R C Stubbs
« Reply #1 on: August 21, 2006, 03:59:41 PM »
Like most of us at the Stubbs DNA site, I too am learning about DNA applications to genealogy.
I guess the simplest way of comparing Haplogroup (defined by SNP mutations) and Haplotype (defiined by the number of STR values) is that Haplotype can be considered a more rapid mutation and is particularly useful in establishing relationships where the most recent common ancestor is within the past 200-300 years. Haplogroup involves a rarer type of mutation and is useful in attempting to establish very old lineages or ethnic origins.
STR mutations change from time to time and can be thought of as written in pencil on paper, that is, they may be erased and the number changed, due to more rapid mutations.
SNP mutations, on the other hand, are generally considered "carved in granite" and considerd to be a permanent mutation carried by all of the descendants of the man who first carried it.
As an example, on the Stubbs results page I am S-4. My Haplogroup is R1b1c, My Haplotype is the set of 37 numbers to the right of it. These haplotype numbers can be compared to those of others in the Stubbs group. My haplotype marker numbers are similar to those of S-2 and S-3, because we are 9th generation descendants of the same Stubbs ancestor.
Similarly, S-7, S-8, and S-10 are close in Haplotype values and are believed to also descend from the same common ancestor. These latter three haplotypes are significantly different from the first two, because they have a different ancestor.
Family Tree DNA has several pages of explanatory information on understanding DNA results. Ethnoancestry also has helpful information. Rootsweb.com also has a DNA forum.
I think the current price for a Haplogroup (deep clade) test at FTDNA is $79. This would be an upgrade from the haplotype tests.