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New to DNA Testing Questions & Answers
Part I: DNA & Genetics
  1. What is DNA? DNA is Deoxyribonucleic Acid. It is the molecular material making up our chromosomes in the nuclei of our body cells.

  2. What is DNA testing? Scientists examine human DNA for different reasons. Crime labs, for example, may look at DNA at an entirely different way than a medical doctor trying to advise a patient which in turn is different from the way a genealogist might look at data.

    For our purposes, we are looking at DNA only for genetic ancestral research. Surnames and Y-DNA characteristically go together because fathers have historically passed on surnames to their children AND Y chromosomes ONLY to their sons. For the son, the Y chromosome and the surname are a package deal. The Y-DNA test looks only at those locations on the Y chromosome that might help carve out family groupings.

  3. What laboratory is handling the DNA testing for this project? Family Tree DNA (FTDNA), the same company that sponsors the DNA testing aspect of the television program "Who Do You Think You Are?"

  4. How is DNA collected for testing? DNA can be collected from any human tissue. It has even been collected by drilling into the bones and teeth of ancient skeletons! But for our testing, the process is two quick and painless cheek swabs.

  5. Does DNA testing reveal my private medical problems?!? There are DNA tests that do test for the tendency to develop certain conditions or for inherited health conditions. The Y-DNA and autosomal DNA genetic tests do not test for such health conditions, though there may be some correlation between specific haplogroups/subclades and certain health conditions.

  6. How does the Y-DNA test work? The X sex chromosomes in a female and the autosomal chromosomes of either gender recombine to create one chromosome to pass to a child as part of the pair the child receives. The Y chromosome does not generally recombine the way the others do.

    There is DNA in the non-combining part of the Y chromosome that almost never changes so is considered very stable. This DNA is used to identify the branches of the human family tree, going back many tens of thousands of years. In order to confirm your human family tree branch, you would have to get a special test, which is not the main purpose of this DNA project. However, when you do your Y-DNA test for this project, FTDNA will attempt to predict your family tree branch.

    The Y chromosome also has a region considered "junk." On this junk are DNA locations that are interesting to genetics researchers. Two testers who have identical or nearly identical matching junk DNA may share relatively recent common ancestry. These DNA pieces are scientifically studied to determine how often they change (mutate). Some mutate very quickly (every few generations) and some mutate quite slowly (maybe once or twice in a thousand years). Taking into account different mutation rates for different pieces, the testing lab estimates how many generations back you and another tester shared a common ancestor. Your Y-DNA test looks at this DNA in particular.

  7. Is Y-DNA testing the same as paternity testing? NO it is not. However, Y-DNA testing may reveal what is called a non-paternity event (NPE) somewhere in the paternal line. This may be discovered when two brothers or first cousins who are the sons of brothers test and their test results don't match. Adoptions, name changes, illegitimate births with hidden paternity, or infidelity are such events. Everyone has these NPEs at some point in their family history and there is a chance a Y-DNA test could reveal such an episode. This is a risk you should consider before testing.

  8. What is a marker? A marker is a location on the Y chromosome that is genetically interesting. A number of markers along the Y chromosome have been identified as useful for ancestral testing. The more markers tested, the better the information we get from the test.

  9. How many markers can I test? It depends on the laboratory doing the test. At FTDNA, there are tests available for 12, 25, 37, 67, and 111 markers.

    In this project. 37 markers is the minimum needed as anything less is usually inadequate for ancestral research. If you have a lot of matches, the 67 and 111 marker tests will filter your matches and help identify those who most likely share more recent common ancestry with you.

    If you first test for fewer markers, you can upgrade your kit at a later time. Some testers wait for test sales for upgrade opportunities.

  10. Does a perfect 37/37 match prove we are related? Such a match carries a high probability you share a common ancestor within the past millennium. You and your match would both need to test more markers to ensure the match persists to relatively recent times and to better determine how recent your relationship is.

