Posts tagged ‘mtDNA’

August 25, 2014

Genealogy Consanguinity & DNA — #Genealogy #DNA #Kinship

by C. Michael Eliasz-Solomon

Genealogy_Consanguinity
Consanguinity Chart Now … by John J. Tierney used via CC rights

 This is a beautiful data visualization tool of “relatedness” (Consanguinity) between yourself and an ancestor/descendant. Stanczyk loves good #STEM.  Mr. Tierney modified his excellent chart to add, “What percentage of DNA do you share with your family members”.

Kinship is characterized by the sharing of a common ancestor(s).  Consanguinity is derived from its Latin root:   consanguineous ∴  “of common blood”.

Today, I wanted to use this excellent chart to talk about the three types of Genealogical DNA tests:

 mtDNA

Y-DNA

autosomal DNA

mtDNA / Y-DNA

This way a genealogist can determine for him/her-self what benefit each type of DNA testing offers. mtDNA is for tracing the matrilineal line (your mother/maternal side). Y-Chromosome is for tracing your patrilineal line (aka surname tracing) or your father’s side. These two dnas are for tracing direct descent as these sex-based chromosomes are copied identically from one generation to the next, not half/half as the autosomal dna chromosome’s dna. Correctly, said the mutations in mtDNA and Y-DNA are more infrequent than the non-sex based genome (i.e. autosome) and they are not mixed like the other 22 chromosome’s dna. If you follow the blue arrows (in the diagram) up/down your family tree that is your linear descent; so you mtDNA to trace your mother’s side and use YDNA to trace your father’s side to your proverbial mitochondrial-Eve or your Y-Adam. You are testing for the blue boxes in our diagram.

So what is autosomal DNA?

Genealogy_Consanguinity_dna1

Inside Red Lines – are autosomal DNA generations.

The autosomal DNA are the dna from the other 22 non-sex chromosomes pairs. Autosomal DNA testing is a genealogical DNA test that uses either autosomal STRs or autosomal SNPs. (STR’s are Short Tandem Repeats; SNPs are single-nucleotide polymorphisms.) However, testing companies do not currently offer autosomal STRs tests that use enough STR markers for genealogy. The preferred choice for both genealogy and ethnic population matching is microarray chips that use hundreds of thousands of autosomal SNPs.

Mathematically, speaking you need at least six generations back before you get enough certainty(99% certainty) to do matching to find distant cousins by using current Genealogical DNA testing. So if you do not have your 4x-great-grandparents’ (all 64 of them) surnames then you are NOT guaranteed to be able to use current DNA tests to determine your relatedness to another genealogist (and his/her ancestors who must also have six generations in their tree too).

I am thinking we are still one or two generations (35-70 years) away from using this as a viable technique that will work with any two random genealogists — mathematically speaking. Obvious exceptions are Icelandiks or Amish or other relatively closed-genetic populations who may have greater success (or counter-intuitively lesser) with fewer generations. Its all in the DNA and in the quality of the testing to catch the diversity in your genome.

You will notice that the fine chart we have been using, including the one with the red-lines (my lines) that indicate autosomal DNA testing candidates, does NOT show enough generations. It would need to be extended one more generation. So we need the surnames of 64 people with whom we only share 1.5675% of our DNA with. That is with direct descent. If we are matching to the autosome DNA  (i.e. our Nth cousin, M-times removed) then we are matching to someone who we may only share 0.0243% blood with. That is 2/100th of 1 percent !

Related Blog Article

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p style=”text-align:justify;”>Violinist’s Thumb24-January-2014 – This has many great links to other articles and includes some pertinent facts on DNA to think about. A Guaranteed thought provoker of a blog.

August 8, 2014

King Richard III, died August 22, 1485, buried Saturday, March 28, 2015 — #Genealogy, #Royalty

by C. Michael Eliasz-Solomon

RichardIII

King Richard III was dead, you must admit for over 100 years or this story will make no sense. So more than a century had expired before the bard ever gave him the tragedy treatment.  King Richard III ‘s reputation was such a cesspool  of swirling accusations and counter claims that by Shakespeare’s time he is portrayed as “a physically deformed machiavellian villain, albeit courageous and witty …”. Now it is indeed true that king died in battle (final and decisive battle of the War of Roses) and was hastily buried and his remains were lost for just over a half-millenia.

Richard III was lost and spent the the first 500+ years of his eternal life, ignominiously buried beneath a parking lot in Leicester. They (the Brits) finally located where his bones were and the bones were unearthed in 2012 . Even though they had to ascertain whose bones were unearthed in that parking lot, this re-commenced a less violent and less heroic struggle for Richard III ‘s bones. After half a millenia in the ground we developed the ability look at DNA and via mtDNA and compared to those of a direct descendant of Richard’s sister. So now we have the remains of King Richard III for certain and as I foreshadowed the forces  of several armies immediately sought to lay claim to the bones. This mayhem precipitated a judicial review. The magistrates have ruled and now a proper party, er, um, ahem,  burial will be had and Richard III will be interred Saturday, March 28, 2015 at the Leicester Cathedral. There the king will lie in repose for three days prior to beginning the next part of his eternal life. King Richard III’s remains will lie in repose for three days, during which time the public can pay their respects. The first service, on March 26, will be followed by similar events on March 27 and 28 leaving plenty of time for people to plan their vacations to be a part of this august ceremony and  be able to purchase all of the bric-a-brac that is incumbent at major genealogical events !

Now we come to the heart of the matter for this jester. I  inveigle all of my Anglo-Genealogists and Royalists of all stripes to properly update their family trees to show the accurate burial date and place of poor Richard III. The king’s remains will now be deposited  inside a lead ossuary placed inside an English-oak coffin — all of which will be placed inside a brick-lined vault in the cathedral floor of  Leicester Cathedral. Let the Wikipedia editors take note too!

So let it be written.

#AccuracyInGenealogy

P.S.  —  As the picture shows, Shakespeare was at least correct in the physical deformity part of his portrayal.


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