This begins a series of messages to help all of us better understand
the implications of DNA on our family research. These messages will
be taken from a newsletter published periodically by Family Tree DNA.
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What will Genetic Genealogy do for your research?
The term Genetic Genealogy refers to the application of science,
through testing DNA, to uncover information about your ancestors.
There are currently two types of tests available to the general
public: the Y-DNA test and the mtDNA test. The Y-DNA test tells you
about your male ancestors, and the mtDNA test tells you about your
The Y-DNA test is for males only as it tests the Y chromosome, which
is only found in males and is inherited from the father's direct
paternal line (grandfather to father to son). Scientists have
determined that the Y chromosome is passed from father to son
unchanged, except for random mutations that are estimated to take
place only once per 500 generations per marker.
The direct line of descent for males is critical. Events such as
adoption or an extramarital male birth would break this chain.
All males with a direct line of descent from your most distant known
male ancestor should have the same Y chromosomal pattern, or genetic
fingerprint, except for the random mutations. If you compare the
genetic fingerprints of these male descendents today, they should
How can this help you in your research? Testing the Y chromosome can
verify what is known. It can point you in a direction for further
research, or prove or disprove a relationship or theory. Family Tree
DNA's Y-DNA test can find others to whom you are related. It might
point you to a specific geographic location for further research.
The individual reasons for doing Y-DNA testing vary significantly,
from curiosity to specific genealogical research goals to large
Here are just a few examples of the use of Y-DNA testing. For
example, suppose two immigrants, who came to the U.S. in 1740, had
the same surname, but you can't connect them. By testing direct male
descendents of each immigrant, you can determine whether or not the
two immigrants were related. In another situation, your family
legend is that your surname was changed on immigration. All persons
with the new surname found in the US fit into your tree. Your
grandfather gave you two possible original surnames. By testing
descendents of the two possible original surnames, you could
determine if you were related to either. In another example, you
have found your surname in New Zealand, and those people come from
the same County in Ireland. By testing both groups, you can
determine if they are related, and perhaps you will focus more
research in this Irish county for paper records. In many cases, you
may only need as few as two participants to apply Y-DNA testing to
solving your genealogy brick walls or adding more information to your
Y-DNA Surname Projects attempt to test all lines, branches and
variants of a particular surname to determine which are related.
Surname Projects can start small with a subset of the surname and be
expanded in phases.
The mtDNA test is available for females and for the female ancestors
of males. We all carry mtDNA inherited from our mothers.
Anthropologists have determined that there exist approximately 20
daughters who are descended from a single 'mitochondrial Eve.'
Family Tree DNA's mtDNA tests will determine from which daughter of
Eve you descend. You can then use the Family Tree DNA database to
find others whom you match
Facts & Genes from Family Tree DNA
July 24, 2002 Volume 1, Issue 1; Copyright 2002, Family Tree DNA