In Memoriam:
Vester Washington Vance (1933-2005)
Russell Kenneth Vance (1917-2006)
Waid Winston Vance (1923-2009)
Willie Doyle Vance (1926-2010)
   

Introduction to Genetic Genealogy

Basic Intro to DNA
DNA (Deoxyribonucleic acid) is located inside every cell of every living organism and contains the genetic blueprint for that organism. It contains a series of bases – adenine, thymine, cytosine and guanine – in paired sequences, adenine always paired with thymine, and cytosine with guanine. The sequence of these base pairs constitutes our genetic blueprint, being essentially instructions on how to make the various proteins which are the basic building blocks of our body.

Our DNA is packaged on our chromosomes, located in the nuclei of our cells. The human genome contains 23 pairs of chromosomes, each pair consisting of one chromosome from an individual’s father and one from an individual’s mother. Twenty-two of these chromosome pairs are known as autosomes, and contain most of the genetic information in our genome. In the Vance DNA Project we do not test the autosomes. We are instead interested in the 23rd pair of chromosomes, those which determine an individual’s sex.

There are two sex chromosomes – the X chromosome and the Y chromosome. Every female has two X chromosomes. Every male has one X chromosome and one Y chromosome. When conceived, every embryo therefore automatically receives one X chromosome from its mother. If an embryo receives the father’s X chromosome, it will become female; if it receives the Y, it will become male. Thus, the presence of the Y chromosome determines maleness. This is one respect in which the Y chromosome is unique – it is only carried by males.

The Y chromosome is also unique in that it does not undergo recombination like the autosomes. During the formation of the human embryo the autosomes exchange bits of DNA with each other, and therefore their makeup is changed each generation. However, the Y chromosome does not undergo recombination and is therefore passed down virtually unchanged from father to son, then from that son to his sons, and then to their sons, and so on, so that our own Y chromosome will be virtually identical to that of other descendants of our recent ancestors in the direct male line. This is what makes an analysis of the Y chromosome so useful in genealogy.

Mutations
Although the Y chromosome is passed down without recombination from generation to generation, it does not remain entirely unchanged over the generations. During transmission from father to son the Y chromosome sometimes undergoes a mutation on certain portions of its DNA sequence, so that a son’s Y chromosome will be slightly different from his father’s. There are two types of mutation that are of interest in genetic genealogy: SNP mutations and STR mutations.

SNP is an acronym for Single Nucleotide Polymorphism, which is a mutation at a specific place on the Y chromosome of one of the 4 nucleotides mentioned above (adenine, tymine, cytosine and guanine) to its complementary base (i.e., adenine to thymine or cytosine to guanine, or vice versa). SNP mutations occur so rarely that they are basically unique events and all individuals whose Y chromosome contains a particular SNP are considered to be descended from the same individual, the one whose Y chromosome first underwent that mutation. It is these mutations which have allowed population geneticists to define individuals by haplogroup and which have helped them trace the prehistorical migrations of mankind. The presence of these mutations is useful in determining one’s ancient ancestry.

In our project we don’t test SNP mutations as a rule. Instead we are interested in certain pieces of the Y chromosome that contain what geneticists call “junk DNA”. This “junk DNA” doesn’t serve any biological purpose. You may think of it as genetic filler. At certain locations on the Y chromosome a sequence of junk DNA is repeated a certain number of times. These locations are referred to as STRs (Short Tandem Repeats). Occasionally one of these STRs will undergro a mutation so that the number of times the sequence is repeated increases (known as an insertion) or decreases (a deletion) at a particular location. These sorts of mutations are not as rare as SNP mutations, and that is why they can be so useful in genealogy. The degree to which individuals share STR values can indicate the degree to which they are related in a genealogical timeframe. While SNP mutations allows us to trace groups of humans over thousands and even hundreds of thousands of years, STR mutations allow us to trace individuals through the centuries, even to the point of possibly determining whether two individuals might share a common Vance ancestor in the direct male line. Your test results will consist of the values your Y chromosome has at the particular DYS locations which FTDNA tests. There will be from 12 to 37 of these locations, depending on which test you ordered. Your allele values at these DYS locations together represent your haplotype.

