Glossary

A   B   C   D   E   F   G   H   i   J  k   L  M  N  o  p  q   R   s   T   u   v   w   XYZ    Home     Return

Link to Glossary at ftdna

 Aboriginal
Relating to a group of people indigenous to a geographic region; the original inhabitants of a region.

Adenine
The "A" of the four bases that make up DNA. The other bases are thymine (T), guanine (G) and cytosine (C). Adenine always pairs with thymine.

Admixture
Of mixed ancestry or mixed origins.

Allele  Pronounced uh-leel, the allele value is the number of times the sequence repeats in a certain location.  One of several forms of a gene that can exist at a single location (marker) on a chromosome. When STR's are measured on the Y-chromosome, this corresponds to a different number of repeat units. For example, for DYS19 where TAGA is the repeat unit, different alleles could be 13, 14, 15 repeats of the TAGA unit etc.  A father will pass his Y-chromosome on to his son and thus the son will inherit the same alleles (i.e. no. of repeat units).  Alleles will be changed if miscopied, resulting in a mutation. Some alleles are more common in particular populations.

Amplification
See DNA amplification.

Ancestral signature
The oldest known or hypothesized haplotype for a particular lineage. See also: modal haplotype.

Anthrogenealogy
The study of human origins, recent and distant, using DNA testing and genealogical methods.

Anthropology
The study of humans, particularly in terms of origin and culture.

Atlantic Modal Haplotype (AMH):  Also called the Western Atlantic Modal Haplotype (WAMH).  The most common Y-DNA haplotypes found in Europe’s most common Y-DNA haplogroup, R1b.  As one might expect the AMH is the most common haplotype in Europe. 
They are the following markers: DYS19 = 14, DYS388 = 12, DYS390 = 24, DYS391 = 11, DYS392 = 13, DYD393 = 13. 
In my table these markers are located at locus (location) 3-8-2-4-11-1.  They may be placed at other locus by different testing companys.


Autosomal DNA
The non-sex chromosomes. Humans have 23 pairs of chromosomes: the first 22 pairs are autosomal DNA and the 23rd pair consists of the sex chromosomes (the X- and Y- chromosomes).


 Base
The chemical unit or building blocks of DNA. Named Adenine (A), cytosine (C), guanine, (G), and thymine (T) are the four bases in DNA. 

Base pair
Bases pair up to form the "stairs" of the DNA double helix and always combine in the same patterns: A with T and C with G.  Two bases bonded together and attached to one of the strands in the DNA double helix.  The DNA bases are always held together in pairs and attached to one of the strands in the DNA double helix. The order of bases is the sequence of DNA.

Buccal cell
A type of cell found in cheek tissue inside the mouth.

 Cell The smallest unit of living matter that can operate independently.

Chromosomes are bundles of tightly coiled DNA. Humans have 23 paired chromosomes (22 pairs of autosomes and a single pair of sex chromosomes). A single chromosome of each pair is passed from each parent to child. 
A structure found in the nucleus of a cell that contains genetic material.

Cambridge Reference Sequence (CRS)
The mitochondrial DNA first sequenced in 1981 which is used as a basis for comparison with mtDNA test results.

Catalyst
A substance which starts or speeds up a chemical reaction without being affected by that reaction.

Coding region
A region of DNA which contains genes.

Cohanim Modal Haplotype

The Y-DNA haplotype most commonly found among males with an oral tradition of Cohen ancestry.

Cohen
The Hebrew word for priest which refers to a direct male descendant of Aaron, the brother of Moses; plural: Cohanim.

Combined DNA Index System (CODIS)
The CODIS system uses marker locations in the autosomal DNA. CODIS test results are maintained in an FBI database which is used to identify people and solve crimes.

Complementary sequences
Opposing strands of DNA which bond together to form the double helix. The bases always complement one another with adenine and thymine pairing together and cytosine and guanine pairing together.

Convergence
The process of two unrelated or less related lineages changing over time to resemble one another.

