yanceyfamilygenealogy.org
DNA Testing - "Proof" or "Smoke and MIrrors"?
[ click expand post ]
Many people often assume that "a DNA test is a DNA test" - that they are all pretty much the same and inter-comparable.
Then you often have people on two polar sides - some saying "DNA tests are 100% accurate and "DNA doesnt lie " and then you have other people that almost always seem to think "take it all with a grain of salt".
But it really depends - which DNA test one took - and what question (of various possible ones) are being asked.
A few years back members of the Yancey family and Nanney family both took YDNA tests and proved (contrary to family tradition) with virtual 100% accuracy that those tested did NOT have a common paternal ancestor within the last millennia.
(because they were two different Haplotypes) this was a simple $50 test of 12 markers various years back.
On the other hand - some people have take an autosomal test and tried to take the results as proof or probability that the unknown Yancey immigrant of about 1700 - must have come from the British Isles.
(When the DNA from this ancestors in each of us living today, is so small that autosomal testing cannot even come close to telling me where my Yancey immigrant ancestor came from)
For the Yancey Family Researchers I put together this FAQ as it relates to DNA testing
http://yanceyfamilygenealogy.org/dna_faq.htm
DNA tests can answer certain questions with virtual proof, other with levels of probability, and others are simply out of reach - it just depends . . . .
and all the tests are not trying to answer the same questions so make sure you apply the right test to the right question and then understand the rules of probability that apply.
@Yancey/Yancy Family Genealogy
@Nanney Family Genealogy
Comentarios
-
My husband ties to the Nanny family through Griffith Owen, Robert Owen, Jane Vaughn, Robert Vaughn etc.
0 -
then please join us in the Nanney Coummunity Group
https://community.familysearch.org/s/group/0F93A0000009YCmSAM/nanney-family-genealogy
0 -
Agree 100% One must be careful of the DNA data. Taking it beyond that of basic origin is, in my humble opinion, suspect.
0 -
There is very little error if any in the first few generations. In fact the 'errors' are more likely in the low ranges, 10 cM and under or even 20 cM and under. It may be just noise at that point. A cM analysis comparison chart can tell you more for those. Many really are true matches. An easy way to tell is if you have closer matches that match them as well.
Of course I am referring to shared matches not ethnicity. Ethnicity is getting more accurate and can have clues but it leans more to speculative.
If you want to know where some of your long ago ancestors came from then try y-dna. Those findings won't do much to help you find recent matches but they can be interesting and can help you find surname clues or verifications.
0 -
any statement about DNA errors needs to be qualified as to what test and what question is being asked.
I was mainly referring to ethnicity testing
one of the reasons it can never be totally accurate no matter how good the science - is that we dont inherit our genes in equal amount from our different ancestors
the percent ethnicity based on a pedigree chart - even if perfectly accurate - will not match the ethnicity of our genes - because of randomness in inheritance
even two siblings will not inherit the same amount of ethnictiy from their parents - even though they share the same pedigree.
and more importantly - in the end - - DNA is not inherited based on political boundaries. DNA can never prove (all by itself) that a given ancestor lived in given place. although probabiilities can be estimated (very roughly)
0 -
Because of the way the DNA testing companies have focused their advertising on ethnicity ESTIMATES, many people only look at those estimates. They do not even realize that they have matches showing of those that share a common ancestor with you. They look once at their account and never go back to see that they have received messages from those they share DNA with.
I have had terrific luck with identifying matches and where they fit into my tree. I discovered a grouping of matches that did not match up to my tree. After some work in looking for common names and places I soon discovered who these people were. My 'paper grandfather' was not my biological grandfather. With a lot of research I was able to definitively prove who the biological grandfather was.
In another case, I was contacted by a match that lived on the other side of the world. We both knew we had British ancestry but could find no common names but he did not have a posted tree anywhere. So a couple of years later I found a tree he had created. I spend time going through his surnames and happened upon a name I recognized. In searching my home database I could not find that name. However, I was able to globally search my database and found the surname buried in a note I had made for an ancestor. Family stories had told me that this ancestor did not have an identifiable father. Well, my census note showed that my ancestor was living in the same household with my matches ancestor. This was the mid 1800s and I now know who this ancestors parent was.
It does take work but DNA is amazingly well worth the effort.
0 -
Oh so true! My great-grandfather was born in Sicily of both Italian and Albanian heritage (Albanians left Albania in 1400s when the Turks invaded.) The fascinating thing is that my grandfather and father's DNA shows almost exclusively Greek, while my Grandfather's sister shows 35% Italian and almost no Greek. These all based on Ancestry's Autosomal testing. So it has been an interesting comparison...was it just luck of the draw? Do the Greek genes stick to the Y-DNA better than the Italian genes?
0 -
I agree
so many people just think DNA is a magic bullet that will just give you all your answers with hardly any work. - that, it is not - in most cases.
but yes - when coupled with serious traditional research and then comparing that to matches can be powerful.
but all too often people just get confused with the matches and throw up their arms.
0 -
Sue, you have shared great success stories. DNA does take work, but the information that can be gained is amazing. Are you available to help others that need assistance with DNA research?
0 -
DNA is like any other tool. If you do not know how to use it, it just sits in a toolbox or gets overlooked.
I would love to see more discussions with people asking for help understanding their DNA. i suspect that there are many here that could offer suggestions and provide information.
0 -
agreed -- it is a tool
but the fact is so many DNA companies give so very misleading results - just to market their product
that I would even say a majority of people misunderstand and misinterpret their results.
(especially in the area of ethnic/geographic testing results)
0 -
Certainly. I am happy to help where I can.
0 -
I think someone may post a link to her WATO tree soon. I am happy to look at it, but I have a busy schedule this week. I would love it if you could check it out. Is this something that you would feel comfortable doing?
0 -
Ethnicity is improving as more people take tests. My DNA seems to be spot on now. It didn't use to be. It used to feel close, but something was off. I reclaimed an unknown ancestor in the tree and suddenly things seem to be really accurate. I can follow many lines through DNA matches with other people that claim similar ancestors. I am really impressed with what DNA has taught me.
0 -
ethnicity reports will always be off
because your DNA is not a perfect representation of your pedigree - and never will be because we dont inherit our DNA in the same proportions as our pedigree.
for this reason - no matter how many people take the test - and no mater how perfect the science is - it will always be off.
Even siblings can be off as much as 10% from each other. Also the ethnic match is based on matches to living people - and thus doesnt take into consideration - migration patterns across history
and thus cannot prove where any one specific ancestor really lived. Yes DNA matching is great . Im not referring to DNA matching of cousins - what I'm referring to is ethnic/geographic origin reports - that are totally blown out of proportion and interpreted to mean something they dont actually mean.
0
