Understanding DNA

Q&As about Premium Male, Premium Female and Premium Combo DNA Reports

What sex-related tests can I take? You can order one or both of two tests. One, the male DNA test, finds markers on the Y chromosome you received from your father (and he from his father, all the way back). There are 43 of these markers in our version of the test. The other is a test of your mother’s female line. This determines markers (“mutations”) on the mitochondrial DNA which you received from your mother. In this way, you find out your paternal (father’s) and maternal (mother’s) gene type.

Why test the male or female lines? Although these are but two out of many lines you have in your family tree, they are the most important. From your father you receive your surname and general standing (class) in society, any hereditary titles and inheritance in the form of wealth and property at least in most parts of the world. From your mother, you get values of morality, religion, education and emotions. Furthermore, these are the only lines that can be tested by today’s laboratories. Any line that crosses from a male to a female or from a female to a male cannot be detected by the current state of genetics.

What is a Y chromosome? The Y chromosome is one of the sex chromosomes, or strands of DNA, we inherit from our parents. Only males receive it. Its only purpose is to make the fertilized egg male and the child that grows up a boy. Otherwise, the Y chromosome seems to have little purpose. It does not make us dark-haired, blue-eyed and so forth. But because the Y chromosome is handed down exactly as it was formed hundreds of years ago, someone who has the same markers comes from the same great-great-great (repeat 10 or so times) father as you. A 24/24 match is probably at least a tenth cousin and could even be closer. You both have the same distant ancestor, for this ancestor passed the same Y chromosome to his sons, and they to their sons, and so forth, down to you and your match.

What is mitochondrial DNA? Mitochondrial DNA (abbreviated mtDNA) is the equivalent of the Y chromosome for the female line. It does for the female line what the Y chromosome does for the male. We get it from our mother, who received it from her mother, on and on, all the way back to Eve, as it were. Like the Y chromosome it changes (mutates) very little from one generation to the next. In fact, it is more stable than the Y chromosome. Consequently, matches have a deeper time depth. If you match the mitochondrial DNA of another individual, you both are descended from the same female ancestor with the past several thousand years. In other words, you carry the same mitochondrial DNA going back ultimately to a common ancient female founder of that lineage. One difference between mitochondrial DNA and the Y chromosome is that mitochondrial markers are mutations and Y chromosome markers are STRs. Both mutations and STrs point to different varieties of DNA.

How do mutations occur? Are they harmful? Mutations are changes in the copies of DNA passed from a parent to offspring. They creep into the DNA record in a random way according to their “molecular clock.” In other words, they are not caused by anything. Sometimes the DNA just changes, and this affects a certain position on the long strands of it that are in every cell of your body. In almost all cases, these changes do not do anything. Only in the case of genetic disease do the mutations have any effect on us. Even though they do not do anything, though, they continue to be passed down in exact copies from parent to offspring. So they are useful in identifying individuals who come from the same ancestor. All these descendants are in the same lineage. Once a mutation occurs it identifies that line forever. Descendants are said to be “downstream” from that change.

What are alleles? Alleles are different variations of DNA at different positions on the long strands. The positions on the Y chromosome are called DYSs or loci (plural of locus). And the positions on the mitochondrial DNA are called nucleotide sites in the control region, the control region being just a small part of the entire strand of mitochondrial DNA. A good comparison is marks we receive in school. In one grade, we may get an A in math and science, a B in English and a C in American history and P.E., while another individual may get As in P.E., English, American history, and Cs in math and science. So you have two very different individuals. We could call the first one a math type, and the second a verbal type. In the same way, one man may be an R1b and another, an R1a, with different aptitudes, ambitions and backgrounds. One individual may be a T2 and another an H, depending on what type of inheritance they received from their mother. One may be African, another Asian. One may be Protestant, another Catholic. It all depends on our scores. This is not to say that the African is better than the Asian, or the Protestant better than the Catholic, however, just that they are different. They have different alleles.In sum, alleles are units of genetic variation.

What is a database, and why are they important? Databases are enormous collections of people’s DNA results. These databases were created by law enforcement officials, commercial companies and professors at universities. They can be searched once you know your own scores to see if others have the same scores as you. (Remember: unlike grades, scores do not make one person superior to another, just different.) The main database for your male line is the YHRD in Berlin, and the main database for your female line is the FBI database. These have the highest number of scores, so it is most likely you will find someone with your own type of DNA in them. Computer programs are used to find your matches. Some databases are anonymous, some have people’s names.

I have a match in the YHRD what does this mean? This means you and the other male (they are all males in this database) have a male ancestor in common. How long ago? That depends. We cannot be sure, but generally it is between a thousand and two thousand years ago. If you both have not only the same gene type but also same last name, it is more recent. You are cousins descended from the same great-great-great (repeat the greats) grandfather. Information of this type is genealogically meaningful. Matches can tell you what your father’s migration history was, what country your male line came from, and help you prove a relationship between you and other males who happen to have your surname. Such genealogical findings are of great importance to people who were adopted and don’t know their father’s name or origin.