Reporting Your Results
You will be notified by FTDNA when your results come back from the lab and then you will be able to view your results on your personal page at FTDNA. We will also post your results on the results page of the project website.

Your personal page at FTDNA consists of 6 subsections, described below roughly in reverse of the order in which they are listed on FTDNA’s site:

Y-DNA DNS values: This section contains the allele values at the various DYS locations that FTDNA tests. The DYS numbers are just names for the various locations of junk DNA that are tested for the number of repeats present at that location. The allele represents the number of repeats you have at that location. Your allele values constitute your haplotype.

Haplogroup: The STR mutations we test for in our project will not prove your haplogroup. Only an SNP mutation will do that conclusively. However, for most people an SNP test is not necessary for determining haplogroup with a reasonable degree of accuracy. In the haplogroup section of your personal page at FTDNA you will find listed people whose haplogroups have been confirmed and who are 4 or less mutations away from your own haplotype. Chances are very good that you will belong to the same haplogroup as the majority of these individuals, although in certain cases it is not as clear. FTDNA also provides a brief description of each haplogroup represented on your Haplogroup page. These descriptions should be taken with a grain of salt. There is still much argument about what the various haplogroups mean or how they should be defined historically and geographically. A more in-depth understanding of haplogroups will require some study, which we will be able to assist you with.

Another tool for predicting one’s haplogroup is the Haplogroup Predictor developed by Whit Athey and found here: https://home.comcast.net/~whitathey/predictorinstr.htm. When we report your results on the website we will include your haplogroup as predicted by FTDNA (if they are able to predict it) and as predicted by Whit Athey’s tool. Again, in certain cases no clear prediction will be possible.

Country of Origin: In this section of your personal page, FTDNA provides the countries of origin of those individuals whose haplotypes match yours closely. This will give you some idea of where in the world your haplotype is frequently found.

Y-DNA Matches: Here you will find names and contact addresses for individuals from FTDNA’s database whose haplotypes are very similar to yours. You will probably be most interested in your matches from the Vance project, but individuals from other projects will also be included in this section should their haplotypes match yours closely. If you happen to match someone with a different surname it doesn’t necessarily mean you are related to that person in a genealogical timeframe. You may match them through a phenomenon that is generally known by the misleading term “convergence.” Convergence refers to the fact that two individuals who descend from the same haplogroup founder through lines that are unrelated in a genealogical timeframe have wound up with haplotypes that are a close match. In some instances a close match with an individual of another surname could indicate a relationship in a genealogical timeframe, but these will need to be looked at on a case-by-case basis. If you happen to have a fairly common haplotype then you will probably see numerous individuals with different surnames listed on your Y-DNA matches page. You may choose whether to view matches only with your own surname or with all those in FTDNA’s database on your Setup Preferences Page.

Genographic Project: In this section FTDNA gives you the option to join the Genographic Project, a collaborative effort of the National Geographic Society, the IBM corporation, geneticist Spencer Wells and the Waitt Family Foundation. FTDNA is the company which tests individuals for the project. They allow their customers to participate in the Genographic Project by transferring results into it for a donation of $15. This donation will be directed to the Legacy Project, which supports local education and cultural preservation efforts on behalf of the indigenous communities who have been tested for the Genographic Project. Should you choose to donate and thereby join the Genographic Project, you will then be able to log on to the National Genographic site and view your results there along with several graphics which depict the movement of your haplogroup in the light of the entire prehistory of mankind.