Cross-over
See recombination.

CRS (Cambridge Reference Sequence): (mtDNA): The mitochondrion sequenced in 1981 became known as the Cambridge Reference Sequence (CRS) and has been used as a basis for comparison with your mtDNA. In other words, any place in your mtDNA where you have a difference from the CRS is characterized as a difference or mutation.  (See also RSRS)

Cytosine
The "C" of the four bases that make up DNA. The other bases are adenine (A), guanine (G), and thymine (T). Cytosine always pairs with guanine.


 Darwin, Charles
His work became the foundation of modern evolutionary theory. Charles Darwin's 1859 book The Origin of Species promoted a theory of evolution by natural selection and challenged Victorian-era ideas about the role of humans in the universe. Darwin's theories were based on a constantly evolving natural world and held that each generation of a species had to compete for survival. Survivors held some natural advantages over their unfortunate relatives and passed those characteristics on to their progeny, thus over-representing these favored genetic types in the next generation. Darwin also advanced the idea that species were descended from a common ancestor. Darwin's work became the foundation of modern evolutionary theory.

Deletion: (mtDNA) A deletion takes place when a base pair is removed from the sequence.  

DNA (Deoxyribonucleic Acid): The double helix-shaped molecule that holds an organism's genetic information. DNA is composed of sugars, phosphates, and four nucleotide bases: adenine, guanine, cytosine, and thymine (A, G, C, T). The bases bind together in specific pairs (see detailed entry below).  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.   Known by many as the structure of heredity, DNA is a chemical consisting of a sequence of hundreds of millions of nucleotides found in the nucleus of cells. It contains the genetic information about an individual and is shaped like a double-stranded helix.   Known by many as the structure of heredity, DNA is a chemical consisting of a sequence of hundreds of millions of nucleotides found in the nucleus of cells. It contains the genetic information about an individual and is shaped like a double-stranded helix.

DNA amplification
The production of many DNA copies from one or a few copies or fragments.

DNA replication
The process by which the DNA double helix makes a copy of itself or of a fragment of itself. It uses the old DNA as a template for the synthesis of new DNA strands. In humans, replication occurs in the cell nucleus.

DNA sequencing
The process of determining the exact order of the nucleotide bases in a segment of DNA.

DNA Y-chromosome Segment (DYS)
The "name" of a marker on the Y-chromosome. It is assigned based on a nomenclature system controlled by the HUGO Gene Nomenclature Committee, which assigns DYS numbers to newly discovered markers.


Double Helix
: The double helix-shaped molecule holds an organism's genetic information.  The twisted shape of DNA, when its two strands bond together, much like a spiral staircase or twisted ladder. The stairway's railings are composed of sugars and phosphates. Its sides contain the patterned base pairs: A, T, C, and G. When a cell divides for reproduction, the helix unwinds and splits down the middle like a zipper in order to copy itself.

DYS
D = DNA: Y = Chromosome; S = Single copy sequence. The DYS numbering scheme (e.g. DYS388, DYS390) for the Y-STR haplotype markers are controlled and administered by an international standards body called HUGO - Human Gene Nomenclature Committee - based at University College, London.

 Enzyme
A protein that facilitates a specific chemical reaction by working as a catalyst.

Exact match
Two individuals with exactly the same results for all markers or regions compared.


 Family Tree DNA Time Predictor (FTDNATiPTM)
A program used to calculate estimates of Time to the Most Recent Common Ancestor (TMRCA). It is the world's first calculator that incorporates mutation rates specific to each marker. This greatly increases the power and precision of estimates.


FOXP2
: The first gene to be linked to language production, and the key to the development of brain regions associated with speech. FOXP2's discovery suggests that the development of language may be tied to a genetic mutation that could have occurred some 50,000 years ago, in the same time range as the first great human migrations out of Africa.

 Gene the functional and physical unit of heredity passed from parent to offspring. 
A segment of DNA which contains the genetic code to make a certain protein or part of a protein.

