How is DNA used in genealogy?
We compare the DNA of two people to see if their samples match and, if they do, those two people may be related. If their DNA does not match, we know they are not related. All of your DNA came to you from your parents – half from your mother and half from your father. Most of it is a random "jumble" of fragments from your mother and father, which makes it difficult to tell which ancestor contributed which part. This jumbled DNA is called "autosomal" DNA. There are two components of your DNA which are not jumbled up when passed to the child. Each of them comes from only one parent, the mother or the father, and they are virtually identical to everyone in that maternal or paternal lineage for hundreds or thousands of generations back in time. The type that comes from the mother is mitochondrial DNA (abbreviated mtDNA). The type that comes from the father to his sons is Y-chromosome DNA (abbreviated Y-DNA). Genealogists are now using all forms of DNA to do research into ancestry, but the Y-DNA and mtDNA, in that order, are still the most useful.
How do we find the DNA signature of ancestors who lived long ago?
We like to use a process called “triangulation“. In this process, DNA test results from several lines of living descendants (or people who believe they are descendants) of a common ancestor are compared to each other. An analysis of the results can paint a picture of the ancestor’s DNA signature. The most effective and accurate method involves determining signatures of recent ancestors first and then comparing their results to determine the signature of more distant ancestors as we work our way back in time. The accuracy of the results depends on the number of test results available, the distance (in relationship) of the test subjects and the availability of paper trail information (pedigrees) to help in the analysis. We also use the “modal value“, but it can be less accurate if the test results are not evenly obtained from the set of cousins.
Will a DNA test tell me who my ancestors are?
No, but your DNA provides clues to help identify them. A Y-DNA or mtDNA test will provide you with a "signature" identifying either your direct paternal or maternal line, respectively. Other forms of DNA data can also help determine if you might be related to someone else. That evidence is combined with traditional forms of evidence to prove the relationship to the other person or persons. Once you identify a relative, your shared knowledge, along with traditional research methods, provides you with more clues to your ancestors. The DNA data – if there are enough people in your group – can indicate when your lines intersect, which narrows the search for the common ancestor. As more people contribute their test results to the study, it is possible to focus the search for a common ancestor to a specific lineage and within a few generations.
I tested and match another person. Neither of us know anything about our ancestry. How has the DNA test done anything to help us?
You now know more than you did – you have found a researcher to whom you are related. Now it’s time to combine your knowledge of your ancestry and to apply traditional research techniques, e.g. examining where and when your ancestors lived, who they associated with, what they named their children (given names can provide family clues as they are often repeated over generations), etc. and then begin working the courthouses, newspapers, libraries, etc.
Why should I get tested?
You might consider participating in the DNA Project for several reasons:
- You want to resolve the mystery of an unknown ancestor.
- You are the last male in your line and want to preserve the DNA for future generations to help with their research.
- Other researchers need a sample from your family branch to help them in their research.
Can the test results be used to tell me of potential medical problems?
No, the type of testing done for this test has no medical value.
Can these results be used to compromise my identity?
The Y-DNA data used in our project provides a signature for all males descended from your ancient ancestor. It identifies a large group of related people. The data, by itself, cannot be used to identify any specific person. It must be combined with other information to do that. Your test results are either identical to or very nearly identical to those of all your male relatives who are descended from your distant paternal grandfather. This includes your father and uncles, your distant cousins, your grandfather and granduncles, etc. The answer to the question is "it depends on how much other information is available".
Will my test results be used for any other purpose?
No. The privacy of your identity and that of your test results are guaranteed by numerous safeguards. See the company’s Privacy and Confidentiality statement.
I'm told I have a match with someone else – what does that mean?
That depends on how much data you have (i.e. how many markers are being compared and the number that match). The accuracy of an estimate of relationship increases as the number of markers compared increases. A match of 100% at 12 markers could mean the people are siblings or it could mean they share a common ancestor from hundreds of generations ago. A perfect match at 67 markers is a good indication there is a shared common ancestor within only a few generations. DNA is a tool that complements traditional research.
