FREQUENTLY ASKED
QUESTIONS
1. How can I join
the Project and become a volunteer?
Either contact me by clicking on the "CONTACT US" link on the homepage,
or go directly to www.familytreedna.com. Once there, click on the
heading "Surname Project," then click on the letter "T."
Scroll down until you see the surname "Thorpe." Once you have
clicked on the appropriate surname, there will be instructions on how
to sign up for the test.
2. How are the DNA samples obtained?
All tests are non-invasive. Test kits are sent directly to the
volunteers home. Each kit contains two small vials filled with
liquid and a cheek scrapper. Using the scrapper (which looks like
a small metal toothbrush), the volunteer firmly scraps the inside of
his cheek for approximately a minute. A portion of the scrapper
is then gently injected into a vial. The test is performed a
second time after at least eight hours have elapsed. This second
test insures that the lab will receive at least one useable sample of
DNA material from the volunteer. Both vials are then placed in a
return envelop included in the test kit and sent back to the lab for
analysis. Finally, the test kit also contains a release form that
the volunteer signs in order for the results of the test to be shared
with the Project.
3. How long before the DNA results are available?
Test results are usually available 4-6 weeks after the lab receives the
test kit back.
4. What is the difference between a 12, 25 and 37 marker test?
The differences between the tests is based on the number of
Y-chromosome markers examined to determine a possible genetic match
with another line. The more markers examined, the more detailed
and certain the haplotype of the particular lineage being tested.
Thus, a 37-marker test will provide a much more accurate and detailed
haplotype analysis than a 25-marker test, and a 25-marker is much more
detailed than a 12-marker. Additionally, the time frame to the
most recent common ancestor (MRCA) is much shorter with a 37-marker
test match than a 12-marker match. Some volunteers chose to start
with a 12-marker test, then if there is a possible genetic match,
upgrade to a 25 or 37-marker test.
5. What is the cost for the tests?
The cost for a 12-marker test is $99, plus $2.00 shipping. The
cost of a 25-marker test is $169, plus shipping. Finally, the
cost of a 37-marker test is ?, plus shipping. Volunteers can
chose to pay by credit card or can be billed when the testing kit
arrives. Payment plans are also available. We don't want
the cost to be prohibitive and prevent volunteers from joining the
project who would normally like to do so. Please contact me
(Ellen Coffman, Thorpe DNA coordinator) if you think you would like to
participate, but need to work out a cost effective plan to join the
Project.
6.Why can't females or descendants of females participate in the
Project?
The Center for Genetic Anthropology at University College, London,
explains it in the following fashion: "Because the Y chromosome cannot
readily exchange any of its substance with X (the female chromosome),
the Y of each living man directly resembles that of his father, his
grandfather, great grandfather and so back in history. Analysis
of Y chromosomes is therefore potentially a very powerful way of
determining historical male lineages and the relationships between
contemporary males. That particular type of record does not hold
for females because of the interchange between the two X chromosomes of
the 23rd pair (one from the mother, the other from the father)."
Still confused? Let's review more basic genetic information for a
better understanding of what goes on within each of our bodies.
The tiny structures we know as "chromosomes" are in almost every one of
our cells. There are 23 pairs of chromosomes, one member of each
pair contributed by the father in his sperm, the other by the mother in
her egg. From the original fertilized egg, the chromosomes are
copied over and over again so that as we grow, each new cell in our
bodies has a full set. Or nearly every cell: one exception
to this are the sperm and eggs which contributed to the next generation
when we have our own children. Only one member of each pair of
chromosomes is present in sperm and egg cells, so that when the two
come together in the act of fertilization, the full set is restored and
a new combination is created.
In 22 out of 23 pairs, the two chromosomes (one originally from the
mother, the other from the father) actually interchange genetic
material between themselves, so that eventually, an individual's
chromosomes become a mixture of both maternal and paternal
lineages. But the 23 "pair," called "X" and "Y," exchange almost
no genetic bits (or so geneticists at this time believe). Women
have two X chromosomes in the 23rd pair (which do sometimes exchange
bits of information), and their eggs therefore have just one X.
Men, however, carry one X and one Y, and half their sperm are X and
half are Y. If an egg is fertized with an X sperm the resulting
individual is XX and female; if a Y sperm is involved in the
fertilization, the combination is XY and male. That's how males
and females are created from the chance mating of an egg with one or
other type of sperm.
7. So how does the female DNA testing differ from the male test?
Something to note about all this is that we all still inherit an X
chromosme (mitochondrial DNA or mtDNA for short) from our mothers, but
not from our fathers. Your mother inherited it from her mother,
who inherited it from hers, and so on back through time.
Therefore, Mitochondiral DNA traces an unbroken maternal line back
through time for generation upon generation further back than any
written record.
Research has shown that all our maternal lines are connected at some
point in the past (the mitochondrial "Eve") and that these connections
can be traced by reading MtDNA. Interestingly, this single
maternal line eventually split into approximately 33 lines (or clan
mothers as they are sometimes called) and these clans then spread out
from Africa to populate the rest of the world. Geneticists can
now determine which of these 33 clan mothers you descend from by
reading precise sequences of your mtDNA.
Because mtDNA changes at a much, much slower rate than the
Y-chromosome, everyone in the same clan has exactly the same mtDNA.