In addition to FTDNA’s reporting of your results, you will also find your results posted to this website along with the results of all the other participants. In a table on the Test Results page you fill find each individual represented by their unique Kit ID as assigned by FTDNA. We will also provide the individual’s predicted haplogroup (or their actual haplogroup if they have been SNP tested) as well as all their haplotype. Mousing over an individual’s kit number will cause the name of that individual’s earliest known Vance ancestor to appear (Note: some web browsers may not support this feature). Clicking on an individual’s kit number will take you to a display of that person’s lineage from his earliest Vance ancestor down to his great grandfather so that you may compare your lineage with theirs. The results inside the table will be organized first by haplogroup and then by haplotype. Individuals who match closely with each other will be listed next to each other in the table and will be set apart from the other participants by a unique shading.

Interpreting Your Results
When your results come back from the lab, the first thing you’ll want to do is compare them with the results of the other participants. Quite simply, the more mutations that separate your haplotype from another participant’s haplotype, the less likely it is you are related. It’s important to note in this context that even a mismatch has meaning, in that it indicates you are not related to that individual. For instance, if you thought you might be a descendant of John Vaus of Barnbarroch you could compare your results with the results of participant 39200. If your genetic distance was great enough from his it would indicate that you were not descended from John Vaus of Barnbarroch (Note: genetic distance is simply how many mutations separate your DNA results from another’s). However, if your genetic distance is not very great and you share the same surname, then there may be a chance you share a common Vance ancestor. As a general rule, in order to confirm that a particular individual’s haplotype is an accurate reflection of his earliest Vance ancestor, we require the presence of a related haplotype from at least one other individual descended from that ancestor through a collateral line.

How close is close enough to indicate a relationship? Here’s how FTDNA interprets genetic distance on 12 markers.

Distance Relatedness Explanation
0 Related Your perfect 12/12 match means you share a common male ancestor with a person who shares your surname (or variant). These two facts demonstrate your relatedness, however if your name is one of the most common surnames, i.e. Smith, Tailor, Miller, etc, (trades or towns) then we always suggest you utilize our 25 marker test to eliminate the possibilty of a random surname and random genetic match.
1 Possibly Related You share the same surname (or a variant) with another male and you mismatch by only one 'point' on only one marker. For most closely related or same surnamed individuals, the mismatch markers are either DYS 439 or DYS 385 A, 385 B,389-1 and 389-2. To ensure that the match is authentic you should refine to the 25 marker test.
2 Probably Not Related You share the same surname (or a variant) but are off by 2 'points' or 2 locations on just 12 markers. It is only possible that you and another related family members' line each have had a mutation. There are two ways with DNA testing to confirm or deny. One is to test additional family members to search for a line that shows a mutation that is 1 point closer to your sample. The other is to order the Y DNARefine 13-marker panel. Refining greatly enhances sciences ability to determine relatedness -- geared towards the most accurate assessment of the number of generations to a shared ancestor. Only by further testing can you find the person in between each of you...this in 'betweener' becomes essential for you to find, and in their absence we feel you are not related.
3 Not Related 9/12 - is too far off to be considered related. Unlikely but vaguely possible that the rule for Probably Not Related applies.
4 Not Related 8/12 - You are not related and the odds greatly favor that you have not shared a common male ancestor with this person within thousands of years
5 Not Related 7/12 - You are not related and the odds greatly favor that you have not shared a common male ancestor with this person within thousands of years.

FTDNA’s interpretation of genetic distance on 25 markers:

