DNA testing and genealogy

BiItalianBro

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My baby brother stopped by my house on Sunday to warn me that I would get a package delivery sometime this week from a DNA testing company. :confused:
Apparently he will submit an oral swab and in about 6 weeks, he will get an analysis of our Y and mtDNA that will track our racial lineage and migratory patterns back about 1,500 years....for around 600 bucks.

I am curious to see just what things about a bloodline one may find out. I assume that despite the HUGE physical differences with my brother (he is 6ft3, pale, smooth and blonde...i am, well..short, dark and hairy) that our genetic code is the same.

Anyone eve done this?? Was it worth it?
 

D_Earlsomme Eatsprick

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the genetic code is the same in all alive organisms: non only you and your brother share the same genetic code, but also you and a fly. Or a worm; in fact, it is the most important proof for the common philogenetic origins of the life. Tecnically speacking, it is the corrispondence between three elements of DNA sequence and an aminoacid.
What varies among organisms and individuals are genetic sequences. Sure they are different between you and your brother, because despite the "source" is the same (your parents), the possible combinations are different. You are the result of just one of them.
 

Pitbull

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My sister is big into this stuff.

There was a recent segment on Oprah and it included a special offer for Oprah which was $200 (Regular price $400) so the $600 seems steep.
(Special pricing is over - Sorry)

Because I told my sister her lack of a Y chromosome would leave some gaps in her report she told me I HAD TO get tested.

Have ordered but not done and she hasn't gotten her results.

There are disclaimers that come with most of them that you may find out things totally unexpected.

Like suppose you and your brother are only 1/2 brothers?

There are some TV shows spotlighting this and it is fascinating.
PBS has one with Henry Louis Gates.
Faces of America | PBS

Gates did 2 earlier series on African Americans - African American Lives and African American Lives 2
http://www.pbs.org/wnet/aalives/

(Sorry I can't find a link for the original - only #2 - However the original is readily available in DVD)
 
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STYLYUNG

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National Geographic Magazine has had an e-mail ad that they call Genographic. A DNA study of either of ones' paternal of maternal lines of ancestors---not just back to great garandparents but back for hundreds of years. The cost for the DNA kit was listed at $99.00. I do not recall that there was a time limit on the offer. If you are a National Geographic subscriber, check you e-mail to see if you received the offer. You will need your account number which is on your subscription billing.
 

AquaEyes11010

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There's something that seems to not be often said when discussing analysis of mitochondrial DNA and/or Y-chromosome DNA: you are finding out about only a small percentage of your ancestors. Let's start with an individual male named Tom (so that we can follow Y-chromosome inheritance as well as mDNA). Tom inherited all of his mDNA and one half of his chromosomes from his mother, and the other half of his chromosomes (including his Y-chromosome) from his father. OK, so we have something from each parent. Now let's go back a generation.

Tom's father got his Y-chromosome from his own father, i.e. Tom's paternal grandfather. Tom's father's mother contributed her mDNA to Tom's father, but since males don't pass on mDNA, Tom won't show any trace of his paternal grandmother's side in his own mDNA, and since she didn't have a Y-chromosome to pass down, nor will her side show up in an analysis of that. While he does have approximately 25% of her genes elsewhere in his genetic make-up, testing for mDNA and Y-chromosome DNA will show nothing from her line. That's 25% not being shown.

Similarly, Tom's mother's father (his maternal grandfather) did not contribute mDNA to Tom's mother, nor a Y-chromosome (if he did, Tom's mother would be male). So testing Tom's Y-chromosome or mDNA would ignore another 25% of of Tom's inheritance. Going back to just grandparents, we're ignoring 50% of Tom's ancestors.

Each generation you go back in time, you lose ancestors contributing to the genes being analyzed. The mDNA and Y-chromosome Tom has can be traced only in two unbroken lines of descent (one going back through his mother's mother's mother's mother's...mother, and one through his father's father's father's father's...father). The way to represent this numerically for each test is 1 divided by 2 to the power of the number of generations back. Go ten generations back, and a Y-chromosome test looks at 1/1024 of your ancestry. Same amount for mDNA. Go back further and the contribution gets tinier. So if Tom finds out that his Y-chromosome has been traced to China 50 generations back, it refers to 1/1,125,899,906,842,624 of his ancestry. If his mDNA was traced the same 50 generations back to Norway, that's another 1/1,125,899,906,842,624 of his ancestry. Each bit is 0.000000000000089% ancestral contribution. If you paid money to find out "where you came from" and got this information, what are you really finding out?
 

D_Harvey Schmeckel

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The most interesting aspect of DNA testing is autosomal, which provides percentages of European, African, and Asian ancestry (Native American being a separate category from Asian in some tests but not others.) Y and mitochondrial results are far more reliable but give only a sliver of the whole picture. Autosomal is much less reliable on percentages from different continents (wide variations between different tests whereas Y and mitochondrial results are exactly the same from company to company) but especially interesting in showing your closest matches in global populations. You get vast amounts of medical risk factor info from some companies along with the genealogical info. Based on historical records, all I knew was that some colonial era ancestors were "free mulatto" although they were all "white" in censuses from 1790 on. DNA testing enabled me to establish that both Native American and African elements are present in the mix, which was very valuable information.
 
