Hello,
Recently off list I was asked about atDNA or autosomal DNA testing and why the low
response rate for queries in the Ancestry system. Below is from that off line email.
The Carpenter Cousins Y-DNA Project focuses on the male Y-chromosome that is passed down
virtually unchanged over the generations. This type of DNA is excellent for surname
studies.
Many members also have tested their autosomal DNA (atDNA) but mainly with FamilyTree DNA
(FTDNA). The Ancestry DNA test is also atDNA. People who test their atDNA from various
DNA testing companies can use
GEDMATCH.com.
GEDmatch provides DNA and genealogical analysis tools for amateur and professional
researchers and genealogists. Most tools are free, but GEDMATCH does provide some premium
tools for users who wish to help support them with contributions.
For a comparison of the different DNA tests and which companies provide such tests, please
see A) below.
Personally I have tested my Y-DNA (111 markers), mitochondrial DNA (mtDNA HVR1 &
HVR2), atDNA and the advanced Single Nucleotide Polymorphism (SNPs) related to my Y-DNA.
On my atDNA, I am 93% European with a little Middle Eastern thrown in.
There is an African American Carpenter line in Los Angeles that matches Group 3 of the
Carpenter Cousins Y-DNA Project. Group 3 is a Carpenter line that descends from William
Carpenter the 1638 immigrant who settled in Rehoboth, MA. Their ancestry extends to a
Carpenter who once owned slaves and who set them free in the early 1800s. Are there other
mixed ethnic Carpenter groups out there?
Yes, and some are totally unaware until they test their atDNA. But please remember that
that type of DNA test only shows fairly recent ancestry within the last couple of hundreds
of years. It does not show deep ancestry or the time before any genealogy records which is
measured in the thousands and tens of thousands of years.
FTDNA will show that you IF have some common markers with archeological DNA finds. But the
details are hidden and are for real general purposes to say ... oh, wow! I am somehow
related.
BTW – Ancestry is notorious for a low level of responses regarding atDNA matches and
communication between family trees. The provide the means but they do not promote it or
encourage it in any way. Their current TV Ads here in the States focus only on the ethnic
origins and not on how people are related. Their print Ads do have more relationship or
genealogy advertising. See the atDNA comparison link under A) below.
As a side note - FTDNA is far from perfect, but it does have a significantly higher
response rate from its users. And due to advertising and sales more people are jumping on
the FTDNA atDNA bandwagon. And their atDNA response rate will drop for the same reasons
that follow.
The far majority of Ancestry DNA test (atDNA) users have not done any genealogy. Sad, but
so very true.
And those who have done some genealogy are focused on pedigree genealogy. Pedigree
genealogy is simply filling in the blank spots on the pedigree chart not adding new cousin
lines of descent.
Being able to compare cousin genealogy, not just common surnames, is critical to atDNA
matching. Otherwise you can not triangulate the genetic data and the paper trails. See B)
below.
Genetic genealogy, in general, without the genealogical paper trails is pretty useless.
Coopers and Covingtons mainly entered the American Colonies via the Virginias. Then they
spread outward along the present day southern American states.
My paternal ancestry is primarily from the Northeastern American States then the majority
spread westwards along the northern tier of states. My maternal ancestry is German and
Austrian.
Attached is my fathers pedigree line that will show some of the surnames that I have.
(note: Rootsweb members will not see the attachment)
BTW – I am 5734 in Group 3 of the Carpenter Cousins Y-DNA Project. You can see how I
relate to Group 3 on the lineage page. See:
http://carpentercousins.com/generallineage.htm#reho – then you may need to scroll right
to see 5734. Note the blue text reflect mutations to the Group mean.
I hope this helps!
John R. Carpenter
La Mesa, CA USA
Carpenter Cousins Project
http://carpentercousins.com
A)
There are different types of DNA tests. And some companies only do one type of test while
companies like FTDNA offer many types of tests.
Y-DNA Tests
As you know the Y Chromosome is passed from father to son virtually unchanged over the
generations. This makes it ideal for surname testing.
