from ftdna.com ...
When you take a Y-DNA test for 12, 25, 37, or 67 markers, your test result is called a haplotype. In addition, you are provided with information on your haplogroup, or major population group. All members of a haplogroup descend from a common distant ancestor Family Tree DNA predicts your haplogroup based on the first 12 markers of your test result.
Examples of a haplogroup are the following: R1b, I1a, J2a2b, E1b1c, and R1a
Haplogroups represent the branches of the tree of Y-DNA. Every male in the world is on one of the branches of the tree. The branch of the tree is identified by SNPs, which is pronounced as "snips" (single nucleotide polymorphism). SNP testing determines your placement on the tree.
A haplogroup is defined as all the male descendants of the single person who first showed a particular mutation, called a SNP. These special mutations are extremely rare, and identify a group of people over a period of tens of thousands of years. Your haplogroup assignment indicates which part of the phylogenetic tree of male Homo Sapiens you descend from.
The major branches of the Y-DNA tree are labeled A through T. These branches then have sub-branches, which may in turn have sub-branches. The scientists created a naming system in 2002 to identify a position on the Y-DNA tree.
These names alternate letters and numbers, such as E1b1c. With this name, you can see exactly where a Y-DNA result resides on the Y-DNA tree Some haplogroups have more branches and twigs than other haplogroups. This is based on the SNPs that have been discovered and published.
A graphic representation of the 2008 Y-DNA Phylogenetic Tree can be
found here:
http://www.familytreedna.com/PDF/2008-HaploChart_GR_lores.pdf
For More Information: Haplogroup FAQ:
http://www.familytreeDNA.com/hap_explain.html
Y-DNA Haplogroup Nomenclature FAQ and links to prior Y-DNA tree:
http://www.familytreeDNA.com/hap_nomenclature.html
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. In the specific case of the LAKE DNA Project the European country of origin appears to be England for all members indicated to be of R1b.
Brief description of most current Y-chromosome haplogroups - (source: David Faux, Larry Sutton, Ken Nordtvedt, & paper by Dr. Rootsi, et. al., AJHG, "Phyleogeography of ... Haplogroup I ..., & RootsWeb DNA discussion group, 2004)
I,I1a, I1a1: Common in the Scandinavian/Viking populations, prevalent in northwestern Europe.
I1b, I1b2: Likely split from other I subclades in the western Balkans, "wintered LGM" with other I subclades in Franco/Iberia. Ref. Rootsi paper. Current high % in Sardinia.
I1c: Likely shares with I1a & I1b, a common Franco/Iberian habitat, post-LGM.
E3b: Believed to have evolved in the Middle East. (Semitic)
R1a: There's solid evidence that R1a is prevalent in western Norway in the "Viking era", and is today. Likely originated in the Kurgan culture of the Eurasian Steppes north of the Black and Caspian Seas.
R1b: Most common haplogroup in Europe. It contains the Atlantic modal haplotype. Prevalent in Celtic areas: Ireland, Wales, Scotland, Galicia, Brittany, Cornwall.
C: Found throughout mainland Asia, the south Pacific, and at low frequency in Native American populations.
C3: Southeast or central Asia origination.
O: Likely to have originated in southern east Asia and subsequently expanded to all of east Asia
J2: Northern portion of the Fertile Cresent. Cohen model haplotype. (Semitic).
D1: Found at highest frequencies in Middle Eastern and north African populations where it most likely evolved.
Q: Central Asia origination. Migrated though Altai/Baikel region of northern Eurasia.
O2: Has two primary lines, the 465 line and the M95 line. Both lines are found in Asia.
Q3: Native American
Historical Notes for R1b (source: David Faux, Ken Nordtvedt, & Rootsi paper, 2004.)
Haplogroup R1b (Hg1, P25*) It appears that during the Last Glacial Maximum (20000 years ago) R1b haplotypes over wintered in Northern Spain, and after the glacial retreat about 12000 years ago, began a migration to the north in large numbers, and to the east in declining numbers (although probably arriving in Spain from the east 30,000 years ago among the paleolithic or "old stone age" peoples considered to be aboriginal to Europe). This haplogroup is characteristic of pre-Celtic and Celtic populations including large areas of Scotland, probably including Orkney and Shetland 4000 years ago. R1b is the most common haplogroup in Europe and its frequency changes in a cline from west (where it reaches a saturation point of almost 100% in areas of Western Ireland) to east (where it becomes uncommon in parts of Eastern Europe and virtually disappears beyond the Middle East). A R1b haplotype is very difficult to interpret in that they are found at relatively high frequency in the areas where the Anglo/Saxon and Danish "invaders" originally called home (e.g., 55% in Friesland, and up to 30% in Norway). Thus a R1b haplotype makes it very challenging to interpret the origin of a family with this DNA signature. Marker DYS385a/b repeats of 11,14 are typical. However in Norway (and Iceland) profiles of 13/17 and 13/18 have never (or seldom) been seen in Celtic people, but are found uniquely in Norway and the countries they colonized.