Genes
: Segments of DNA that are the basic functional units of heredity. Genes are determined by an ordered sequence of chemical bases found in a unique position on a specific chromosome. Their "blueprint" guides protein production, which determines how different cells in the body function. Inherited genes also control an animal's unique set of physical traits.

Genealogical Data Communication (GEDCOM)
A type of file format used by genealogical software to make your family tree. You can upload your GEDCOM file to your Family Tree DNA personal page as well as Ysearch or mitosearch. Learn more about GEDCOM here

Genealogy
The study of family history.

Generation
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. At Family Tree DNA we use 25 years.

Genetic cousins
Individuals whose Y-DNA or mtDNA test results match one another.

Genetic distance
The number of differences, or mutations, between two sets of results. A genetic distance of zero means there are no differences in the results being compared against one another (exact match).

Genetics
The study of genes and heredity; the study of DNA.

Genetic Marker
: Random mutations in the DNA sequence which act as genetic milestones. Once markers have been identified they can be traced back in time to their origin—the most recent common ancestor of everyone who carries the marker.

Genome
: The total DNA sequence that serves as an instruction manual for all proteins created in our body. Two copies of the genome are found inside each of our cells.  The entire complement of genetic material in a chromosome set. The human genome is composed of 46 chromosomes, with a total of 3 billion base pairs.

Genotype
the actual alleles present in an individual.  Haplotype is a genotype of genetically linked loci that are inherited in a block as a single unit.  Modal Haplotype (MH) Definition: any person who exactly matches the alleles found to be most common (Modal) among the descendants of a person. A person who matches 20 alleles while being 1 allele off in only 1 locus will be considered to be in the haplogroup, rather than in the family haplotype.

Glacial maximum
The scientific term for the peak of an ice age.

Guanine
The "G" of the four bases that make up DNA. The other bases are adenine (A), cytosine (C), and thymine (T). Guanine always pairs with cytosine.

 Haplogroup: Branches on the tree of early human migrations and genetic evolution. Haplogroups are defined by genetic mutations or "markers" found in Y chromosome and mtDNA testing. These markers link the members of a haplogroup back to the marker's first appearance in the group's most recent common ancestor. Haplogroups often have a geographic relation.  Haplogroups are large groups that can be used to define genetic populations and are often geographically orientated. For example, when the Y-chromosome is tested, many males who live along the western coasts of Europe belong to Haplogroup R1b (used to be called HG1), which belies the historical movement of males along that coast.

The Y-chromosome haplogroup of an individual is
not defined by their haplotype (because haplotypes are determined by STR markers). Instead, they are determined by SNP's (single nucleotide polymorphisms) where a single base changes e.g. from A to G. These happen so rarely as to be considered unique.

However, there is a strong correlation between haplogroups and haplotypes so given any particular haplotype, it may be possible to correctly determine the haplogroup without any further tests (see Masterclass).

It is important to note that even though female and male haplogroups may have the same letters, their definitions are different.

The matches listed on your personal Haplotree Matches page are determined by comparing your first 12 markers, not your SNPs.   So the Haplotree Matches page is saying that you have two exact 12-marker matches who have done SNP testing to determine their haplogroups -- one may be R1b1a2a1a1b3 and the other may be R1b1a2a1a1b5a.   This page is intended to give you a general idea about what your haplogroup might be, based on a 12-marker comparison with your matches. However, since 12-marker matches are extremely broad, it's definitely possible (and even common) at that level for your matches to be in different subclades than you, as is the case here.


Haplotype
Your Y-DNA haplotype is a set of 21 numbers (if using 21 STR markers), each number representing your allele at a given STR marker. Two or more haplotypes may be compared as a check for a genetic relationship. 
Two individuals that match exactly on all markers have the same haplotype.

There are many haplotypes to be found from many different populations around the globe at www.yhrd.org that may be used to compare haplotypes. Also, the Ybase database can accept genealogical as well as haplotype data.


