Talk:DNA test

The new text includes


 * Most of your DNA is autosomal/chromosomal DNA...Unfortunately for genealogists, because this DNA is "all mixed up" (recombined) from both parents, it cannot be isolated for genealogical information.


 * While this is true, as far as it goes, autosomal DNA can be used for genealogical purposes too. Its harder to do, but it is often used in a genealogical context when dealing with hereditary diseases.  Those diseases have an hereditary basis because they are linked to a persons genetic code---and unless its a sex linked disease would be described as "autosomal". .  As an example, in southwest Virginia there is a group of people known as the "Blue Fugates".  They have a genetic mutation that leaves them with a dfinite blueish cast to their features.  I understand that this mutation has been pinpointed to a specific individual living in SW VA about the time of the Revolution.  There are many Fugates in the area that lack this mutation, and you can in many cases tell those descended from the original "Blue Fugate" by whether or not they share that trait, or in the case of recessives---whether they carry the gene.  So, in cases such as this, you could in fact use autosomal DNA for purposes of genealogy.


 * There are two types of DNA that are useful for genealogists because they pass almost identically from one generation to the next. Y-DNA only passes from father to son, and mitochondrial DNA (mtDNA) only passes from mothers to her children. Most mt-DNA changes more slowly than Y-DNA over time, and so is more often used for anthropological studies of deep genealogy such as examining the ancient movements of peoples across continents.


 * That leaves the impression that YDNA is not useful for deep genealogy. In fact, its just about equally as useful.  Again, using an example from SW VA, there was a recent test conducted of people said to have Melungeon ancestry.  The Melungeons are a group of people said to have been in SW VA prior to the appearance of the first settlers.  Their origin is something of a mystery (perhaps a self created one).  The popular theory is that they are descendants of conquistador's in the Dom Pardo expedition through the southeast during the 16th century.  Test this theory mtDNA was sampled from a goodly number of self described Melungeons.  The conclusion of the researchers was that apart froma slightly higher percentage of Indian related mtDNA, they were indistinguishable from any other group of settlers in the area.  Something of a downer for those looking for an answer to the question, and since then I've seen almost no activity on the subject.  However---and I'm looking at this from afar, and do not have the original writings on the subject to examine, so I'm somewhat speaking off the top of my head---I really don't understand how a mtDNA test would prove anything.  Exactly who did the researchers think these conquistadors were fathering children on?  Clearly if there were any survivors of the Dom Pardo expedition that went native and reproduced, their children and descendants would be carrying Native American mtDNA, not Spanish or Portugese.  If you wanted to test for traces of European heritage in these Melungeon descendants you want to be looking at YDNA, not mtDNA.

As far as the article is concerned, I'm giving those specific examples only to show that its a bit more complex than is currently described. The article is a good one to have here, but it needs a bit more depth in my opinion. Bill 12:44, 5 September 2007 (UTC)