Both men and women can test their MtDNA, since both inherit their
mother's X chromosome. However, since women do not possess the
Y-chromosome and its quickly mutating DNA, they cannot be tested for
more recent genetic connections. Thus, while mtDNA testing is
ideal for determining your deep ancestral origins stretching back over
tens of thousands of years, only Y-chromosome testing can determine if
two people shared a recent (within 500 years or less) common ancestor.
8. How can you obtain the DNA of someone who lived hundreds of years
ago?
We obtain the DNA of ancestors though their living representatives:
YOU! We are, essentially, our ancestors. Basically, if you
are male, you inherit the same Y-chromosome markers as you father, who
inherited it unchanged from his father, and so on. Thus, a direct
male descendant of Thomas Thorpe of Woodbridge has the same DNA on his
Y-chromosome as Thomas himself did. The markers on the
Y-chromosome do mutate, of course, but at a relatively stable rate
(say, only a few mutations every 500 years. However, there have
been some cases where the DNA of brothers have shown mutations from
each other).
9. How many markers must match for two individuals to be considered
related?
Because we are all related at one point in time, the key element in
evaluating matches between haplotypes is the time frame. If two
people match 12/12 or 25/25 and the surname matches or is a variant,
then they are probably related since the time of the adoption of the
surname. If two people have an exact match, but the surnames are
different, they were probably related to each other before the adoption
of surnames. Since surnames began to be introduced and adopted
between 1000-700 years ago in Europe (though at differing rates at
different places), matches with other surnames is generally not
relevant to genealogical research.
The following distribution of time to the most recent common ancestor
(also known as "MRCA") is provided by geneticist Bruce Walsh and Family
Tree DNA. These are conservative estimates and are frequently
being revised as we continue to increase our knowledge of haplotype
mutation rates. Additionally, some markers have been found
recently to mutate more quickly than others, which probably affects the
time frame to the MRCA.
MATCH: 25/25: 50% probability that lines shared a MRCA within 7
Generations (175 years)
90% probability thatl lines shared a MRCA within 23 Generations
MATCH 24/25: 50% probability that lines shared a MRCA
within 17 generations (425 years)
90% probability that lines shared a MRCA within 40 generations
MATCH 23/25: 50% probability that lines shared
a MRCA within 28 generations (700 years)
90% probability that lines shared a MRCA within 56 generations
MATCH 12/12 50% probability that
lines shared a MRCA within 14 generations (350 years)
90% probability that lines shared a MRCA within 48 generations
MATCH 11/12 50% probability that
lines shared a MRCA within 37 generations (925 years)
90% probability that lines shared a MRCA within 85 generations
Note that each generation is based on a 25 year interval of time.
10. What is a haplotype?
The Y-chromosome inherited by men changes (or mutates) much more
quickly than mtDNA. Geneticists call these small changes on the
Y-chromosome polymorphisms. As DNA is copied from cell to cell
and from generation to generation, small "mistakes" or mutations occur
in the DNA chemical sequences that do not cause damage to the
offspring. These changes are then passed on to the next
generation, father to son, on the Y-chromosome. It is these
changes that we look for in DNA testing. We record the frequency
of different combinations of polymorphisms or mutations - this is your
haplotype. Using reasonable assumptions about the rates at which
different types of mutations occur, one can esitmate a date for the
most recent common ancestor between two individuals. The more
similar any two individuals haplotype's are, the more closely they are
related (i.e. the more recently they shared a common ancestor).
Note that Ychromsome DNA testing is still in its infancy. In
fact, up until a few years ago, no polymorphisms had been discovered,
and even today relatively few have been described. The same can
be said for mtDNA testing - there are relatively few studies that
investigate the 33 clan mothers that have populated the world.
Still, our understanding of the Y-chromosme and mtDNA genetics grows
daily as more studies are performed and more surname projects like the
THORPE DNA PROJECT contribute to our knowledge.
11. What is a haplogroup?
Haplogroups are defined by a different set of markers than those tested
to obtain an individual's haplotype. Like the 33 clan mothers
determined by mtDNA testing, haplogroups are based on a small group of
"founding fathers" who populated the world. The founding father
(or fathers) who had the mutation which defined a haplogroup had
a specific haplotype. His descendants will accumulate mutations
on the DNA foundation he provided, and after thousands of years, there
will be a great number of different haplotypes, but there will still be
some traces of the founding father.
For example, members of Haplogroup R1b are believed to be the
descendants of the early Paleolithic hunter-gathers of Europe.
Certain haplogroups are seen more frequently on the eastern side of
Europe, while others are more common on the western side. A
certain haplogroup has been found to be very common amongst modern day
Scandinavians, but less common amongst other European populations.
If you are a volunteer in the THORPE DNA PROJECT, not only will you
receive an analysis of your haplotype, but your haplogroup will also be
identified.
12. Will I be able to tell which area of the world my ancestor came
from by participating in the Project?
Possibly, though keep in mind that haplogroup classification is not the
most useful tool for locating the place of origin of your paternal
line. While each haplogroup has very general areas in which it
may be more common, there has been enough mixing of people on the
European continent to prevent using these classifications to identify
any single place of origin.
Haplogroups are important to genealogists because it identifies people
who share marker values with each other and therefore belong to the
same haplogroup.
PLEASE CONTACT ME IF YOU HAVE ANY FURTHER QUESTIONS THAT WERE NOT
ADDRESSED IN THE "FAQ" SECTION.