To help understand some basic DNA analysis go to the page called Understanding Haplogroups. If you and another person have different haplogroups, your are definitely unrelated. Beyond
Haplogroups your next concern is the repetition numbers associated with each DYS Marker or locii.
When I took my DNA test I was the first and only Barnett in the database. In addition, at that time 25 markers
was the most markers FTDNA tested. They now test up to 67.
When I received my results report I found I had a 12/12 match with a man named Pring. Further down in the report it said there a 23/25 match with the
same person. It also said I had a 24/25 match with a man named Maxwell and three 23/25 matches with other men named Maxwell.
I wrote each of my matches and we quized one another to see how we matched one
another. As it turned out we all had surnames different from one another and according to the science we were related probably at some time 600-800 years or more ago in a timeframe we would never be able to discover
our relationship in a historical or genealogical timeframe.
Following is an article published in the June 2003 Family Tree Newsletter. It helped me better understand my results.
By reading the article
below and other articles I have read I surmise I am related to these people possibly several thousand years ago but not in a research traceable historical period. Talk about De J'e Vu!
In addition to the
article below Family Tree DNA has posted two excellent charts which will help understand relationships and marker results
For 12 Marker results
For 25 Marker results-
For 37 Marker results-
For 67 Marker results
Understanding Your Results: Are We Related?
Some Family Tree DNA
customers will have Y DNA 12 Marker Exact matches with other surnames, and on a rare occasion, a 25 Marker Exact match with another surname. Most likely these people are not related in a genealogical time frame.
To understand how this situation occurs, we start by looking at the population before the origin of Surnames. Before the adoption of Surnames, there existed various Y DNA 12 Marker and 25 Marker results in the
male population. The quantity of persons with any particular Y DNA result varied, based on their success of having male children, the survival of the male children, and how many of the male children procreated more
male children. Th
ere was also migrations throughout the world. In addition, during this time, Markers continued to mutate, just as they do today.
Surnames began to be introduced and adopted at
different rates in different countries, typically with the upper classes adopting surnames initially.
Different persons through out a region of the world population would have had the same 12 Marker result at
the time of the introduction of surnames. This situation would have occurred due to some of the people being related and the others as a result of Convergence.
For more information on Convergence, see the
Facts and Genes Vol. 1, Issue 5, the article titled "Haplotypes: Convergence".
As the adoption of surnames occurred,
different persons with the same 12 Marker result most likely adopted different surnames. For example, perhaps there was a person in London who adopted the surname Barker and another person existed in Scotland with
the same 12 Marker result, and they adopted the surname MacGregor. Assuming that there were no mutations, the descendents today would have a 12 Marker exact match, but they are not related in a genealogical time
The key element in evaluating 12/12 Matches and 25/25 matches is the time frame. We are all related at one point in time. For our family history research, we are most likely only interested in a
genealogical time frame. The genealogical time frame most likely does not start before the adoption of surnames, so the first requirement to determine relatedness is the surname.
The Marker mutation rate does
not care about surnames, or whether the person even had a surname. Markers mutated before surnames and after the adoption of surnames. By utilizing the criteria of surnames, you are establishing the time frame for
If two people match 12/12 or 25/25 and the surname matches or is a variant, then they are probably related since the time of the adoption of the surname. If two people match 12/12 or
25/25, and the surname does not match, they are most likely related before the adoption of surnames. (This statement excludes adoption, and extra marital events.) Being related before the adoption of surnames is
probably not relevant to those doing family history research, so matches with others of different surnames are ignored. When two people match and share the same surname, they would be related since the time of the
adoption of the surname.
Scientifically, the probability that two people are related is the same on a 12 Marker match and a 25 Marker match, 99% probability that they are related. The question then becomes
WHEN the relatedness occurred. A 25 Marker match has a smaller window of 1200 years, while the 12 Marker match has a much larger window of 2500 years.
The surname effects the time frame for when they are
related. When the surname matches, the time frame is shortened, so the two people are related since the adoption of the surname. From a genealogical perspective, determining the first recorded instance of the
surname would put a time frame for the adoption of the surname, even though it could have been used prior to that even, but not recorded or the documents lost or destroyed.
Matches with other surnames can
occur for anyone, with any 12 Marker or 25 Marker result, who belong to any Haplogroup. We happen to observe this situation occurring more frequently with those who belong to Haplogroup R1b, since this Haplogroup
comprises a large percentage of the European population and their descendents.
Most matches with other surnames are not worth investigating. 12 Marker results, called Haplotypes, began evolving and mutating
with the first Humans. The time frame for relatedness is a relevant factor, and surnames establish a time frame.