Before we start, I do not claim to have in depth knowledge of this very complex subject. We have 46 chromosomes or 23 pairs, 22 of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males (Y-DNA) and females (mtDNA). This 23rd pair is what most people/articles (including this one) are referring to when they are talking about DNA and Genealogy. It is important to remember that we are a product of the 23 pairs (100%) not just one pair (4.3%). DNA does change/mutate but the rate is very slow, perhaps once every 10,000 years.
mtDNA(mitochondrial DNA) is passed by mothers to all their children. Males inherit their mothers mtDNA but do not pass it on. mtDNA is a direct line back, mother from grandmother from great grandmother ad infinitum. Useful for general genealogy but is of little use to a one name society as the name would change at every generation.
Y-DNAis passed by fathers to their sons only, never to daughters. Y-DNA is a direct line back, father from grandfather from great grandfather ad infinitum. Y-DNA should follow surnames, therefore Y-DNA is of use to a one name society and for general genealogy. Surnames, for various reasons do change.
My wife's mother was Sylvia Witheridge (b1915) the daughter of John Northmore
Witheridge (b1872) and Mary Jane Knight (b1879) whose mother was Elizabeth Willis.
When considering DNA she is more Knight/Willis than Witheridge as she inherited her
mother's mtDNA but not her father's Y-DNA. However she is her fathers
daughter!
Sylvia had a brother Ivor Witheridge (b 1921) who would have inherited his
mother's mtDNA and his father's Y-DNA thus continuing the Witheridge Y-DNA line
which should match that of other male Witheridge descendants.
As far as we know Ivor did not have any children, thus this Witheridge line has
“Daughtered out” (ended, no more males).
The above example only considers mtDNA and Y-DNA, the 4%. Our 100% DNA comes from both our parents and their parents male and female.
I have had my DNA tested by FamilyTreeDNA (https://www.familytreedna.com), one test for mtDNA the other for Y-DNA. My family lineage, based on personal knowledge and research is English, Welsh and Irish. The results of DNA testing confirm this.
mtDNA- My Haplogroup is H1j. H1 is the most common branch of haplogroup H.
It most likely originated 15-20,000 years ago and represents 30% of people in haplogroup H. In the book "The Seven Daughters of Eve" by Bryan Sykes this would be the clan "Helena" who were the original Celtic inhabitants of Britain.
Clan Helena began about 20,000 year ago in Southern France (Vezere and Dordogne). Quite widespread throughout Europe but more prominent in the Basque population of Spain and France.
If you are related to me through my Mother or her sisters or their grandmother or her sisters etc., then we share the same mtDNA. The female surnames in my line would be Berrisford, Simcock. Yours of course could be different.
Y-DNA- My Haplogroup is R1b R-L48 whose lineage began in Europe.
It is the descendant of the major R-M343 lineage. Though R-L48 has spread across much of Europe, it is more common in Northwestern Europe than elsewhere. Bryan Sykes has named this clan Oisin (pronounced O'Sheen).
R1b is the largest clan in Britain and Ireland linking Celtic Britain with Iberia. Six thousand years ago hunter gathers moved north along the Atlantic coast to Brittany and then to Britain and Ireland. The movement into Britain was early and numerous, the descendants of the Celts form the genetic bedrock of modern Britain.
If you are related to me through my Father or his father etc. or their male siblings then we share the Y-DNA. The male surnames would be Dwyne, Dwine and Downey. The oldest record I have is of Thomas Dwine b1785 Ireland. Of course there could be many other surnames.
DNA can identify related individuals but cannot determine relationships. You inherit half of your DNA from your Mother and half from your Father. A 50% match could be a parent or a sibling. You are 50% similar to your Mother and Father, 25% to a Grandparent. First cousins share 12.5% of their DNA
If you have your DNA tested you can use the search facilities
provided by FamilyTreeDNA (https://www.familytreedna.com) to look for matches. My
search results show quite a few individuals that may be related, several with an
increased probability and one (Hi Jerry) that is almost certainly related. Jerry and I
have almost identical Y-DNA and a similar knowledge linking our male ancestry to
Ireland. We also believe that our common ancestor was born before 1700.
DNA testing is not cheap. It is however a method of tracing your family to a time when
written records did not exist. DNA testing may provide a contact with relatives that
you have no knowledge of.
Other than being a customer I have to connection with FamilyTreeDna.
I am related to Edward the Elder, b872 Wessex
- d924 Cheshire, King of England 899-924
Most will think your nuts, however it's absolutely true
!
In broad geographical areas (Western Europe ect) everyone alive today is related to everyone that was alive in the 10th century. This has been proven through DNA and Mathematics.
Your ancestors do not branch out in a straight line, the line curves, increasing with each generation.