Haplogroup Descriptions
N1  This haplogroup is distributed throughout Northern Eurasia. It is the most common Y-chromosome type in Uralic speakers (Finns and Native Siberian). This lineage most likely originated in northern China or Mongolia and then spread into Siberia where it became a very common line in western Siberia.
R1  The undifferentiated R1 lineage is quite rare. It is found only at very low frequencies in Europe, Central Asia, and South Asia. This lineage possibly originated in Europe and then migrated east into Asia.
R1b  Haplogroup R1b is the most common haplogroup in European populations. It is believed to have expanded throughout Europe as humans re-colonized after the last glacial maximum 10-12 thousand years ago. This lineage is also the haplogroup containing the Atlantic modal haplotype.
R1b1   This lineage is also the haplogroup containing the Atlantic modal haplotype.
R1b1b2   This lineage is also the haplogroup containing the Atlantic modal haplotype.
R1b1b2d Its branch R1b1b2d is found primarily in the British Isles, but can also be found at lower frequencies around Western Europe.
R1b1b2e Its branch R1b1b2e is primarily found in Northern Ireland, and contains the Niall Modal Haplotype.
R1b1b2g Its branch R1b1b2g is distributed across Europe.
R1b1b2h   Its branch R1b1b2h is distributed across Europe.
All Contents Copyright 2001-2007 Genealogy by Genetics, Ltd.

Haplotype diversity
A measure of the uniqueness of a particular haplotype in a given population.

Heredity
: The total sum of genetic information that humans pass on from generation to generation.  The transmission of genetic material from parents to offspring.

Human Genome Organization (HUGO)
The entity to which, among other things, scientists submit new markers for DYS number assignment.

HVR1 and HVR2 (HyperVariable Region 1 and 2): The two sections or regions of the mtDNA which are tested in the mtDNAPlus test. The results can be used to determine a person’s ethnic and geographic origins, as well as to look for possible common ancestry with other individuals.

Hypervariable Region (HVR)
One of two regions commonly used in mitochondrial DNA tests which does not code for any known function.

1. What are the parts of the mitochondrial DNA (mtDNA)? FTDNA faq id: 483
Mitochondrial DNA (mtDNA) has two major parts, the control region and the coding region.
The control region is often called the hypervariable region (HVR). Hypervariable means fast changing. In mitochondrial DNA the control region is the fast changing part.

2. What are HVR1 and HVR2?
The control region may be further divided into two Hypervariable regions, HVR1 and HVR2.
HVR1 runs from nucleotide 16001 to nucleotide 16569.
HVR2 runs from nucleotide 00001 to nucleotide 00574.

3. What is the Coding Region?
The coding region (CR) is the part of your mtDNA genome that contains genes.
Because it does contain some genes, the coding region is believed to be slower mutating than the control region.   Often, it is the mutations that are found in the coding region that are used to define haplogroups.  The coding region runs from nucleotide 00575 to nucleotide 16000.

4. What are "low resolution matches"? FTDNA faq id: 484
An exact match on the first hypervariable region, HVR1, is sometimes called a low resolution match.  When the match also shares the same haplogroup it indicates a possible connection. An HVR1 match has a 50% chance of a common maternal ancestor within the last fifty-two generations or about 1,300 years.

When an HVR1 match belongs to a different haplogroup it is due to convergent evolution. That is when by coincidence two different lineages mutate to look alike.  [This seems to be saying to compare HVR1 and HVR2 only within your Haplogroup].

5. What are "high resolution matches"? FTDNA faq id: 485
An exact match on both the first and second hypervariable regions, HVR1 and HVR2, is sometimes called a high resolution match. When they also share the same haplogroup it indicates a possible connection.   A match on HVR1 and HVR2 means that you have a 50% chance of a common maternal ancestor within the last twenty-eight generations or about 700 years.

