Haplogroups to Haplotypes

Our human genome has been around a long time.  Since its beginning, any random, permanent change in the DNA molecule has been called a "mutation".  A change in one nucleotide base pair represents a "point mutation", and is referred to in genetic lingo as "single nucleotide polymorphism" or "SNP" which is pronounced "snip".  The Y-chromosome is the smallest of those DNA chains called chromosomes, and is least likely to undergo mutations among all 46. [ that male stubbornness I guess]  Once a single base pair mutates, it becomes a distinct marker for that chromosome.  This marker is then past along among the male descendants.  These markers have been identified, and have come to be called "haplogroups".   They have been labeled using the alphabet A thru T, with "haplogroup A" starting things off.   The following chart shows these haplogroups starting around 60,000 BC.

As time has progressed, these haplogroups have undergone additional genetic changes, at various additional sites, involving multiple nucleotide bases. [Whew...can you keep that straight]  These are again random chances but involve at least two base combinations next to one another (tandem) or at different (variable) sites along the DNA molecule.  These additional changes among the "haplogroups" are called "haplotypes".  The number of haplotypes vary, and those haplogroups with the highest number of haplotypes are shown in the figure above.

Haplogroup "E" has the highest number of haplotypes with 58.   This is followed by haplogroup "J" with 34, and haplogroup "O" with 31.  My JONES surname haplogroup "R" comes in forth with 29 haplotypes.

Now if you take the number of haplogroups and divide by the number of "1000 year of existence", you come up with a ratio of mutations per thousand years!   For example, if you take haplogroup "E" with its 58 haplotypes and divide by 50 [ the number 50,000/1000 = 50] you get a ratio of 1.16 mutations per 1000 years.  If you take my JONES haplogroup "R" [29 divided by 30,000/1000 ] you get a ratio of .967 per 1000 years.  However, if you take haplogroup "J" [ 34 divided by 25,000/1000] you get a ration of 1.36 mutations per 1000 years.  How about that...you get roughly 1 mutation per 1000 years for the haplogroups.  Haplogroups to haplotypes...part of our human family tree.

Data taken from "Y-Chromosome Phylogenetic Tree" from Genome Research and Family Tree DNA.

Tag Your It

Recent changes in the classifications of my haplotype, R1b1b to R1b1a2, made for some interesting additional questions. What in the world does this mean!?...was the first. I had spent a fair amount of time shifting through the data on R1b1b. It pointed me to Wales. What does this change do?

The International Society of Genetic Genealogy (ISOGG) and Family Tree DNA (FTDNA) seemed to have a slightly different view. Apparently it was FTDNA that first made the changes in their haplotype classification. [Where I had my DNA tested.] This was based upon the identification (clarification) of a specific sub-group [called "sub-clade"] of R1b. This sub-group demonstrated (dominated by) a specific genetic marker tagged R-m412. It was found on those who carried the R1b1b marker tagged R-m269. This sub-group [sub-clade ] was found in Wales 92.3 % of the 65 people studied! Wow, I made it home! This change in classification showed that my genealogy work of more than 50 years was again supported. My genes exposed. Another change is possible before all this gets straighten out. Tag your it!

Haplogroups to Haplotypes

As discussed in a previous post (Terms, Terms, and more Terms), a haplotype is defined by as series of changes among several nucleotides in a row. Since the changes occure side by side, they are called "Short Tandem Repeat" or STRs. At the biochemical level where these changes occur and have been identified, there has been applied a naming system. [Human Gene Nomenclature Committee] This naming system includes an address (locus); a DYS # (DNA, Y-chromosome, [unique] segment); and an "allele" value. [An allele is one side of the DNA double helix.]

The figure to the right is an addition to "The Gene Tree-Haplogroups", showing the number of haplotypes for each of the haplogroups. At the top, the number of haplotypes in each haplogroup is shown along the approximate time frame. At the bottom, the number of haplotypes are given under the haplogroup in which they are derived. Haplogroup E has the greatest number of haplotypes at 58! Haplogroup J is second in number of haplotypes (34), followed by haplogroup O (31) and haplogroup R (29). My JONES DNA belongs to haplogroup R. Certainly, it is an interest "Gene Tree"!