote a book on his Irish ancestry and appears in my opinion boarder-line obsessed with it.

That's funny. Over the past few years, I have come to the conclusion that about 95% of the people who do DNA testing (and especially the experts) are only interested in the results if it shows what they already believe to be the case or what they want to believe. I'll stop before I express more thoughts about sorcerer experts who pronounce results as being good or false with a good bit of theatrics.

I'm a bit frustrated because I have found several places where genealogists have gotten things flat wrong, but it is hard to get any traction with convincing anyone.

Jack Wyatt

Bolgeris
01-12-2016, 10:01 PM
Please see The Bolgeri rare surname only in a valley of Lumbardy..

The progression was as follows
GD between Belgieri and Belgeri:
2/12 - 3/25 - 5/37 - 8/67 - 11/111;

GD between Belgieri and Bolgeri:
3/12 - 5/25 - 7/37 - 8/67 - 12/111;

GD between Belgeri and Bolgeri:
1/12 - 2/25 - 4/37 - 8/67 - 11/111;

Mutations at 12 STR :
DY391 - DYS 385b - DYS439;
Mutations at 25 STR :
DYS449 - DYS464b;
Mutations at 37 STR:
DYS576 - CDY a CDYb;
Mutations at 67 STR:
DYS594 - Dys534 - Dys520 - Dys565;
Mutations at 111 STR:
Dys445 - Dys712 - Dys650 - Dys513 - Dys461;

Total 17 STR mut..var.

Just the fact that we are all L20+ results as SNP has induced to hope.

In comparing Y-DNA111 markers, which show 11 mismatches, the probability that (183488) Belgeri and (N9198) Belgieri shared a common ancestor within the last...

...8 generations is 0.78%.
...12 generations is 12.90%.
...16 generations is 40.91%.
...20 generations is 70.00%.
...24 generations is 88.17%.

* Assuming (183488) Belgeri and (N9198) Belgieri do not share a common ancestor in the last 8 generations

In comparing Y-DNA67 markers, which show 8 mismatches, the probability that (183488) Belgeri and (N9198) Belgieri shared a common ancestor within the last...

...8 generations is 1.35%.
...12 generations is 15.30%.
...16 generations is 40.69%.
...20 generations is 66.15%.
...24 generations is 83.75%.

* Assuming (183488) Belgeri and (N9198) Belgieri do not share a common ancestor in the last 8 generations


In comparing Y-DNA111 markers, which show 11 mismatches, the probability that (183488) Belgeri and (154083) Bolgeri shared a common ancestor within the last...

...8 generations is 0.89%.
...12 generations is 14.21%.
...16 generations is 43.56%.
...20 generations is 72.52%.
...24 generations is 89.68%.

* Assuming (183488) Belgeri and (154083) Bolgeri do not share a common ancestor in the last 8 generations

In comparing Y-DNA67 markers, which show 8 mismatches, the probability that (183488) Belgeri and (154083) Bolgeri shared a common ancestor within the last...

...8 generations is 1.55%.
...12 generations is 16.99%.
...16 generations is 43.75%.
...20 generations is 69.23%.
...24 generations is 85.93%.

* Assuming (183488) Belgeri and (154083) Bolgeri do not share a common ancestor in the last 8 generations.



In comparing Y-DNA111 markers, which show 12 mismatches, the probability that (N9198) Belgieri and (154083) Bolgeri shared a common ancestor within the last...

...8 generations is 0.26%.
...12 generations is 6.11%.
...16 generations is 25.83%.
...20 generations is 54.09%.
...24 generations is 77.61%.

* Assuming (N9198) Belgieri and (154083) Bolgeri do not share a common ancestor in the last 8 generations.

In comparing Y-DNA67 markers, which show 8 mismatches, the probability that (N9198) Belgieri and (154083) Bolgeri shared a common ancestor within the last...

...8 generations is 1.06%.
...12 generations is 12.66%.
...16 generations is 35.58%.
...20 generations is 60.62%.
...24 generations is 79.54%.

* Assuming (N9198) Belgieri and (154083) Bolgeri do not share a common ancestor in the last 8 generations.

Making the calculation that the mutations are 8 on the first 67 STR should be correct to calculate a mutation century.
A common origin 800 years ago?!?
So a MRCA of all us should be at maximum ... the year around 1250 -+ 100 years.. ?
That is the year of birth of surnames in Northern Italy and also the birth of "Bolgeri" surname.

The MRCA of the three Belgeri Belgieri Bolgeri..
should be about 1350 if we see only the Common ancestor of the three family..
May be in the black death... time...
Ciao..

Confirmed now for Yfull.
L
- Subclades statistics
HAPLOGROUP SELECTED SNP KNOWN SNP NOVELS UNROUNDED
AGE (YBP) ROUNDED AGE (YBP) AGE BY ALL SAMPLES (YBP)
− R-Y11785 9 1 8 1467 1450 (750-2700) 1150 (650-1850)
− R-CTS9733 25 17 8 3969 4000 (2600-5700) 3900 (3100-4800)
− R-L20 27 19 8 4282 4300 (2900-6100) 3900 (3400-4500)
− R-Z367 28 20 8 4438 4400 (3000-6300) 4100 (3500-4800)
− R-L2 29 21 8 4595 4600 (3200-6500) 4500 (4000-5000)
− R-U152 29 21 8 4595 4600 (3200-6500) 4500 (4100-4900)
− R-P312 30 22 8 4751 4800 (3300-6700) 4500 (4000-4900)
− R-L151 31 23 8 4908 4900 (3400-6800) 4900 (4500-5400)
− R-L51 38 30 8 6002 6000 (4300-8100) 5800 (5200-6400)
− R-L23 39 31 8 6159 6200 (4500-8300) 6200 (5600-6900)
− R-M269 40 32 8 6315 6300 (4600-8500) 6400 (5500-7300)
− R-P297 94 86 8 14759 14800 (12000-17900) 13600 (12000-15300)
− R-L389 107 99 8 16792 16800 (13900-20100) 16800 (14300-19400)
− R-L278 109 101 8 17105 17100 (14200-20500) 17100 (15300-19000)
FAQ What is YFull's age estimation methodology?

Giuseppe (Joseph) Belgieri

thetick
01-12-2016, 11:22 PM
That's funny. Over the past few years, I have come to the conclusion that about 95% of the people who do DNA testing (and especially the experts) are only interested in the results if it shows what they already believe to be the case or what they want to believe. I'll stop before I express more thoughts about sorcerer experts who pronounce results as being good or false with a good bit of theatrics.

I'm a bit frustrated because I have found several places where genealogists have gotten things flat wrong, but it is hard to get any traction with convincing anyone.

Jack Wyatt

I would not say 95% but certainly a large percentage are extremely passionate to the degree of obsessive. I have observed many test DNA to "prove" or "disprove" a story with all varying degrees of understanding of DNA results. It always a bad thing as there are many L21 folks that have their terminal SNPs down to genealogical families...the Holy Grail of Y-DNA.

MitchellSince1893
01-13-2016, 12:02 AM
EDIT: Removing my tangent from the primary focus of this thread.

I know it's still early in the process but currently we have a couple of examples where GD=8 @ 67 markers has provided confirmed/credible matches up 1250 and 1350 ybp, while GD 14 (in my case) has not. Another had a GD=9 that may have gone back to 700 ybp.

Anybody else have a GD=8/9/10/11/12/13 @67 markers confirmed match?