When they have different haplogroups it is due to convergent evolution. That is when by coincidence two different lineages mutate to look alike.   [This seems to be saying to compare HVR1 and HVR2 only within your Haplogroup].

6. How many generations back does mitochondrial DNA (mtDNA) testing trace? FTDNA faq id: 486
Mitochondrial DNA (mtDNA) testing covers both recent and distant generations.   To find connections in recent times it is necessary to find and test multiple people who have suspected shared ancestry.  This is done by careful examination of traditional genealogical records.  Making connections with people in genealogical and historic interest groups can also be helpful.

Matching on the Mitochondrial DNA Full Genomic Sequence (FGS) test brings your matches into more recent times.   It means that you have a 50% chance of sharing a common maternal ancestor within the last 5 generations. That is about 125 years.
Mitochondrial DNA testing at Family Tree DNA also includes haplogroup testing. Your haplogroup represents your ancestral origins thousands to tens of thousands of years ago.

7. Why do I have so many mitochondrial DNA (mtDNA) test matches? FTDNA faq id: 489
There are some result haplotypes that show a high number of matches. There are two possible explanations for this.
a. Many people with the same results as your ancestors lived thousands or tens of thousands of years ago. The majority of their descendants still carry their signature.
b. A more recent common ancestor — within the last one or two thousand years — with this haplotype had many daughters who in turn had many daughters and so on leading to you having many distant cousins.

8. Increasing your testing level to the Mitochondrial DNA Full Genomic Sequence (FGS), the "HVR1toMega" or the "HVR2toMega upgrade", will separate these two cases. This will allow you to focus on your relevant matches.

Insertion: An insertion takes place when a base pair is added to the sequence.

Junk DNA
Stretches of DNA that do not code for genes, also called non-coding DNA. Most of the genome consists of non-coding DNA, and was therefore long thought to be 'junk.' Scientists have found that in addition to containing markers that are helpful for genetic genealogy, parts of these non-coding regions have regulatory and other functions.


Link to Golssary at FTDNA web site

 Locus (pl. loci) 

Loci  The plural of locus, or marker. Locus and loci are Latin words for location(s).

Locus (plural-loci)  Latin for place. A specific spot in the genome.  A variable locus will have several possible alleles.  See marker. 

 Marker
Also called a Locus (pl. loci). A gene of a known location on a chromosome. See STR marker. The DNA Heritage Y-DNA test uses 21 STR markers. 
Family Tree DNA offers 3 levels of Y-DNA testing: 12-marker,  37-marker, and 67-marker.

Meiosis
The stage in which sperm and egg cells are formed. It is during this process that the autosomal chromosomes recombine and mutations occur.


Melanin/Vitamin D/Skin Color
: Melanin, the skin's brown pigment, is a natural sunscreen that protects tropical peoples from the many harmful effects of ultraviolet (UV) rays. But when UV rays penetrate the skin they also produce beneficial vitamin D, so some exposure to them is necessary. This delicate balancing act explains why the peoples that migrated to darker, colder climes also developed lighter skin color. As people moved to areas with lower UV levels, their skin lightened so that UV rays could penetrate and produce essential vitamin D. In some cases a third factor intervened. Coastal peoples who eat diets rich in seafood enjoy an alternate source of vitamin D. That means that some Arctic peoples, for example, can afford to remain dark-skinned even in low UV climes.

Microsatellite
See short tandem repeat.


Mitochondria
: A remnant of an ancient parasitic bacteria that now helps to produce energy inside the cell. A mitochondrion has its own genome, present in only one copy, which does not recombine in reproduction. This genetic consistency makes mitochondrial DNA a very important tool in tracking genetic histories.  A specific organelle in the cell that helps it to produce energy.

Mitochondrial DNA or mtDNA
: The genetic material found in the mitochondria. It is passed from females to their offspring without recombining, and thus is an important tool for geneticists.  It is passed down from females to both sons and daughters, but sons do not pass down their mother's mtDNA to their children.