  11. Why should I upgrade my markers if I have no matches at 37 markers? Upgrading to 67 markers or more is important for several reasons.

    In your particular genetic branch there may be more volatility in the markers, say, between 25 and 37, and more stability after 37. FTDNA only displays matches for GD = 4 or less for 37 markers. If you are matching people at GD = 5 for 37 they would not be in your match list. At 67 markers, FTDNA displays matches with GD=7 or less. So for example, say GD=5 in the first 37 and GD=2 in the next 30 for total GD=7 in 67; that person would not appear in a 37 marker match list but would appear in a 67 marker list. Some genetic families are slow mutators and some are volatile in their mutations.

    If finding recent genealogical matches is your goal, you aren't likely to find them at 37 markers unless there is something unusual about your particular family lineage making members recognizable at 37 markers.

    We all have an "expiration" date and have a limited amount of time. Your cheek swab sample will get old. Your entire marker definition should be on the record, so that your relatives and descendants will have that data and can continue your research where you leave it off. There are NO guarantees you will find recent genealogical matches at 67 or 111 markers. The science of genetic genealogy is still new, and few men have done genetic testing compared to the potential pool of testers. In addition, there could be circumstances in your family line, i.e., "daughtering out," that might make it even more difficult to find a close range genetic cousin. In such circumstances you will have to be patient and wait.

  12. If I want to upgrade my markers do I need to submit another cheek swab? No, not usually. Should circumstances arise that the lab needs more of your sample, it sends you another test kit; you will not be charged.

  13. What does Y-DNA data look like in my FTDNA account ? Y-DNA is typically presented in a table showing the names of markers and the values found in your sample.

    This is how Y-DNA data is presented in your FTDNA account.

  14. What will my Y-DNA look like on these project web pages? This is similar to how your Y-DNA data will appear on this website.

  15. What do these numbers mean?!? Each marker that you see in your results can only take a certain range of values. Each possible value for that marker is called an allele. The value is a measure of the behavior of the genetic material at that location, i.e., how many copies of a pattern.

    A DNA laboratory finds your matches by comparing your alleles with others in their database. If two testers share an identical or extremely close allele pattern they may share meaningful recent ancestry.

    The laboratory uses the differences between your alleles and those of another tester who matches you to estimate how many generations back your most recent common ancestor lived. Such an estimate takes into account the known mutation rates of those particular markers that differ.

  16. What do the terms haplotype and haplogroup mean? A haplotype is the scientific term for leaves within the genetic tree of man tree and a haplogroup refers to a branch. A collection of meaningful meaningful STR results with very similar values create a haplotype. A haplogroup

  17. What is a clade and a subclade? A clade is a branch off a branch and a subclade a branch of the clade branch. Both a clade and a subclade are by definition haplogroups, the terms are used for convenience so as to speak of the patriarch as the haplogroup and split descendents by branches. Subclades are confirmed by SNP testing.

    Researchers are ALWAYS looking for correlations between haplotypes and subclades, and sometimes the words are used interchangeably. A STR marker mutation (what characterizes your haplotype) could signal the presence of a particular SNP (your subclade). A haplogroup is a collection of haplotypes sharing some SNP mutation defining a clade or subclade.

  18. What is a STR? An STR is the abbreviation for Short Tandem Repeat marker. Your Y-DNA test is a Y-STR test and is used to characterize your haplotype in the tree of man. The value you see at a particular marker is the number of time a DNA pattern repeats.

  19. What is a SNP? SNP ("snip") is an abbreviation for Single Nucleotide Polymorphism. They are used to characterize your haplogroup (branch) and subclade in the tree of man.

    Normally when your sample is tested, FTDNA makes a prediction about your haplogroup. However you would need a SNP test to actually confirm it. If you have very close matches at 67 and 111 markers and one of your matches has a confirmed haplogroup or subclade, you can probably assume that is also your haplogroup.