How many markers should I test?
The current number of markers tested are 12, 25, 37, 67 and 111. – The 37 or 67-marker test has proven to be the most useful for our family Project. – A 12-marker test is best suited to tell you whether you are NOT related to another family. If you don’t match at 12 markers, you can be assured there is no recent common ancestor. On the other hand, it is common for people to match at all 12 markers and not be recently related. This is because we are all so closely related. More markers will give a better idea of whether a recent relationship exists (within a reasonable genealogical time frame of 1,000 years or less). – The 25 marker test can be a good indicator whether a recent relationship exists. – The 67 marker test, at least for our group, appears to be most useful for sorting out very recent relationships.
I'm told my sample is too far apart from another person for us to be related. Is this true?
Probably, but there is the remote possiblity your family group’s DNA signature "drifted" faster than the average mutation rate, making the computation of your group’s genetic distance inaccurate. You will need to collect DNA signatures from other parts of your family branch to confirm the high mutation rate or you will need solid evidence from traditional sources. Don’t give up, but it’s likely you’re not related within a useful time frame.
If Y-DNA only traces the paternal line, and mtDNA only traces the maternal line, how do I find out about my ancestors in the other lines?
Search your other family lines in the same way we’re researching this one – find a male from that line and have him tested. Autosomal testing can help with recent ancestry (within approximately the last four or five generations.)
I am a woman, can I participate in the Project?
We really want your contribution and help with the Project. The Project uses Y-DNA and only men have that, but you can contribute to the effort by helping us recruit men into it, e.g. getting your father or an uncle or your brother or cousin to submit a test sample.
I know I was adopted. Is there any benefit in my joining the Project?
You would do this if you wanted to locate the line from which you are genetically descended. If you know the surname of your biological father, then you’d be best served by joining the Project for that surname. If you don’t know, you’re welcome to join the Cloud DNA Project. Once your results are in, they can be uploaded to the Y-Search worldwide database. You’ll find information there on others who share similar signatures as you.
How do I get my relatives to join the Project?
You can tell them this is important to you. Offer to pay for the test for them. Tell them their data will help all of us learn more about our ancestry (it will take many tests from our distant branches to be able to peer back into the distant past). Share with them your copy of the Cloud Family Association Journal and tell them we are earnestly working to learn about and preserve our heritage, and DNA testing can help with that.
I'm told I don't match other members of the Project. Does this mean I'm not a Cloud?
A surname is an artificial and arbitrary designation. Your surname is simply an identifier for the family group you identify with. No one even had a surname in the middle ages and before. Someone, somewhere settled on usng this surname – what does it matter whether it was adopted 500 years ago or 50 years ago – it’s still your surname and it is valid. We suspect there are many unrelated families with the surname Cloud. There are records of Clouds coming from many countries of origin. William Cloud left England in 1682 to travel to America, and early census records, ship manifests and even the Ellis Island records show Clouds who immigrated from other countries besides England. There are also Native American people who took the surname Cloud. These are all distinct family groups that aren’t related to each other – but they all are Clouds.
How do I join the Project?
You will purchase a test for 25, 37, 67 or 111 markers from our testing company. You will need to submit whatever information you know about your pedigree to the Project Administrator. When you receive the test kit in the mail, you’ll use the two swabs to collect samples from the inside of your cheek. Then you’ll return the samples to the testing company. Both you and the project administrator will receive your results.
How will my DNA information be used?
Your DNA test results will be compared with the results of other participants to see if there is a possible match. If there is, your pedigree information will be compared to theirs to find any common factors. That will give you and other researchers clues on where to look to resolve the broken links. Your data will also help us establish a better idea of the DNA signature of our distant paternal ancestor, and we need as much data as we can collect to accomplish that.
Why do you need my pedigree information? Isn't that what the DNA test is for?