I have a match in the FBI database — so? This means you have an anonymous genetic relative through the female line who has been DNA fingerprinted in a study somewhere. The relative’s scores are the same as yours. It does not mean they were a criminal, though. Most of the scores in the FBI database come from university studies where people have volunteered to be tested. Matches can either be close or exact. This depends on how many markers are shared between you. In either case, the connection goes back much farther than a male connection. The female ancestor you have in common lived thousands of years ago, long, long before surnames came into being. Female-linked matches are not genealogically meaningful, usually, but they can tell you a lot about the deep history of all the mothers and grandmothers in the human past.

Who are the Daughters of Eve? As the name suggests, these were branches of the first human family many thousands of years ago. Each branch, or lineage, arose in a different part of the world. For instance, the lineage called T, or Tara, probably came from Mesopotamia. The first T may have lived around the time when the last Ice Age was ending, ten thousand years ago or so. Each Daughter of Eve had a unique set of scores or mutations (see above) which they passed to their daughters, on and on, down to your mother.

What does modal match mean? This is the part of the world where the most people live today who have the same genetic scores as you. It is likely your ancestors once lived in that country or state (though not certain). The same word is used in polls and surveys: the modal response is what the greatest number of people said, for instance that they were strongly in favor, somewhat in favor or not in favor of something.

What does the map in my report show? First of all, it tells you whether your gene type is rare or frequent. Second, it tells you whether your gene type is widely spread or only found in certain areas around the world. Third, to the trained eye it can reveal the origins, history and migrations of your male line. For instance, in the pattern of distribution of the Western Atlantic Modal Haplotype (which is a form of R1b), some experts see the prehistoric movements of the Celtic people, some the beginnings of our modern-day Atlantic oriented culture, and some the footsteps of the barbarian hordes who overran the Roman Empire. Finding out the travels of your ancestors can be an exciting stimulus to learning more about history.

What is the difference between a haplogroup and haplotype? Haplogroups are the branches on the family tree of humanity, while haplotypes are the twigs. Haplogroups are either male or female. This depends on whether the Y chromosome or mitochondrial DNA was tested. There are thousands of haplotypes within each haplogroup just as there are thousands of twigs on one large branch.

If children have the same parents and receive the same haplogroups from them, why do they look different and have different family medical histories? Yes, for the same reason that some children are male and others female. Though we get exactly half our genes from our mother and half from our father, the choice between mother or father varies with each gene due to the recombinant nature of DNA. Sometimes the father will be the contributor, sometimes the mother. Because DNA is recombinant it combines in unique ways for each of the offspring. An over-simple way of saying this is that you might get your mother’s dark hair and your father’s blue eyes while your sibling gets your mother’s eyes and your father’s hair. Another sibling might have your mother’s eyes and hair.

How can you tell the history of my ancestors just from the scores on my DNA? A lot of science and a little art is involved, including a very detailed knowledge of medieval and ancient history plus a command of European languages. An excellent grasp of statistics is also required. Since the 1980s scientists have studied the genes of people all over the world. Their publications today are a gold mine for finding out where you fit in. Remember, though, each of us has a unique set of genes. No two people are completely alike or even closely similar as far as their genetic makeup is concerned. Biologically speaking, we are all true individuals, as were our ancestors.

The origin and meaning of my surname you give is not the same as I’ve been told — why? The study of surnames is a highly specialized field. No one can be sure they have received the right answers by just looking their surname up in a dictionary of names. There is a lot of false information out there. Many of the explanations are “folk etymologies,” in other words fictional. To judge what the true origins of a surname might be, one must be an expert not only in the history of the relevant region(s) but also in European languages, often including ancient languages like Latin, Greek and Hebrew. For example, even though they appear to be good old Anglo-Saxon names, many surnames in the British Isles are distorted French words. This is because of the overwhelming influence of the Normans, who invaded and conquered Britain in 1066.

What can I do now? You can share your report with your family and relatives. All results from the male tests are equally valid for your brother, if you have one, and any male-linked male relative of your father (uncle, cousin, etc.). They will be glad to get a free report! By the same token, all results from the female (mitochondrial) tests are valid for all your female-linked relatives (maternal aunt and the like), including both brothers and sisters. If you are female, you pass your mitochondrial DNA to all children, no matter if they are sons or daughters. Males receive mtDNA from their mothers, just as females do, although males cannot pass it. Only females pass mtDNA, and they pass it to all their children. Thus all the children of the same mother, whether full or half siblings, have her female lineage. You can post your DNA scores in any of a number of public databases or forums. You can also go beyond your direct male and direct female lines and take the DNA Fingerprint Test. Finally, you can always learn more. Read the suggested books and articles at the end of your report, join DNACommunities.com or delve into the resources on our site. Remember also you can contact us at any time with questions.

Your report is just the first step in a lifelong learning experience. Congratulations on being one of the first people to take this scientific journey of self-discovery!