A SNP (Single Nucleotide
Polymorphism) test confirms a haplogroup designation by determining if a SNP has mutated from its derived or ancestral state.
The following cases illustrate various uses for SNP testing.
The most important aspect of all, SNP tests serve to refine a persons' genetic
signature by putting him/her within a selective group with others who are
similarly tested and found to be positive for the same marker(s). In
my case for example, at 12 markers, I was "estimated" by FTDNA
as E3b. After 25, then 37 markers tested, I was still estimated as E3b and
possibly E3b1, based entirely upon how close my genotype appeared to those
whose SNPs had been established formally. It took the SNP test itself to
prove the point. I then fell into my own little cluster, forever
identified with some but not all the other E3bers.
So why is that so important? For one thing, it narrows the array of
persons against which I need to compare myself. I can ignore anyone who is
not SNP positive the same way for I am. As to those whose SNPs are
different from mine, there is virtually no chance we are related within
multiple thousands of years. I can also exclude those who appear related
because of convergence - the random change in one or more STR
markers - because they too are not related. In other words, even if SNPs
can't tell me precisely who I am, they surely inform me who I am not.
For another thing, I can better understand the likely origin and movement
of people (tribes?) in my ancient "Y" history. Here is what the
SNPs I've tested positive for tell me about their age:
this means is that I am positive for M168, M96, P2 and 391p, M35, M78, and
time I tested positive for a SNP, the calculated timeline to its origin
brought me closer to recorded history. The last SNP in this group was V13
and the best estimate is that it arose about 11.5 kbp. The next mutation
will probably bring me to the late bronze, early iron age. Moreover, the
collectively shared view among those researching my haplogroup is that the
geographical origin of V13 is the present day Balkans. This means
that my ancestors almost assuredly were there around 9,500 B.C. from which
they moved in a westerly direction, ultimately arriving in Portugal. I
have a paper trail tracking my Y chromosome to the 1670's in northern
Portugal and two surnames (Silva and Affonso) that were within this area
at least since the 11th century.
everyone would find all this interesting or relevant to their genealogical
viewpoint, but I do. Not everyone would agree these time and location
estimates are accurate, but my response would be they are as good as the
scientific community can offer at this point and that's not bad given
there are precious few other options available. So
that, in brief and sum, is why I think SNP tests are worth the money.
- Contributed by A. Silva
NW Irish Modal
The McCabe Surname DNA study,
contains haplogroup results most of which are identified as R1b1. A
participant recently had the follow-up tests (specific SNP) provided by
FTDNA and found that he was R1b1c7, which (1) means that those who
match him are also in R1b1c7 and (2) indicates
that their roots are specifically in the area of northwestern Ireland,
Ulster and in lowland Scotland.
This is the
haplogroup of the descendants of Niall of the Nine Hostages, Niall
Noigiallach, the hypothesized High King of Ireland in the Fourth-Fifth
Century and ancestor of the Uí Néill dynasties. This
result makes the story "come alive" for those three McCabes who
have this specific sub-grouping of the R1b haplogroup. This result, as
indicated above, provides tremendous help in pin-pointing the ancestry of
those who match the R1b1c7 haplogroup.
- Contributed by James M. Freed
- Administrator for the McCabe DNA Project
A couple of years ago there was a cluster of several dozen people who tested positive for M201, so they were within Haplogroup G, but they were found to be negative for every SNP within G that was then being offered commercially. Finally, a few members of this group were tested in a small research study for what was thought to be an extremely rare
SNP, M377, defining Haplogroup G5, which had only been observed previously in two Pakistani men. Now the European branch of this haplogroup have something that clearly unifies them and adds to their sense of identity. Essentially all of this group are Ashkenazi Jews from Eastern Europe, though some did not previously know their origin.
- Contributed by Whit Athey
In the Talley project we had 3-4 people whose SNP couldn't be determined
without doing the test. This helped us determine if those with no
haplogroup predictions were related, even remotely or not. It also showed
us there would be a new haplogroup for the surname. SNP
confirmation is the top level for
division. Although rare, it indicates when there is a matching haplotype
that isn't related, but happened to mutate into the same set of marker
results. This is known as convergence.
- Contributed by Emily Aulicino -
Administrator for the Talley DNA Project
As a Newbie, I am still learning the relevance of SNP testing to my
overall genealogy and genetic ancestry.
I have just paid for FTDNA to upgrade the SNP
tests for my dad, a gt uncle (within one of my maternal one name studies -
with a rare name) and a very distant cousin (now deceased) on the same
rare name. The results in so far are fascinating...albeit I am struggling
to really put the results in perspective. The tests in our money
were very expensive but I felt that by having them refined adds a
'completeness' to the family DNA file. It allows me to continue reading
the deep DNA ancestry books coming out with a sense of involvement and
satisfies somewhat a sense of curiosity when I see so many ancestry /
history related TV documentaries regarding even the last 1-2,000 years
that we get especially from the UK. I understand SNP is relevant to
millennia ago, but somehow it helps me perhaps think where my origins
might have tracked until recent history (such as Celt / Roman /
Scandinavian migration) .....maybe such a belief is unfounded.
In summary, a rare SNP as it now appears my mother and her paternal
ancestry has tied into a rare surname, which is cause for a fascinating
but difficult genealogical task. Compared to my own which is simply the
most common UK / European yet is no less fascinating if it can be related
to an understanding of life and survival in those (possibly tribal
If the SNP goes back so far, how has the migration of my deep ancestry
changed my genetic / physical attributes to become what I am today...fair
skin, preference for cooler climes, hair / eyesight, these are some of my
curiosities and a SNP might be a clue...maybe.
- Contributed by Peter Simpson
A few years ago a false report of a "Haplogroup," issued by
another company, led two major US newspapers to report that an
accountant from Florida was a genetic descendent of Genghis Khan. Family Tree DNA subsequently tested his SNP and we proved that
he was, in fact, of a different haplogroup. After retractions by
both newspapers we launched our SNP assurance program. http://www.familytreedna.com/SNP_assurance.html which
guarantees correct placement in the phylogenetic tree through SNP testing.
- Contributed by Bennett Greenspan -
President, Family Tree DNA
the Paper Trail
A member of one of my surname projects is African American, but he was
predicted by the testing company to be in Haplogroup I1b, which suggests
that his paternal line came from Europe, rather than Africa. The
participant had traced his ancestry through traditional research back to a
slave who lived in the mid-1800s, and he wondered if the slave might have
been the son of one of the family who owned him. However, a descendant of
the owner’s family in the project did not match his STR profile. SNP
testing was ordered and the participant was found to be in Haplogroup B,
which is found almost exclusively in sub-Saharan Africa. Now the
participant knows the real origin of his paternal line.
Contributed by Whit Athey
Many thanks and appreciation to the contributors of this compilation!
All Rights Reserved
Compiled on: 01/16/2008