International Society of Genetic Genealogyi's
DNA-NEWBIEi GLOSSARY |
| Genetic genealogy terms and definitions compiled and designed to be as simple and easy to understand as possible. Additional and more technical definitions are available on several other glossary websites. Terms and definitions are bookmarked to assist comprehension. |
A Administrator - Also known as a 'Project Administrator', 'Group Project Administrator', 'Project Manager', 'Coordinator' and 'Co-Coordinator'. A volunteer who establishes a DNA study with one or multiple commercial DNA testing companies. Admixture DNAi - The non-gender chromosomes that mix or recombine. Also known as autosomal DNA. Allele - (pronounced UH-leel) - The scientific result for a marker. Ancestral haplotypei - The method of deducing the MRCA's haplotype by comparing matching descendants' haplotypes, and eliminating the mutations. A minimum of three lines, as distantly related as possible, is recommended for deducing the ancestral haplotype. Ancestral state - Refers to the state of a SNP that has mutated and is shared by the most people. Example: A negative result on a SNP means it is ancestral, a positive result means it is derived. Anthrogenealogy - A term coined by Family Tree DNA combining the words 'anthro' and 'genealogy' in reference to utilizing DNA to trace one's heritage far beyond recorded documentation. Atlantic Modal Haplotype (AMH)i See Western Atlantic Modal Haplotype atDNAi - Acronym for Autosomal DNA. Autosomal DNA - The non-gender chromosomes that mix or recombine. Also known as admixture DNA. B Basei - The unit or building block of DNA. Adenine (A), cytosine (C), guanine, (G), and thymine (T) are the four bases in DNA. The order of bases is the sequence of DNA. Chromosomei - A structure found in the nucleus of a cell that contains genetic material. Humans have 23 pairs of chromosomes; 22 pairs of autosomes and one pair of sex chromosomes. CRS - Acronym for Cambridge Reference Sequence. The first mitochondrial DNA to be fully sequenced at Cambridge University in 1981. The anonymous donor of the CRS was haplogroup 'H'. Mitochondrial results are determined based upon where the results differ from the CRS. Deoxyribonucleic acid (DNA)i - A chemical consisting of a sequence of hundreds of millions of nucleotides found in the nuclei of cells. It contains the genetic information about an individual and is shaped like a double-stranded helix. Derived state - Refers to the state of a SNP that has mutated, usually in one man, from the ancestral state and created a new haplogroup or sub-clade of a haplogroup. A positive SNP result is derived, a negative SNP result is ancestral. DNAF - Acronym for DNA-Fingerprint - a commercial DNA testing company. DNAH - Acronym for DNA Heritage - a commercial DNA testing company. DNA-NEWBIE - A DNA-Newbie is someone who is new to the field of genetic genealogy. It is also the name of a Yahoo mailing list forum sponsored by the International Society of Genetic Genealogy. http://groups.yahoo.com/group/DNA-NEWBIE/ Double helixi - The twisted shape DNA forms when its two strands bond together. A double helix looks like a twisting or rotating ladder.DYS - Acronym for DNA Y-chromosome Segment - The assigned number of a marker on a segment of the Y-chromosome. Example: DYS# 393 Enzymei - A protein that facilitates a specific chemical reaction by working as a catalyst. FTDNA - Acronym for Family Tree DNA - a commercial DNA testing company. http://www.familytreedna.com Family Tree DNA Time Predictor (FTDNATiPTM) - A program used to calculate estimates of Time to the Most Recent Common Ancestor (TMRCA)i. It is the world's first calculator that incorporates mutation rates specific to each marker. This greatly increases the power and precision of estimates. GAPi - Acronym for the Group Administrator Page - This is a webpage in which a DNA Project Administrator utilizes functions such as creating a public website, generating a FTDNATiP report, etc. to assist project participants in coordinating results. GEDCOMi - Acronym for Genealogical Data Communications - A plain text program created for exchanging genealogical data between different genealogical programs. Family Tree DNA's 'My FTDNA' page, Y-Search and Mitosearch all contain a feature to upload a GEDCOM for pedigree comparisons to matches. Gene - A segment of DNA which contains the genetic code to make a certain protein or part of a protein. Generationi - The number of years between the birth of the parents and the birth of their children. Different studies use different numbers of years per generation. Family Tree DNA uses 25 years. Genetic Genealogy - The latest tool for genealogists utilizing DNA to aid genealogical research. Genographic Projecti - (pronounced GENE-o-graphic) - A five-year scientific genetics project launched in 2005 to study and map human migratory patterns. Along with testing indigenous populations, the project offers a 12-marker Y-chromosome or HVR1 mtDNA test for public participation with a portion of the proceeds benefiting the indigenous communities. The project is sponsored by National Geographic, IBM and the Waitt Foundation. Genographic participants have the option to join Family Tree DNA's database once their DNA results are in. Haplogroup - A group of similar haplotypes that share a common ancestor with a SNP mutation. Because a haplogroup consists of similar haplotypes, this is what makes it possible to predict a haplogroup. A SNP testi confirms a haplogroup. Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations, Example: R1b1. Y-chromosome and mitochondrial DNA haplogroups have different haplogroup designations. Haplogroups pertain to your deep ancestral origins dating back thousands of years. Haplotype - The term for the set of numbers that consists of your Y-chromosome or mitochondrial DNA results. Haplotypes are also known as signatures. HVR - Acronym for Hyper Variable Region - The sections of non-coding mitochondrial DNA that are used for genealogical DNA testing. ISOGG - Acronym for the International Society of Genetic Genealogy, a free society founded in 2005 for the promotion and education of genetic genealogy. JoGGi - The Journal of Genetic Genealogy - An online journal published quarterly with articles and features pertaining to genetic genealogy and anthrogenealogy. Junk DNA - Slang term usually used in referring to the non-coding region of DNA on the Y-chromosome. For more about: http://www.psrast.org/junkdna.htm Marker - A type of non-coding Y-chromosome DNA. The numbers designating your individual DNA segment numbers you receive with Y-chromosome DNA results. Example: 393=13. This means at marker #393, your allele value is 13. Meiosis i- The stage in which sperm and egg cells are formed. It is during this process that the autosomal chromosomes recombine and mutations occur. Mitosearch - A free public database sponsored by Family Tree DNA where mitochondrial DNA results from any testing facility may be uploaded and compared. Modal haplotypei - The most common result for each marker tested in a group of results. See also: ancestral signature. MRCA - Acronym for Most Recent Common Ancestor. mtDNA - Acronym for mitochondrial DNA. Mutation - A change in the DNA that occurs at random. Mutation is a scientific term that often connotes a negative connotation as a result of 1950's 'B' movies, but in genetic genealogy, a mutation is usually beneficial. Mutations on the Y-chromosome are often used for distinguishing different ancestral lines. Mutation ratei - The frequency with which random mutations occur. Non-coding DNA - Also referred to as "Junk DNA", non-coding DNA has no known biological function. Nuclear DNAi - DNA of chromosomes found in the nucleus of the cell. Null - A null is a value of zero on a marker. Nulls can occur due to missing genetic material on a marker, or a SNP can sometimes cause a null result. Several YSTR markers have been identified in certain families to have null results: 439, 448 OA - Acronym for Oxford Ancestors - a commercial DNA testing company. Organelle - A cell structure with specialized functions. Pherogrami - For STRs, a plot which shows the length of a fragment of DNA. This allows its allele value to be measured. Phylo-tree - Shortened term for Phylogenetic Tree - Most often used in reference to the available online diagrams connecting all Y-chromosome haplogroups. This term is also applied to DNA project diagrams created by Project Administrators utilizing specialized software. Polymorphism - See mutation. RAOi - Acronym for Recent Ancestral Origins (formerly known as REO - Recent Ethnic Origins) Recombination - An event occurring during meiosis - the formation of sperm and egg cells. One chromosome from the mother and the other from the father break and trade segments with one another. Sequencing - See DNA sequencing. STR - Acronym for Short Tandem Repeat - See: YSTR Sub-clade - Referring to a "branch" farther down the phylogenetic tree. Example: H3 -> '3' is a sub-clade of mitochondrial haplogroup 'H'. R1b -> '1b' is a sub-clade of Y-chromosome haplogroup 'R'. Sub-clade testing is also referred to as deep clade testing. Surname - A last name or family name traditionally passed down from father to son. Time to the Most Recent Common Ancestor (TMRCA) - The amount of time or number of generations since individuals have shared a common ancestor. Since mutations occur at random, the estimate of the TMRCA is not an exact number (i.e., 7 generations), but rather a probability distribution. As more information is compared, the TMRCA estimate becomes more refined. UUnique Event Polymorphism (UEP)i See single nucleotide polymorphism Western Atlantic Modal Haplotype (WAMH) The most common Y-DNA haplotypes found in Europe’s most common Y-DNA haplogroup, R1b. Whit's Predictor - The commonly applied nickname to the "Y-Haplogroup Predictor" created by Whit Athey. Enter Y-chromosome markers into the predictor and it will display percentages for matches to various haplogroups. X-chromosomei - The female gender chromosome, if a child receives one X from the father and one X from the mother, the child's gender is female. Y-Base - A free public database sponsored by DNA Heritage where Y-chromosome DNA results from any testing facility may be uploaded and compared. Y-chromosome - The male gender chromosome. In other words, only males have a Y-chromosome, which they receive from their father, who received it from his father, and so on. This transmission of the Y-chromosome down the male line is why it is useful for surname testing to determine if two males share a common ancestor. Y-DNA phylogenetic treei - A graphic representation of the Y-DNA haplogroups according to the YCC classification. Haplogroup names and major clades are labeled and mutation names are given along the branches of the trees. Y-Search - A free public database sponsored by Family Tree DNA where Y-chromosome DNA results from any testing facility may be uploaded and compared. YSTR - Acronym for Y-chromosome Short Tandem Repeat. The number of times the bases repeat that determines the value of the marker. Example: Thirteen repeats of the same bases equals a value of '13'. |
Glossary Websites: Kerchner's Genetic Genealogy Glossary National Geographic Genographic Project Genetics Glossary Family Tree DNA Glossary Genetics/DNA Glossary - Clan Lindsay ISOGG's Y-SNP Tree Glossary of Genetics Terms To purchase a comprehensive published glossary: |
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Used with ISOGG's permission
