Broadly, one of the alternative forms of a gene or genetic marker. More narrowly, the term allele value refers to a count of the number of repeats in an STR (pronounced ess-tee-are). A list of marker [..]

The designation given a SNP when DNA testing determines that the SNP mutation is absent.

The tracing of human lineage beyond the limits of historical records through DNA testing through the use of SNP testing to determine haplogroups.

A time frame of over 1000 to tens of thousands of years ago that predates recorded history and surnames for most people. The Y-DNA haplogroup tree traces SNP mutations over anthropological time.

The science of human beings, especially the study of human beings in relation to distribution, origin, and classification.

A small chemical molecule which is the information portion of the nucleotides in DNA. The chemical bases are: A (Adenine), T (Thymine) C (Cytosine) and G (Guanine).

A (Adenine) pairs with T (Thymine) and C (Cytosine) pairs with G (Guanine). These base pairs form the ladder of the DNA molecule.

A specific area on a haplogroup or phylogenetic tree that has associated SNPs. For example, E1, E2, and E3 are all branches of haplogroup E.

The self-replicating genetic structure of cells containing the cellular DNA that bears in its nucleotide sequence the linear array of genes. Chromosomes are normally found in pairs; human beings typic [..]

From the Greek word klados, meaning branch. A clade on the Y chromosome tree is also called a haplogroup.