Y - HAPLOGROUPS: BACKGROUND

Each male Y chromosome is the descendant of one carried by a man who lived in East Africa perhaps 80,000 years ago.  Since   that time as humans moved about the planet, mutations known as single nucleotide polymorphisms (SNPs) have accumulated of the Y chromosomes of certain males in different regions of the world.  Thus a man residing in what is today Pakistan may have had a change of a single DNA letter, say an A to a T at a single spot on the chromosome.  All of his descendants will carry this harmless alteration in the "junk DNA".  However for population geneticists and genealogists this type of event has been a blessing.  It allows us to divide Y chromosomes into ancestral clusters known as haplogroups.  Thus if you are a descendant of a Scot whose ancestors in the male line were from the Pictish people described by the Romans, there is a high probability that you would have mutations at markers number M269, P25, M343, M173 and so on back to the signature carried by the early African ancestor.  It is now possible to assign each male to a specific category on the human "tree of life" which will indicate ancient ancestry.  The above Scot would be placed in category R1b1c according the the 2005 Y-Chromosome Phylogenetic Tree.  It indicates that his ancestors were likely Paleolithic Europeans who arrived from Central Asia to the Iberian Penninsula about 35,000 years ago.  In other words the Y-chromosome can tell its story, and point to the journey it has taken in time and space. 

If you have had your Y chromosome tested by one of the companies that specialize in microsatellite (Y-STR) short tandem repeat assessment, then you will have between 10 and 43 markers to assist in the quest to learn more about your ancestry.  However, these tests are only useful for comparing one signature to another and determining the probability of two people being related within a certain time frame.  It says nothing directly about your deep (ancient) ancestry.  You could look at your marker scores and say that they are similar to those who in fact have had specialized haplogroup testing, and since these individuals were from say Japan, then your ancestors much have originated there.  Unfortunately this is a faulty assumption since, for example, there is only a correlation between haplotypes and haplogroups.  The only way to know for sure what your haplogroup is, and therefore know something of your ancient ancestry, is to have the Y-chromosome subjected to specific haplogroup testing. 

Some companies will do very basic haplogroup testing such as testing for M170 which, if positive, would place a person in haplogroup category "I".  However, depending on one's goals, this is probably not going to be at all satisfactory.  For example, if you wish to know if your "I" is more likely from Norway, is native Briton, or is from the Balkans, then more "in depth" testing is needed.  It is imperative to know if one is I1a, I1b or I2.  With this knowledge, and an analysis of patterns on key Y-STR markers (e,g., DYS462 and DYS455) it may be possible to say with some authority that your I1a ancestors came from Scandinavia, and more specifically, likely Norway; that your I1b ancestor once lived in what is today Bulgaria; and that your I2 ancestor was probably living in the Border region between what is today England and Scotland at the time the Romans invaded.  Generally what will be offered is a firmer probability statement.  This is where a clear haplogroup assignment and a systematic Y-STR exploration can work hand in hand to increase the probability of learning the geographical origins of one's early (before the origin of surnames) ancestor resided.

Seldom can one say with 100% certainty that one's ancestors were, for example, Norse Vikings.  However knowing the haplogroup or SNP subgroup, and puting this together with other evidence such as surname or place of origin can often be conclusive.  An example is someone with the name Robertson who tests at M253  positive and whose male line ancestor came from the Shetland Islands.  Knowing from genealogical evidence that this man's ancestors used the Norse patronymic naming, and that Shetland was settled circa 800 AD by Norwegians for whom M253-I1a is a common haplogroup, then it is quite clear that this man can speak with authority about his Viking ancestors. 

The Haplogroup Basic and Supergroup Tests will assign each Y chromosome to one of the many major haplogroup or subgroups on the human phylogenetic tree as outlined by the Y-Chromosome Consortium (2002) and the updated Y-Chromosome Phylogenetic Tree (2005) published by the University of Arizona.  Unfortunately the research literature to date has published very little concerning the markers downstream from the major designators (e.g., M17-R1a1).  Your participation in testing with these markers would contribute to the knowledge base in an area where little is known.  If someone whose ancestors were Norse Vikings and M17 also tested positive for "downstream" markers observed at this point in Northern, Central and Southern Asia, then testing positive for any of these markers might support the hypothesis that some Central Asians migrated to Scandinavia, perhaps as the Roman Empire was breaking up circa 400 AD, to become the ancestors of some Scandinavians and their descendants in the colonies such as Iceland and Britain and from the latter to Australia and so on. 

Another example would be individuals who through haplogroup testing find that they belong to Haplogroup Q, which can be assessed via M45, M242, and M3.  If positive for M3 for example, and your ancestors were from the Americas, then there is essentially a 100% probability that they were Native American.  Some Native Americans are Haplogroup C so another complete set of markers would be needed to prove ancestry here - with the caveat that Haplogroup C (M216) is also found in Central and East Asia where it originated thousands of years ago and subclade testing with a series of other markers would be necessary to point to a Native American (e.g., to detect C3b) or Asian source. Customers can, if they wish, specify which markers they would like to be tested, or simply purchase the, for example, R1b "package" which includes all known markers beyond M269 or P25, the markers that defines the R1b general group.

To view the process whereby the technique of multiplexing is used to detect Y-SNP haplogroups, click here.

To view the output of the technique of direct sequencing to detect Y-SNP haplogroups, click here.