Sifford Surname Project: Glossary

Sifford Surname Project: Glossary


One of the alternative versions of a gene or marker that can exist in a particular location on a chromosome.
deep ancestry
ancestors from more than a thousand years ago, sometimes tens of thousands of years ago.
genetic distance
A way of compressing the number of differences between the haplotypes of two participants into one figure that is easier to grasp.
DNA Y Segment; a number designating a given marker on the Y chromosome (e.g. DYS19, DYS390, etc.) These correspond to the headings of the tables shown here.
Haplogroups indicate 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. For a more thorough introduction to this subject, see Atlas of the Human Journey. A tree of Haplogroups, clades and subclades and their defining SNP's or "markers" is shown on the Y-DNA Haplogroup Tree 2006.
A set of closely linked alleles (genes or DNA polymorphisms) inherited as a unit. The line of data in the charts of this website for each participant constitutes the haplotype for that person. Haplotypes can be grouped together to suggest a common distant ancestor.
The designation or "name" of a SNP that defines a specific sub clade of Haplogroup E (E3b1a1).
The designation or "name" of a SNP that defines a specific sub clade of Haplogroup E (E3b1a2).
A gene or DNA sequence having a known location on a chromosome. On the tables presented here, each column represents a marker.
mitochondrial DNA
Genetic material passed on from mothers to all their children, but only daughters are able to passit on. Useful to genealogists for learning about their maternal roots.
Most Recent Common Ancestor
When two participants have closely matching haplotypes, it is possible to estimate the number of generations one would have to go back to their common ancestor. This calculation involves the Genetic Distance between the participants.
A change in a DNA sequence, in one or more markers, as passed from father to son. Normally, a specific marker is passed unchanged from one generation to another. Mutations allow genetic genealogists to define distinct family lines, since a mutation is then passed as changed to the next generation.
A Male Sifford (et al) who submits samples for the DNA study. Also referred to as "participant".
short tandem repeat
Each location, or marker, tested on the Y chromosome consists of a set of base elements repeated several times in the same sequence. The number of repeats provide a comparison between individual in genealogy.
Inter-individual variations in the genetic code at the level of one nucleotide, a building block of DNA. These variations occur so seldom they are used as the basis for forming haplogroups.
In this case, a subdivision of a haplogroup into sub-groups.
transmission event
A passing of DNA to the next generation; often used to refer to opportunities at which a mutation could have been introduced.
A method of estimating the probable Ancestral Haplotype by using the haplotypes of at least three (thus "triangulate") known lineal descendants.
The male chromosome, passed down from father to son essentially unaltered through the generations. The DNA analyzed for genetic purposes is "junk" DNA, and has no use in medical or forensic testing.

If you have / want further information, please contact the project administrators.

DNA tests by Family Tree DNA. Note: The project administrators are volunteer Sifford genealogists and are not paid by Family Tree DNA.

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