Distance Relatedness Explanation
0 Related Your perfect 25/25 match means you share a common male ancestor with a person who shares your surname (or variant). These two facts demonstrate your relatedness.
1 Related You share the same surname (or a variant) with another male and you mismatch by only one 'point' on only one marker. For most closely related and same surnamed individuals, the mismatch markers are usually either DYS 439 or DYS 385 A, 385 B,389-1 and 389-2 from our first panel of 12 markers, and on the following from the second panel: DYS #'s 458 459 a 459b 449, 464 a-d, which have shown themselves to move most rapidly. The probability of a close relationship is very high.
2 Probably Related You share the same surname (or a variant) with another male and you mismatch by two 'point' on on from the 25 markers we tested. For most closely related and same surnamed individuals, the mismatch markers are usually either DYS 439 or DYS 385 A, 385 B,389-1 and 389-2 from our first panel of 12 markers, and on the following from the second panel: DYS #'s 458 459 a 459b 449, 464 a-d, which have shown themselves to move most rapidly. The probability of a close relationship is good, however your results show mutations, and therefore more time between you and the other same surnamed person.
3 Probably Not Related You share the same surname (or a variant) but are off by 3 'points' or 3 locations on the 25 markers tested. If enough time has passed it is possible that you and another distantly related family members' line each have had a mutation, or perhaps 2. The only way to prove that is to test additional family lines and find where the mutation took place. Expressed another way, assume your score puts you at 3 on the clock. Assume the person 3 from you is at the 9 position. Only by further testing can you find the person in between each of you...this in 'betweener' becomes essential for you to find, and in their absence the possibility of a match exists, but further evidence should be pursued.
4 Not Related 21/25 is too far off to be considered related. Unlikely but vaguely possible that the rule for ONLY Possible related applies. It is important to determine what set of result most typifies 'most' members of the group you are 'close' to matching. You may be 21/25 with an individual, but 23/25 with the center (most common) of the group, and your potential relatedness to him is through the center of the group.
5 Not Related 20/25 You are not related and the odds greatly favor that you have not shared a common male ancestor with this person in excess of 2,000 years
6 Not Related 19/25 You are not related and the odds greatly favor that you have not shared a common male ancestor with this person in excess of 5,000 years
over 6
Not Related You are totally unrelated to this person.

That’s the general idea. However, there is some gray area here. Just because your genetic distance from another person is 2 or even 3 mutations on 12 markers doesn’t mean you aren’t related. It just means that the probability is not as good as if you matched 11/12 or 12/12. We know of numerous examples from other projects of individuals whose genetic distance was 10/12 or even 9/12, but who were revealed to be closely related after an upgrade to 25 markers. For that matter, a genetic distance of 11/12 is not enough to conclusively prove a relationship, since it’s possible that an upgrade to 25 markers will reveal enough mutations to indicate no relationship in a genealogical timeframe. We also know of numerous examples of this phenomenon from other projects.

Most Recent Common Ancestor
A close match of your DNA results will not tell you the name of your MRCA (Most Recent Common Ancestor), but it can give you a rough time frame for when that MRCA probably lived. By analyzing genetic distance in light of mutation rates for the Y chromosomes DYS markers, we can arrive at a rough estimate of the TMRCA (Time to Most Recent Common Ancestor).

There is some dispute over what constitutes a valid mutation rate for the Y chromosome’s STRs. The most agreed upon rate is 0.002, or 0.2 percent chance of a mutation per marker per generation. This translates into roughly one change every 500 generations for each marker. Since we are dealing with more than one marker, the TMRCA estimate involves a statistical calculation of some complexity. Bruce Walsh has developed a tool which provides a TMRCA estimate based on the most commonly accepted mutation rate of 0.002.

The rate of 0.002 is generally valid when looking at all the DYS markers as a group. But as more and more individuals have been tested, it has been increasingly noticed that certain markers mutate at a faster rate than others. (These faster-mutating markers are colored red in the results chart.) FTDNA has developed a tool (FTDNATiP) that takes into account these different observed mutation rates and incorporates those rates into their calculation. If your results match somewhat closely with another participant’s, we will analyze your results using these tools to help determine when your MRCA might have lived.

Most analysis of DNA results will involve viewing the results in conjunction with traditional genealogical evidence, and every case will be different. This is very important to keep in mind - on their own DNA results are not enough to indicate the exact nature of a relationship, but when viewed alongside other individuals’ results and along with traditional genealogical evidence quite often the relationship may be found. You may also find that your DNA results will provide a new focus for your research. DNA can close off old avenues and open up new ones, and can often strengthen or disprove existing lineages.