    A terminal SNP is the SNP that defines a known end branch in the giant family tree of man, the last branch in a series of branches off the trunk leading to a leaf. Haplogroup project researchers are ALWAYS looking for correlations between the presence of certain SNPs and certain mutations on STRs.

  20. My second cousin and both have the same surname and have the same great grandfather yet we are in different haplogroups. I refuse to believe a non-paternal event ocurred. Isn't it possible to be related yet in different haplogroups? Yes. For different parent haplogroups, e.g. I vs R, it is improbable they are related. For different subgroups deep in a parent haplogroups descendants tree it is possible, e.g. R-A224 a branch of R-A223 deep in R. The yDNA matches can only say what is probable and you will have to decide from that was is possible. It is not unlike the decisions jurors have to make when contemplating reasonable doubt. Some numbers to consider:

    Genetic Distance For 67 Markers Probability of a common ancestor within 3 generations
    13 2 in a billion
    10 0.00003%
    5 0.3%
    1 40%

    The probabilty is never zero. Hence no matter the genetic distance (GD) between two people in different haplogroups it is theoretically possible they are related. At GD=1 it is clearly possible, at GD=5 it rarely happens and at GD=10 it probably never happens for practical purposes. So where do you want to draw the line?

  21. What does TMRCA mean? This is the time or number of generations back to the most common recent ancestor (Time to Most Recent Common Ancestor) shared by two or more people.

  22. How long is a generation in years? The project assumes an average of 33.5 years per generation in any computations of TMRCA.

  23. Is there a relationship or correlation between STR markers and deep SNPs? The relationship between STR and SNP mutations is very difficult to explain. They occur independently of one another yet many Haplogroups can be predicted from STR. Likewise there are plenty of Haplopgroups that cannot be predicted from STR, especially in R. With that as a preface you would need to discuss diffusion and extinction as processes.

    Here is a silly analogy. Consider a pond and somebody pours a gallon of ink in the center. That ink in time spreads out by diffusion, the center is the modal and radius from center is genetic distance. STR mutations can be represented by ink concentration and further off center the lower is the concentration. Until some other process kicks in everybody at a given radius has the same STR.

    Now imagine a bird flies over and lets loose with poop that all lands in one spot at random in the ever growing ink circle. The poop represents a one time event such as a SNP mutation and it is measured not by concentration but is it in a water sample or not. Right after the poop first drops, other water samples equidistant from the center have the same concentration of ink but no poop. So in this case you cannot predict the existence of poop by measuring ink concentration, analogous to to being unable to predict a haplogroup from STR. As time continues the water soluble poop also spreads by diffusion.

    Now some time later the fickle finger of fate enters the picture in the form of extinction. A man with a special vacuum cleaner sucks out the infected water nearly everywhere but carelessly leaves behind two blobs; one poop infected sampled from one radius and another not infected from a significantly different radius. Finally along comes a kid with his science kit and he discovers that poop free water has 100 times less ink it than contaminated water. Hence he has found a way to predict that water is contaminated without having to measure the poop (SNP); one simply has to measure the ink (STR). The kid wins a blue ribbon at his school's science fair.

    Haplogroups that are young can't be predicted from off modal STR, the SNP has to be tested, like right after the bird pooped you can't predict the existence of poop from the ink, you have have a poop test as well. In the old haplogroups there has been enough time for extinction to kick in and now the SNP of subgroups can be predicted from the STR.

  24. Can I test my deep SNPs? Yes. FTDNA has a test called Big Y that tests several thousand SNPs. However, there are also options to test smaller SNP clusters and individual SNPs. For this project, members for the most part are expected to be in the R1b haplogroup. The M343 panel is an alternative to Big Y, if you don't want to spend the funds on Big Y but still want to confirm your subclade.
  25. I am new to genetic genealogy. Where can I learn more? ISOGG has some newbie resources; see Also consider joining the newbie forum on Yahoo; ISOGG also maintains an excellent Genetics Glossary. Family Tree DNA has a learning center.