When looking at a genealogical pedigree chart, the very top lineage is the paternal line
and represents Y-DNA heritage. This is the father’s father’s line.
Many companies used to have Y-DNA tests, but now only a few provide it. See comparison
chart link below. And these companies test some but not all of the same DYS markers. And
a few use different values (numbers) for the same DYS marker. Knowing when the test was
done and by whom will allow us to convert the values into a standard format.
Y-DNA tests come in different sizes like 12, 25, 37, 67, 111. Generally speaking the more
markers the higher the resolution or more markers to compare to. In general, one should
consider 37 markers as the starting level.
See:
http://isogg.org/wiki/Y-DNA_testing_comparison_chart
Mitochondrial DNA tests
Mitochondrial DNA (mtDNA) is passed from the mother to her children, but only her
daughters can pass it down to the next generation. Like Y-DNA this type of DNA is passed
down virtually unchanged over the generations.
When looking at a genealogical pedigree chart, the very bottom lineage is the maternal
line and represents mtDNA heritage. This is your mothers mothers DNA. Traditionally the
female assumes a married name each generation which makes it harder to track
genealogically.
MtDNA is tested in Hyper Variable Regions often called HVR1, HVR2 & HVR3. A complete
mtDNA test is referred to as mtFull at FTDNA.
See comparison chart at:
http://isogg.org/wiki/MtDNA_testing_comparison_chart
Autosomal DNA Tests
Ancestry and 23andMe focus on autosomal DNA (atDNA) FTDNA has a similar test called
Family Finder. Most people use these tests to see their ethnic heritages. So much
European, so much Middle Eastern, et cetera.
23andMe also uses atDNA type testing for medical genetic warning type tests as for Cystic
Fibrosis, Sickle Cell Anemia, Hereditary Hearing Loss and et cetera.
Some use it to compare DNA fragments to others for cousin similarity up to about 5
generations.
On a genealogical pedigree chart atDNA represents all your ancestry. You share 50% of your
DNA from each parent, 25% from each grandparent, then 12.5% by the next generation
followed by 6.25%, 3.125%, 1.5625% and further divided numbers back into time.
If you are surnamed Carpenter, any cousin match most likely will not be a Carpenter, but
from one of your other ancestors. For example, at 5 generations the likely cousin match
will be a Carpenter is 1/16 (one sixteenth),
To see the differences between these atDNA testing companies, please go to the following
link.
http://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart
SNP Tests – Big Y
Single nucleotide polymorphism (SNP pronounced Snip) testing is a shotgun approach toward
the Y-Chromosome. Most Y-DNA tests can estimate the basic haplogroup. SNP testing
confirms the haplotyping of the Haplogroup. FTDNA calls theirs The Big Y. See the link for
comparisons between the different companies who provide this type test.
http://isogg.org/wiki/Y-DNA_SNP_testing_chart
Are there other types of DNA tests? Yes. But the ones above are the most common ones used
in genealogy.
B)
Triangulation – a goal of genetic genealogy
In genetic genealogy we use triangulation. Think of a triangle. Genetic triangulation is
rather simple. /_\
Person A & B match genetically and that forms the base of the triangle. _
Person A has a paper trail (genealogy) that goes back in time. /
Person B has a paper trail that goes back in time. \
The top of the triangle is the MRCA or most recent common ancestor.
Person A is who you are testing. Some living biological male 2nd, 3rd or better cousin
could be Person B. The most common shared ancestor is the MRCA.
If the genetics of Person A & Person B match and the paper trail goes to the MRCA,
then this helps prove they are related both genealogically and genetically. This is the
goal of genetic genealogy. When this is repeated several times back to a common ancestor,
we then can recreate the Y-DNA markers of that ancestor. All without digging them up!
See more at:
http://isogg.org/wiki/Triangulation
For many groups they have a recognizable common ancestor. For Group 2 (of the Carpenter
Cousins Y-DNA Project) it is the immigrant William Carpenter b. abt 1610 in England. With
triangulation we have re-created his genetic profile or fingerprint. The same goes for
Group 3 and a few other groups.