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Author Topic: Family Finder vs Y and mT  (Read 1256 times)
Jim Rohrer
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« on: March 23, 2012, 10:40:29 AM »

Maybe this post will get a discussion going. 

Honestly, I don't see how learning about a genetic connection with R1a... from prehistory illuminates my genealogy at all. This does not affect my personal sense of identity. Migrations over time have mixed up the genes a lot over the millenia.  And putting just one branch of my tree in haplogroup does not describe my ancestry over all.

Autosomal DNA is different.  It tells a more recent picture of our ancestry.  It also covers all of your (recent) ancestors, not just one branch.  It can help to fill gaps and correct errors in the family tree.   

Others may have different opinions.
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Jim R
rms2
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« Reply #1 on: March 23, 2012, 07:15:48 PM »

I think all three kinds of testing are valuable. For me, there is an attachment to my surname/y-dna line. I know it's only one line, but it's my father's father's father's father, etc. That means a lot to me. It also means a lot to me to know where that line came from long long ago and what sort of ethnic connection it might have. As SNP discoveries advance, we are also narrowing down the y-dna ancestral geography quite a bit. Not too long ago, when I got my first 37-marker results, all we really knew about R1b was that it is big in Western Europe. Now that we have discovered so many branches, and the twigs off of those branches, we have varieties of R1b that are localized and can be connected to specific regions and peoples.

MtDNA is where I am lacking. I have only the most basic test results from FTDNA, but they have still been revealing. I plan to order the FGS eventually.

I do agree, however, that the Family Finder test is superb and opens up more of a person's pedigree than either y-dna or mtDNA testing.

Because of my attachment to my y-dna line, if I had it to do over again, I would probably still do y-dna testing first and foremost; but I think all three kinds of tests need to be done and that each of them complements the other two.
« Last Edit: March 23, 2012, 07:21:49 PM by rms2 » Logged

Jim Rohrer
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« Reply #2 on: March 25, 2012, 10:50:55 AM »

Rms2-

Concerning the autosomal profile: if I understand it correctly, half of the child's dna comes from each parent.  The dna from each parent is sort of randomly chosen.  So the luck of the draw influences which allele's you end up with, but still the odds are in favor of your profile being representative of your recent ancestry instead of tilted toward one or two atypical strays. 

My family finder results are due in 3 weeks, if they confirm what DNATribes said, then my profile loads heavily on eastern Europe, with hits on Roma, Transylvania, Czech Republic and Poland. 

Is this more likely to mean that a majority of the recent ancestors were eastern European, or that a single very recent ancestor was eastern European?

The autosomal info caused us to rethink some of the assumptions made in the family tree.  It caused us to notice that many of our ancestors came from Lehigh County PA instead of Lancaster.  Lehigh is the original settlement of the Moravians who were Czech religious refugees who originally moved to Saxony before starting their missionary work in America and around the world. 

The other possibility is a little crazier.  My home town was the winter quarters for the big circuses; many of the performers were eastern European. Maybe grandma dated a circus performer.

Which theory is more consistent with the autosomal profile?     
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Jim R
rms2
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« Reply #3 on: March 25, 2012, 03:45:23 PM »

You understand correctly.

I think it more likely that many of your relatively recent ancestors were Eastern European, but, of course, the other alternative is also possible.

My autosomal results were pretty solidly British Isles, which coincides closely with what I know of the surnames and origins in my pedigree.

(Those results also jive well with my y-dna and mtDNA test results.)
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Jim Rohrer
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« Reply #4 on: March 25, 2012, 06:12:20 PM »

Its nice that your data sources tend to confirm each other.  Did you attempt to hand-calculate your own likelihood ratios?  I did that for several populations from public data sets and some found in research articles.  The size of the ratio depends on what you select for your comparison population. 

My wife and I are registered for a conference in the Twin Cities.  I hope to learn more about how to integrate dna info with traditional genealogy.  I am a newbie to genealogy so my best contribution to the family research is likely to be from the dna side.
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Jim R
rms2
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« Reply #5 on: March 26, 2012, 08:40:38 PM »

Its nice that your data sources tend to confirm each other.  Did you attempt to hand-calculate your own likelihood ratios?  I did that for several populations from public data sets and some found in research articles.  The size of the ratio depends on what you select for your comparison population. 

My wife and I are registered for a conference in the Twin Cities.  I hope to learn more about how to integrate dna info with traditional genealogy.  I am a newbie to genealogy so my best contribution to the family research is likely to be from the dna side.

I haven't done that. I'm not sure I could unless I just based it on surnames, because for many of my lines I don't know who the immigrant was or where he and/or she came from.
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Jim Rohrer
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« Reply #6 on: March 26, 2012, 11:03:27 PM »

That's where it gets interesting.  You may match on some populations you don't expect.  But like I said, the selection of a denominator population is tricky.  I am not sure what the rule should be.  Someone said that people with European ancestry share 75% of their genes.  And we share 80% with a grandparent.  So a grandparent is only slightly closer genetically than all other Europeans, if you look at it that way.
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Jim R
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« Reply #7 on: March 30, 2012, 06:47:12 PM »

I'll be glad when FTDNA upgrades Population Finder to provide more resolution, i.e., more sample populations.
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Jim Rohrer
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« Reply #8 on: April 11, 2012, 10:16:20 PM »

Correct me if I am wrong, but it appears that any consideration of European populations prior to the end of the last glacial maximum (ice age) is largely irrelevant because the ice dramatically reduced genetic diversity.  People were pushed into a limited number of livable areas, where they no doubt killed each and inter-married.  As the ice receded, populations could spread northward.  Net result is a lot less genetic diversity in Europe than in continents less affected by the ice.  The subpopulations in Europe, to the extent that they actually are different from other European populations, mostly are post-glacier and so are not as 'deep' in history as some people might like to dig. 

So, maybe we should draw a line in history some time after the end of the ice age (about 15,000 years ago) and say 'deep' ancestry searches should not go any deeper than that line.  Population geneticists who dig deeper might be producing work that is highly speculative or perhaps just plain imaginative. 

Furthermore, the refuges from which the refugees spread northward may define the core dna of later populations.  R1a for example may have originated in the Ukrainian refuge (the coast of the Black Sea).  The other refuges may have been Iberia, Italy, the Balkins,

Then throw in the likelihood that farming did not begin in Europe for another 10,000 years, and you have to conclude that not much worth talking about defined the regional populations in Europe prior to maybe 4000 years ago.
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Jim R
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« Reply #9 on: April 12, 2012, 07:19:26 AM »

Ancient dna findings have the potential to delve pretty deeply into the past. I personally am not so much interested in Ice Age or pre-Ice Age stuff. It doesn't seem likely that my y-haplogroup was even in existence at that time or that its predecessors were even in Europe then.
« Last Edit: April 12, 2012, 07:20:25 AM by rms2 » Logged

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