Thomas A. Markham, Sr.
Y-DNA 37 TEST RESULTS
|29||YCA II b||23|
*Also known as DYS 394
**On 5/19/2003, these values were adjusted down by 1 point because of a change in Lab nomenclature.
My Y-chromosome results identify me as a member of Haplogroup R1b1c.
The genetic markers that define my ancestral history reach back roughly 60,000 years to the first common marker of all non-African men, M168, and follow my lineage to present day, ending with M343, the defining marker of haplogroup R1b.
If you look at the map highlighting my ancestors' rout, you will see that members of haplogroup R1b carry the following Y chromosome markers: M168 > M89 > M9 > M45 > M207 > M173 > M343
Today, roughly 70 percent of men in southern England belong to haplogroup R1b. In parts of Spain and Ireland, that number exceeds 90 percent.
What's a haplogroup, and why do geneticists concentrate on the Y chromosome in their search for markers? For that matter, what's a marker?
Each of us carries DNA that is a combination of genes passed from both our mothers and fathers, giving us traits that range from eye color and height to athleticism and disease susceptibility. One exception is the Y chromosome, which is passed directly from father to son, unchanged, from generation to generation.
Unchanged, that is unless a mutation a random, naturally occurring, usually harmless change occurs. The mutation, known as a marker, acts as a beacon; it can be mapped through generations because it will be passed down from the man in whom it occurred to his sons, their sons, and every male in his family for thousands of years.
In some instances there may be more than one mutational event that defines a particular branch of the tree, This means that any of these markers can be used to determine your particular haplogroup, since every individual who has one of these markers also has the others.
When geneticists identify such a marker, they try to figure out when it first occurred, and in which geographic region of the world. Each marker is essentially the beginning of a new lineage on the family tree of the human race. Tracking the lineages provides a picture of how small tribes of modern humans in Africa tens of thousands of years ago diversified and spread to populate the world.
A haplogroup is defined by a series of markers that are shared by other men who carry the same random mutations. The markers trace the path my ancestors took as they moved our of Africa. It's difficult to know how many men worldwide belong to any particular haplogroup, or even how many haplogroups there are, because scientists simply don't have enough data yet.
One of the goals of the five-year Genographic Project is to build a large enough database of anthropological genetic data to answer some of these questions. To achieve this, project team members are traveling to all corners of the world to collect more than 100,000 DNA samples from indigenous populations.