cs2014c

DNA FAQ

Below is a list of commonly asked questions which were borrowed (with permission) from the Jordan family DNA website. I want to thank them for their willingess to help the Caperton Family DNA Projectd get started with considerable amounts of advise!

Q1. What is this DNA test all about?

Answer: There are two types of DNA tests now available for genealogical testing: the Y-Chromosome (Y-DNA) test and the mitochondrial (mtDNA) test. A direct female line can be traced by testing mitochondrial DNAnswer: However, since we are presently interested in tracing surnames, which are usually passed from father to son, the testing of the Y-chromosome DNA is what we are interested in. The portion of the Y-Chromosome that is tested for genealogical purposes is passed through the direct male line (from father to son) unchanged (other than having an occasional mutation). Human sperm and egg cells contain 23 chromosomes. The 23rd chromosome is the one that determines the sex of the child. Males have both an X and a Y 23rd chromosome, but females have two X's and no Y's. The human egg becomes a female embryo if the male sperm carries an X-chromosome and a male embryo when the sperm has a Y-chromosome. Fathers pass their Y-Chromosomes, or "DNA fingerprints, down to their sons with little, if any, variation, from generation to generation. Therefore, men with identical, or near identical DNA fingerprints (some minor variation can occur), can be genetically proven to be descendants of a common male ancestor. For example, if we have a sample of 30 participants with the surname CAPERTON, the results will reveal who of this sample group are descended from a common male ancestor. Ideally, we would have two or more male CAPERTONs in the same family line participating in order to establish the "DNA fingerprint" for that particular family line. As these matches are established, future CAPERTON participants would be able to readily identify whether or not they match this family DNA fingerprint.

Q2. Will a DNA test tell me who my ancestors are? What will the test tell me?

Answer: No, a DNA test will NOT tell you who your ancestors are. The test WILL tell if two or more participants share a common ancestor, and give you a probability of the number of generations to the Most Recent Common Ancestor (MRCA). Click here for more MRCA information..

Q3. Why do we analyze the Y-Chromosome?

Answer: The Y-Chromosome is the only chromosome passed unchanged from father to son, and therefore indicates the paternal line of descent. All males in a patriarchal line have the same Y-Chromosome. The Y- Chromosome is not present in females.

Q4. What is analyzed?

Answer: We look at specific parts of the Y-Chromosome to obtain a signature. Two or more males whose Y chromosome signatures match come from the same paternal line of descent. Those whose signatures do not match are from different lines.

Q5. Exactly what does a Y-Chromosome match demonstrate?

Answer: A Y-Chromosome match shows that two males have a common male ancestor. This ancestor could be their father, or it could be a male from a thousand years ago.

Q6. Does a Y-Chromosome match prove a relationship between two people?

Answer: Although no evidence is ever absolutely certain, the confidence level for such a match is very high. Typically, there is less than one chance in a 1,000 that the demonstrated relationship is in error if 12 of 12 markers (DYS loci) match.

Q7. What is the advantage of the 25 marker test over the 12 marker test?

Answer: More markers reduce the number of generations to the Most Recent Common Ancestor (MRCA). If you match someone on 12 out of 12 markers, you probably share a common ancestor. If two people match on 25 of 25 markers, the odds are about 1,000,000 to 1 that the two people are related. The question becomes "how far back do you have to go before you find that common ancestor?" If all 12 markers match there is a 50% probability that the MRCA is 14.4 generations or less, a 90% probability that the MRCA is 48 generations or less, and a 95% probability that the MRCA is 62 generations or less. For 12 identical markers, 95% of the possible MRCA values fall between 1 and 77 generations. If all 25 markers match, there is a 50% probability that the MRCA is 7 generations or less, a 90% probability that the MRCA is 20 generations or less, and a 95% probability that the MRCA is 30 generations or less. For 25 identical markers, 95% of the possible MRCA values fall between 1 and 44 generations. Click here for more MRCA information.

Q8. Do Y-Chromosome analyses sometimes match, but not at every point?

Answer: Yes. Over a period of many years, a small number of mutations can be counted on to appear, so there may be one or more points where the Y-Chromosome analysis does not match exactly.

