A haplotype is a group of alleles in an organism that are inherited together from a single parent,[1][2] and a haplogroup (haploid from the Greek: ἁπλούς, haploûs, "onefold, simple" and English: group) is a group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation.[3][4] More specifically, a haplogroup is a combination of alleles at different chromosomes regions that are closely linked and that tend to be inherited together. As a haplogroup consists of similar haplotypes, it is usually possible to predict a haplogroup from haplotypes. Haplogroups pertain to a single line of descent. As such, membership of a haplogroup, by any individual, relies on a relatively small proportion of the genetic material possessed by that individual.