Modal comes from the statistical term Mode, which means the value at which an absolute or maximum occurs in the frequency distribution of the variant.

Modal haplotype
The most common result for each marker tested in a group of results. See also: ancestral signature.

Modal Associations of the R Haplotypes



Most Recent Common Ancestor (MRCA)
The ancestor shared most recently between two individuals.

mtDNA is passed down from females to both son and daughter, but sons do not pass down their mother’s mtDNA.

Mutation
A heritable change that occurs in genetic material. It may lead to a different number of repeats of a certain sequence or a change in one of the bases in a sequence.   A heritable change that may occur in a gene or in a chromosome and may take the form of a chemical rearrangement or a partial loss or gain of genetic material.

Mutation rate
The frequency with which random mutations occur.


 Nucleotide
: A DNA building block which contains a base, or half of a "staircase step," and sugars and phosphates which form the "railing." Nucleotides join together to form DNA's distinctive double helix shape.  A piece of DNA that contains one base, one phosphate group, and one sugar unit. Thousands of nucleotides joined in sequence make a molecule of DNA.

Nucleus
: The part of the cell in which chromosomes reside.  The membrane-bound organelle containing the chromosomes.

Pherogram
For STRs, a plot which shows the length of a fragment of DNA. This allows its allele value to be measured.

Phylogeny: The evolutionary development of a species. Phylogeny is sometimes represented as a tree that shows the natural relations and development of all species.


Point Mutation
a change in a single base pair.


Population genetics: The study of genetic variation in a species.

Proteins: Linear sequences of amino acids that are the building blocks of cells. Each protein has a specific function that is determined by the "blueprint" stored in DNA.

Phylogenetic tree
See Y-DNA phylogenetic tree.

Polymerase
The enzyme that starts the process of making nucleic acids or assembling RNA or DNA.

Polymerase Chain Reaction (PCR)
A technique allowing the production of multiple copies of extremely small amounts of DNA fragments using DNA polymerase and specific primers.

Polymorphism
A mutation, or change, in the DNA sequence which is inheritable.

Primer
A short DNA sequence used in the polymerase chain reaction to initiate DNA synthesis at a particular location.

Protein
The main building block of our cells. Each one has a specific function.


 
Recombination
: The process by which each parent contributes half of an offspring's DNA, creating an entirely new genetic identity. This process mixes genetic signals, so that nonrecombining DNA, passed intact through the generations, is most important to population genetics.  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.

Replication: The process by which two DNA strands separate, with each helping to duplicate a new strand. During reproduction, the DNA double helix unwinds and duplicates itself to pass on genetic information to the next generation. Because bases always form established pairs (AT and CG), the sequence of bases on each strand will attract a corresponding match of new bases. Only occasional errors occur—about one for every billion base-pair replications.  See DNA replication.

RNA (Ribonucleic Acid): Transfers the genetic "blueprint" that is stored in DNA during protein production. RNA has a single-stranded linear structure and a slightly different chemical composition from DNA.

Restriction enzyme
A protein that recognizes a certain sequence of DNA and cuts the DNA at that site.

Restriction Fragment Length Polymorphism (RFLP)
See single nucleotide polymorphism.

RSRS (
Reconstructed Sapiens Reference Sequence): Family Tree DNA is staying on top of the latest advancements in genetic genealogy, adding a new way of reporting our mitochondrial DNA.   In April of this year a paper by Doron Behar (et al) was published proposing a new method of reporting mtDNA. This new method uses mutations referenced to a Reconstructed Sapiens Reference Sequence (RSRS) instead of the traditional revised Cambridge Reference Sequence (rCRS).   In this study, we propose a “Copernican” reassessment of the human mtDNA phylogeny by switching to a Reconstructed Sapiens Reference Sequence (RSRS) as the phylogenetically valid reference point.   The aim is to trigger the radical but necessary change in the way mtDNA mutations are reported relative to their ancestral/derived status, thus establishing an intellectual cohesiveness with the current consensus of shared common ancestry of all contemporary human mitochondrial genomes.  Posted 4/3/2013 - Reference http://www.yourgeneticgenealogist.com/2012/07/family-tree-dna-adds-new-rsrs-reporting.html

Sequencing: Determines the order of nucleotides for any particular DNA segment or gene. The order of a DNA string's base pairs determines which proteins are produced, and thus the function of a particular cell.  See DNA sequencing.