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BiItalianBro

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Thanks for the feedback all =). Apparently, this test is both mitochondrial and Y chromo...and both of my brothers are full blood brothers lol.

On an interesting/scary note: starting Friday you can purchase a DNA analysis kit at WALLGREENS (of all places) that will pinpoint genetic markers for cancer, depression, Alzheimers, obesity, diabetes and life expectancy!!
 

Viking_UK

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I had my Y chromosome analysis done about a year ago as part of research for a TV show. The results came back saying my father's side of the family were Scandi, which I already knew, but it's nice to have confirmation.

I'd love to do a full auotsomal analysis one of these days, but that's down the list of spending priorities for now, so it will have to wait a while.

Certainly in this country, it's rare for immediate family members to be involved in these types of studies because of the risk of unexpected differences in results - for example, your dad finding out that he only fathered one child out of the three he raised - which can be a bit traumatic for all concerned.
 

Pitbull

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How cool! Do you have a link?

I'd test my two surviving grandparents. :smile:

https://www.23andme.com/

This is the company the had the "Oprah special". They were featured on her show when she had Henry Louis Gates who hosts the PBS series I mentioned a few posts back. It is the company Gates used to do the testing for his show.
 

D_Harvey Schmeckel

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Another company with the same range of tests as 23andme is:
www.decodeme.com

They were offering free analysis of scores from 23andme a while back, which I jumped on immediately. 23andme is a lot more conservative in admixture estimates, 1% non- European for me vs. 7% at decodeme and 6% at DNAPrint.

On edit, will add that 23andme has a fascinating relative finder service, where you are notified of potential cousins based on DNA, and then can opt to share genealogical info to find the common ancestor.
 
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petite

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Do they only test the Y chromosome? I know very little about testing lineal heritage using DNA testing. All my knowledge is disease and trait inheritance based.
 

Drifterwood

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Do they only test the Y chromosome? I know very little about testing lineal heritage using DNA testing. All my knowledge is disease and trait inheritance based.

The Y is the easiest because it is a straight ( :cool: ) line of paternity whatever you may have thought to be the case.

X is exponential because we all inherit the X from both parents, male and female. I have another kit to do this but haven't as yet. Basically, we're all related which is nice to know. And yes it does go back well beyond Noah.
 

D_Harvey Schmeckel

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The sites explain the differences. Men have the advantage of being able to test for both Y and mitochondrial haplogroups whereas women can only take the latter. But those are just two ancestral lines out of thousands. It's easier to find relatives and test genealogical hypotheses with Y testing than mitochondrial.
Here are explanations of those two from decodeme:
http://www.decodeme.com/maternal-line
http://www.decodeme.com/paternal-line

Ancestry DNA Test | Trace your Ancestors with Genetic Testing | Build your Family Tree | deCODEme
But it's the rest of the information, all the global population matches, medical risk factor analyses, admixture estimates, that make the full autosomal+y+mt testing de rigueur. You can see the same range of services at 23andme:
https://www.23andme.com/ancestry/
https://www.23andme.com/health/
 
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Pitbull

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Do they only test the Y chromosome? I know very little about testing lineal heritage using DNA testing. All my knowledge is disease and trait inheritance based.

No.
They run tests on all chromosomes and mitochondrial DNA (which is passed from the mother)
They cannot do Y chromosome analysis on women (because they do not have a Y chromosome)

The 23andme website leaves something to be desired in how they explain what exactly they are doing.
Mainly they use the DNA to tell you where your ancestors came from and what percent.
For example African American scholar Henry Louis Gates found out he was 50% African and 50% Irish.
Using his mitochondrial DNA they told him he was descended from an Irish King from the 4th Century.

They have a way of figuring out if you are related to certain individuals withing 5 generations.

After my test results are in you could find out that your cousin is a Pitbull. :biggrin1:
 
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No.
They run tests on all chromosomes and mitochondrial DNA (which is passed from the mother)
They cannot do Y chromosome analysis on women (because they do not have a Y chromosome)

The 23andme website leaves something to be desired in how they explain what exactly they are doing.
Mainly they use the DNA to tell you where your ancestors came from and what percent.
For example African American scholar Henry Louis Gates found out he was 50% African and 50% Irish.
Using his mitochondrial DNA they told him he was descended from an Irish King from the 4th Century.

They have a way of figuring out if you are related to certain individuals withing 5 generations.

After my test results are in you could find out that your cousin is a Pitbull. :biggrin1:
EVERYONE claims to be descended from an Irish of some sort.Which is a neat trick considering Ireland do not have records that go back that far!!!
 

Pitbull

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EVERYONE claims to be descended from an Irish of some sort.Which is a neat trick considering Ireland do not have records that go back that far!!!


Yup.
We Irish are tricky - especially when mixed with other people so we become unrecognizable.

Actually there are records that go back very far - DNA!
Being an isolated island helps keep some uniqueness to the genes which allow the scientists to figure this stuff out.
 

molotovmuffin

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Tomorrow I'll go into full detail but for now dna testing for genealogy is done using only one chromosome and checks from 12 up to 64 or 72 allels. Ydna traces your fathers fathers line while mitichondrial does your mothers mothers. Some allels mutate faster than others.

I run the auman orman surname dna project threw familytreedna.

I'm posting from my phone but will get you the info you want with links tomorrow.