We learn more about our connections by comparing both our DNA test results and our pedigree information. The results from a DNA test will place you in a large pool of relatives. You reduce the size of that pool by comparing the markers which differ, but there is no way to know, from the DNA alone, how you are related to those people. A pedigree, even if it is inaccurate, is the next step in putting the pieces together. We use the pedigree information to look for clues to how we’re related – dates, places, given names, surnames of collateral lines, etc. DNA doesn’t solve the puzzle by itself, it just adds a useful piece to it.
What is the difference in Y-DNA and mtDNA?
Both forms of DNA can be compared to a family crest – in that they are unique to that line. The mtDNA identifies the maternal line and the Y-DNA identifies the paternal line. Mitochondrial DNA is passed by a mother to her children. This makes it useful for tracing the maternal line – a person’s mother, her mother’s mother, her mother’s mother’s mother, and so on. Every person descended from the same ancient female ancestor will carry virtually identical mtDNA. The Y chromosome provides the same benefit. It is carried only by a man and the son receives a virtually identical copy from his father. Every man descended from the same male ancestor will have very similar Y-DNA though it changes more often than does the mtDNA.
Why does this Project only use Y-DNA and not mtDNA?
The core of the Project is based on Y-DNA because it provides a signature for the paternal line, which is our CLOUD ancestry. Other forms of DNA can also provide useful information to the Project, but they will not be specific to the CLOUD surname and, with the exception of mtDNA, they contain information from all of a person’s ancestors, which makes them difficult to use in a surname project.
Does the project use all forms of DNA (mtDNA, Y-DNA, X-DNA and autosomal)?
The project welcomes input from anyone who has taken a DNA test of any kind, but only the Y-chromosome test can be used in our surname project analysis. That is because the analysis examines Y-DNA markers and the other tests do not return those values. The autosomal and X-chromosome tests return results from all of a person’s ancestors, which introduces so many variables as to make them most useful to closely related people and less useful for distant relatives (e.g. the Project administrator). The Y-DNA test can help trace a surname (paternal) line no matter how distantly related the test subjects may be. (The mtDNA test similarly gives information only on one’s maternal lineage.)
Does it matter what company performs the test?
Why would it matter? Don’t they all do the same thing? No. Not all the companies focus on genealogy. Not all companies have good equipment or practice good quality control (i.e. the results they report aren’t consistently accurate). Not all companies test the same markers we use and some don’t adhere to accepted standards of reporting those markers. Not all companies have good customer service. At least one well-known genealogy company refuses to give the DNA results to their customers, which means they can’t compare their results with people who tested elsewhere.
- Cloud DNA Home.
- Why DNA - Ways in which DNA can help genealogical research.
- Goals - The reasons we're using this tool and what we expect from it.
- Guidelines - The procedures used and how to participate.
- FAQ - Answers to the most common questions about the use of DNA in genealogy.
- DNA Basics - A brief introduction to DNA and how it is used in genealogy.
- The DNA Lab - Information about the testing service that performs our DNA tests.
- The DNA Test - How the DNA sample is taken and what is done with it.
- We need You - Why we need you to join the Project.
- Project Rules - The simple requirements for successful participation.
- Registration - The Registration Form.
- Submit Pedigree - Submit your Pedigree Information.
- What to expect from your Y-DNA test:
- Cloud DNA Project Results:
- Interesting and informative web sites.
- FTDNA Site Map - A useful guide to our testing company's web site.
- Contact – Email the Project Administrator with your questions.
- Cloud DNA forum – Join the Cloud DNA email list.
- * Anyone descended from a Cloud family can join the Project.
- Participation is not restricted to Cloud Family Association members.
- * The Y-STR CLOUD Surname Project can only use data from men who are a descendant through the male-only line of a CLOUD male ancestor.
- Your pedigree is required to facilitate comparison and analysis of your data.
- See "Project Rules" for eligibility.