Sex chromosome
The X- or Y-chromosome. Normally males have one X and one Y and females have two Xs.

Sexual Selection: Special form of natural selection based on an organism's ability to mate. Some animals possess characteristics that are more attractive to potential mates, such as the distinctive plumage of some male birds. Individuals with such characteristics mate at higher rates than those without, ensuring more next generation offspring will inherit the desirable trait. As generations procreate the desirable trait becomes increasingly common, further boosting the sexual disadvantage for individuals who lack the desired trait. The effect can be particularly dramatic when one individual controls mating with a large number of potential partners.

Short Tandem Repeat (STR)
A short DNA motif (pattern) repeated in tandem. ATGC repeated eleven times would give the marker a value or allele of 11.


SNP: Single Nucleotide Polymorphism: Small, infrequent changes which help to create an individual's own unique DNA pattern. When a single nucleotide (A, T, G, or C) in the genome sequence is altered during DNA replication, due to a tiny "spelling mistake," the genome sequence is altered.  A person has many SNPs that together create a unique DNA pattern for that individual.  
SNP tests are able to trace both ancient anthropological migrations and more recent prehistoric movements. A Y-DNA SNP test also identifies the haplogroup, which represents your deep ancestral origins (tens of thousands of years ago).

STR (Short Tandem Repeat) A region of repetitive DNA with short units of repetition (2 to 6 basis).  STR tests are able to trace a male lineage within genealogical times and into historic times.  Your genealogical connections will be shown on the Y-DNA – Matches page of your myFTDNA account.  The Y-DNA – Ancestral Origins page of your myFTDNA account will point towards possible countries of origin.*

Surname
A last name or family name traditionally passed down from father to son.

Thymine
The "T" of the four bases that make up DNA. The other bases are adenine (A), cytosine (C), and guanine (G). Thymine always pairs with adenine.

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.


TMRCA this term used by population geneticists indicates the Time to the Most Recent Common Ancestor shared with another person.

Trait
: The physical characteristics, like eye color or nose shape, which are determined by inherited genes.

Transmission event
The passage of genetic material from one generation to the next.

Unique Event Polymorphism (UEP)
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.

 X and Y Chromosomes: Chromosomes which determine sex. Females have two X chromosomes while males have one X and one Y. When chromosomes pair, the mismatched Y determines male gender. Because of the mismatch, part of the Y chromosome does not recombine with the X during reproduction. The nonrecombining part of the Y chromosome contains a sequence of DNA passed intact from males to their sons through the generations, giving population geneticists a useful tool for studying human history.  The Y-chromosome passes down from father to son. Females do not receive it. The fact that the Y-chromosome goes down the paternal line makes it valuable for genealogy studies, since it typically follows a surname line.

Y-chromosome
The sex chromosome that instructs a foetus to grow into a baby boy. It is passed down from generation to generation only through the male line i.e. from father to son, father to son, etc. It is approx. 60 million base-pairs long.

Y-DNA non-recombining DNA determines whether a child will be a male or female. Y-DNA passes from father to son almost unaltered for long periods of time.

Y-DNA phylogenetic tree
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-DNA Step-mutations
When comparing the results of Y-Chromosome STR (short tandem repeat) tests, the difference between the two values at a marker is the Y-DNA genetic distance or the step-mutation count. That is, a one-step mutation means that the count for a single STR has changed by one. A two-step mutation means that the count for a single STR has changed by two
 


I have decided not to put my actual data on my web - As soon as I understand this stuff I will write-up a report.

Home    Return     Top