Some of us don’t quite understand the world of DNA. This first link below is a great introduction and should answer many questions: http://blairdna.com/dna101.html
There are two ways to test the Y-chromosome. The basic test is called STR (Short Tandem Repeat) and results in the series of marker values that most of us are familiar with - the surname test. Tests range from 12 to 67 markers. Each person’s set of marker values is called his haplotype
. These marker values are what place each of us in our respective lineages.
The second way to test the Y-chromosome is a SNP (Single Nucleotide Polymorphism), which is used to confirm one’s haplogroup
. A haplogroup consists of all the haplotypes whose ancestry converges on one person, usually a person who lived thousands of years ago. People of different haplogroups cannot be related. Another name for a SNP test is a “DEEP CLADE” test.
Both tests depend on mutations. Markers (STRs) mutate much more rapidly and are most valuable in determining a common ancestor who lived since the advent of surnames. SNP mutations occur more rarely and determine “deep ancestry.”
FTDNA can estimate one’s haplogroup from the haplotype (markers), but only a SNP test will provide positive identification of a haplogroup. Several in our Corbett/Corbitt study have already tested for the Deep-Clade, or SNP, test. The confirmed results are shown in GREEN in our Results table.
If you are interested in obtaining the Deep-Clade test, go to your personal MY FTDNA HOME, click on ORDER TESTS AND UPGRADES, and click on ORDER DEEP CLADE TEST.
Lastly, here is a great website that shows the migration of our “deep ancestry:” http://www.bradshawfoundation.com/journey/
Corbett/Corbitt DNA Studyjericorbitt@hotmail.com