Q9. If no Y-Chromosome match is found, what does that show?

Answer: It demonstrates to a very high degree of probability that the two males analyzed do not share a male ancestor. Although this is true for the two individuals tested, it may not be true for the family groups of the individuals who were tested, because there are a number of sources of non-paternal events.

Q10. My maiden name is CAPERTON and I would love to have this information, but I am female and have no brothers and my father has passed on. There are no living males with surname CAPERTON in my family, only male cousins named CAPERTON, some quite distantly related.

Answer: Your male cousins probably have the same Y-DNA as your father and his male ancestors with surname CAPERTON. Testing your cousins is the same as testing your late father if they are the natural children of your CAPERTON ancestors. That is because the Y chromosome passes unchanged from father to son apart from random mutations. So if your father and your cousins have any known common ancestor, even back to your 4th great grandfather or beyond, the DNA sample should be the same as testing your father, give or take a mutation or two.

Q11. My line split off from the CAPERTON family two hundred years ago. My ggg-grandmother was a CAPERTON. I do research on my CAPERTON ancestors but have no close CAPERTON  relatives.

Answer: If you know or can find male surname descendents of your gggg grandfather CAPERTON, you can in effect test him by testing his descendents. That is because the Y-DNA is passed on without change from father to son. If you test a couple of your CAPERTON cousins and they match, you can say with high confidence that their Y-DNA is very close to the Y-DNA of your gggg grandfather. Then you can compare his sample to other samples in the study and possibly learn much new information about his line for your research.

Q12. Why are you excluding women? We are the children of our CAPERTON ancestors as much as the men.

Answer: We cannot test females for the Y-Chromosome because they do not have one, only males. The technology does not exist to trace CAPERTON surname ancestors through their female descendents, at least not yet. The reason requires going into a bit too much explanation of basic genetics, but essentially we get a blend of genes from our fathers and mothers for everything except the Y-Chromosome, which passes mostly unchanged from father to son. Most other genes combine, thus making every individual unique with a unique genetic s ignature. But that does not mean that daughters are not just as related to their fathers as sons. In fact everyone has genes from all their ancestors, half from each parent, a quarter from each grandparent, an eighth from each great grandparent and so forth back forever. Every gene in our DNA existed in some ancestor 10,000 years ago apart from a few mutations possibly. By using Y-DNA analysis women can learn much valuable information about their CAPERTON ancestors, the same as male descendents. There are tests of mtDNA that trace female lineages, but they are not useful for single surname studies.

Q13. There is only one living male person surname CAPERTON in my family. Is there any point joining the study if I don't have two or three family members who are CAPERTON surname males?

Answer: Yes, there is potentially value for you to join the study. The reason for testing two or three distantly related cousins is that this "validates" the family at least back to the known common ancestor. A single test could provide incorrect data for the family if there is an unknown adoption or a false paternity somewhere back in the past. If you alone take the test and it matches others in the study, you will have learned that your branch of the CAPERTON family is related to theirs, with little doubt. If it does not match and you cannot find any cousin to test to validate the result, at least your sample will sit there in the database until sometime in the future a match is secured.

Q14. I was adopted by CAPERTONs as a child. Is there any benefit to do a DNA test?

Answer: That depends on whether you are trying to trace your "biological" family or your CAPERTON family. If you're trying to trace your "biological" family you would have your own DNA sample tested. If you already know the surname of your "biological" family, it would probably be best to try to find a DNA project for that name since your results would more likely match someone in that group than the CAPERTON group. If you're interested in tracing your CAPERTON family roots you would need a DNA sample from your CAPERTON father or other male CAPERTON family member.

Q15. My male CAPERTON cousins don't care a thing about family history. They won't pay for this.

Answer: There is no rule that says the person ordering and paying for the test must be the person being tested. If your cousins will consent to doing this simple, painless test, you can order the kits on line and then send them to your cousins, and return them with your own payment. Some of the other family reconstruction projects have multiple researchers in the same family line that have split the cost of testing male cousins who have no interest in our hobby.

Q16. I already know my CAPERTON family comes from somewhere in Ireland. What are we going to learn from doing the DNA test that is new?