Part II: Doing a DNA test for the Project
  1. Where can I purchase a test? Right here!

  2. Why was FTDNA the lab chosen for this DNA Project? FTDNA, founded in 1999, has been doing genetic testing longer than any other commercial genetic testing lab. It has the largest database of testers from around the world and surname research projects administered by volunteers who receive no compensation. It actively encourages and supports research projects and their administrators and provides the tools to do. In addition, there are no subscription fees to see your matches.

  3. How is my DNA collected? FTDNA sends you a cheek swab kit. You take two cheek swabs and enclose them in the return envelope.

  4. Is my privacy compromised? No. In your FTDNA account, you can modify your profile and privacy settings. Your name and email address are revealed only to persons in deemed by FTDNA to match you close enough to warrant contacting each other about your respective genealogies. You may wish to review the vendor's policy statement. In this DNA project, in this project you are identified by a kit number and your earliest known ancestor. The type of DNA testing will not uniquely identify you as an individual.

    It is a project requirement for you to share your genealogical data with others. Data published on this website will use ONLY your surname but otherwise omits personal information, and uses your kit number. When the project administrators create your test kit page, you can work with them to specify exactly who you want on the page to remain private.

    See "What are project members expected to do?" on our FTDNA FAQ for how to set up your account.

  5. Are there risks associated with DNA testing for genealogy? Yes, the risks are similar to what you might learn via conventional genealogy, e.g. you might uncover an adoption or other non paternal event which could cause emotional distress.

  6. How do I release my data for research? FTNDA sends you a consent form with the kit which you sign and send back with the kit. By signing this form you say that you are allowing yourself to be tested. Then, by monitoring the privacy settings in your profile, you can choose to let project administrators see your data in any projects you join. In that way you release your data for research. Your project administrator will know who you are, but that information is kept confidential. In this DNA Project, we ask that you share information about your earliest known project-related ancestor, and provide a minimal family tree to be shared with others. You decide how far to extend this family tree. It should not include you or any living parents or grandparents.

  7. How do I send back the kit? If you are mailing from outside the United States, it is strongly recommended that you purchase a delivery confirmation or tracer from your local postal service to prevent the package from getting lost. Otherwise, drop it in the mail.

  8. How long does it take to get results? Expect four months.

  9. My 4th great-grandfather is Denis Hourihane born 1745 in Ireland. As I am female, could one of my sons do the DNA test? No, the surname testing is based on the "Y" chromosome which is a paternal test and thus all samples must be derived from a male with a project surname or a variant thereof.

  10. There are no living males of my line. However, I do still have some of my Dad's hair, could that be tested? Here is a quote from Roberta Estes on the subject: "The hair needs to have a follicle, so cut hair doesn’t work. However, even hair with a follicle, the success rate is significantly less than 50%, and it costs upwards of $1000 per attempt. Hold on to that hair, without touching it, for new technology."

  11. Is there any advantage in having a father and a son both test yDNA? Ususally not. However, quirky mutations have been known to occur between father and son.

    Testing both is warranted if there is something unusual or one has concerns about quality control. Even so, if you are matching a lot of people who share your surname the one test should be adequate. If however, you don't seem to be matching anybody by your name it would be useful to test as distant a cousin as you can find since a close enough match would rule out any non-paternal events from at least the most recent common ancestor on down.

  12. What if I have already tested at another company? If you wish to join this DNA Project, you may purchase an upgrade if your testing company used Sorenson's lab. Choose the Transfer Y-DNA46 with Y-DNA37 upgrade product. DO NOT CHOOSE THE $19 TRANSFER products as they will not give you matches or a haplogroup prediction!! !!

  13. How much do these DNA tests cost?

    Check FTDNA for current prices. If you order through our coded project link , there is a slight discount.

    FTDNA normally offers sales in the summer and at the end of the year.

Last updated: Tuesday, 06-Oct-2015 09:24:25 MDT


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