Answer: You may discover many CAPERTON families that are your cousins that you did not know about before. They may have new information and family histories that will be useful to you, and you will know they are your relatives with little or no doubt. A couple of families named CAPERTON side by side in the census could be brothers, or could be coincidence. But DNA is proof.

Q17. All it takes is one break a long time ago and you won't be able to match up a whole line of CAPERTONs. You will never be able to put all the CAPERTONs together.

Answer: That is very likely true, but the purpose of this is to help different CAPERTON families link up to further their genealogical research. Even if long ago a Mr. CAPERTON adopted a boy whose natural father was Mr. JONES, all his male descendents will still be with a common ancestor, which may prove useful. Also, if someday a JONES has a test done, we may find that match as well!

Q18. How is the DNA sample obtained?

Answer: DNA can be obtained from any cell, but one of the easiest samples is obtained by swabbing the inside of the cheek with a sterile cotton swab. Top

Q19. How do I participate?

Answer: Details on how to participate are provided on this website. Basically each participant only needs to send his full name, address, phone #, and email address to the Project Adminstrator who will order your DNA kit for you. The participant will take his own DNA and return it to Family Tree DNA (FTDNA) in Houston, Texas, along with a check payable to FTDNA. FTDNA will forward your DNA to the Testing Lab at the University of Arizona. Results will be returned to FTDNA who will forward them on to the participant. Top

Q20. How will my DNA information be used?

Answer: This poses a declicate balance between making the information available to others while protecting the privacy of the participants. DNA test results are of little use on there own. Their value is how they compare to other test results and who they match.

Q21. How will my DNA information be protected?

Answer: Only the participant providing a DNA sample and the Project Administrator will know what his results are (unless they decide they would like to share that information - see next question). All samples and identifying information will be received by the Project Administrator and will be assigned an identifying number. This ID number will be the only identifying information anyone else sees, so no one other than the Administrator will know who participates in the study or which result is from which person. The portion of the DNA tested gives a distinctive "signature" for a lineage rather than for an individual, so there is no risk of this data being of any use to anyone for personal identity.

Q22. I noticed my DNA markers match those of several other participants. Is there anyway I can contact them?

Answer: A participant's identity WILL NOT be revealed to anyone unless the participant gave his WRITTEN permission to do so. Since the purpose of this CAPERTON DNA Project is to further genealogical research, participants are encouraged to identify themselves, particularly if they are part of a group, to facilitate open exchange of information. ONLY the PARTICIPANT can make the decision about revealing his identity. If the participant chooses not to identify himself, you can contact the Project Administrator who will forward your request on to the participant.

Q23. Couldn't it be embarrassing if an individual's Y-Chromosome does not match when it should?

Answer: Yes, and for this reason no participant's results will ever be revealed except by a code. Names of participants will not be published or released unless the participant gave his WRITTEN permission to do so.

Q24. My test results do not match any others, does that mean I'm not a CAPERTON?

Answer: There is always a possibility that you could get disappointing test results. Samples that vary by three or more markers from the main group may do so for a number of reasons. One possibility is that they represent distinct lines either older or younger than the currently observed most frequent line. Another is that there has been a non-paternal event at an unknown past time. There are several possible types of non-paternal event in addition to a pregnancy gained outside of a marriage. For example, a child may be adopted and given the JORDAN name; a man may take the CAPERTON name when he marries a CAPERTON daughter; a CAPERTON man may marry a pregnant woman whose husband has died; a couple where the wife is the CAPERTON may choose to give their children the CAPERTON name for various reasons; clerical error in recording administrative data may assign a CAPERTON name to the wrong person, and so on. It should be stressed that adoptions were quite common in every age (ie. parents died by disease or war and a relative took in the children and raised them with their name; or young daughters had a child out of wedlock and the parents raised it as their own). Some may not want to see a result indicating a non paternity event but we are all legal CAPERTONs and a small sample size could be misleading. One may get a DNA sequence which suggests a non paternity event but they could be of the original blood CAPERTON line. Let me explain. Twenty people are tested and 19 are very similar but the last is clearly different. It could turn out that the 19 descend from the same person 300 years ago and this person was an adopted CAPERTON while the other is of the original blood line going back 800 years.

End FAQ