Sinclair DNA - Mutation Rates
Click any one of these to learn about our family's complete path through time
My way around this is simply to treat our five lineages as distinct families and trace them accordingly.
This from Dr. Charles F. Kerchner, Jr.’s
site. - “Mutation Rate: The rate at which a genetic marker
mutates or changes over time... A typical mutation rate quoted in early
(circa 2001/2002) Y chromosome STR (Y-STR) TMRCA calculations and
analysis is one per 500 generations (transmission events). That would
be an average mutation rate (Y-STR Genetic Clock Mutation/Tick Rate) of
.002 or 0.2% per generation. Some commercial DNA testing labs are using
an average Y-STR mutation rate of .003 or 0.3% per generation. And a
2004 study by FamilyTreeDNA indicates that the average mutation rate
for all Y-STR markers for the male population as a whole may be twice
as fast as the historical standard rate, i.e., .004 or 0.4% instead of
.002 or 0.2%.”
But don’t get your hopes up. That basically means that now,
instead of the average mutation happening once every 500 generations,
it’s now once every 250 generations. The accepted duration of a
generation is 25 years. So, even if you’re lucky, a genetic
distance of 1 could mean you don’t share a common ancestor for
6,250 years. Of course, in our own project we know this isn’t
correct and the DNA experts aren’t saying we should hold to this
as a rule. As most say, any marker can mutate at any time. You could
have several mutating.
In his own family project, Kerchner found that his family’s
mutation rate is about once every 4.7 generations. “This is well,
well within the time frame of when surnames were adopted and well, well
within the time frame when the American colonies were settled, so one
would not expect to see any random matches with different surnames. And
in my Kerchner project I don't see any random matches at 37 markers to
people with other surnames in the FTDNA database.”
In our Sinclair project, the result is different. We do see some
non-surname matches in our 37 marker results, but not in all the
groupings or lineages. In the AMH group, we have some curious names,
but I am certain these are non-paternity events (adoptions or
otherwise) and not rapid mutation rates.
Because I know of at least one individual who will argue the case of
abnormally faster mutation rates, I’m going to quote
Kerchner’s analysis of the 25-marker test verbatim –
“For my Kerchner Surname Project the 25 marker average haplotype mutation rate for ten people YDNA25 tested is .0042.
.0042 x 25 DYS STR markers = .105 per transmission event (birth
of new Kerchner generation). (1/.105)=9.5. Thus the longevity of
the 25 marker Kerchner haplotype on average can typically survive
unchanged about 9,5 generations (transmission events). This is well
within the time frame of when surnames were adopted so one would expect
to see few if any random matches with different surnames. And in my
Kerchner project I don't have any random matches at 25 markers to other
surnames in the FTDNA database.”
Thus, he’s saying that a genetic distance of 1 equals 2,375 years.
Kerchner goes on to say, “it is becoming increasingly important
for surname project administrators to try to estimate the average Y-STR
marker mutation rate and Y-STR haplotype mutation rates for the male
line they are studying.”
”Someone asked me once. How do you do this if you don't know the
MRCA ancestor for all your surname project members but your gut
instinct and the traditional evidence and the similar haplotypes and
surnames tells you that they are all probably related in the last
several hundred years? Well if you don't know the ultimate common male
ancestor and the ancestral haplotype you cannot do it directly.”
At Least Two of our Lineages Know Their MRCA
If you know your MRCA, and your DNA shows mutations, then this becomes important for the DNA study. Suddenly we can begin to learn more. Here are two. Stan and myself show mutations on 3 markers. FTDNA throws one of these out as it's now considered a super fast mutating marker (I think it's 464b). They say we have a genetic distance of 2.
Niven and Ian Clennel are showing a distance of 3. They believe their MRCA is back in the 1400s. Now, this is not fully backed up by documents research as Ian is somewhat stuck in the early 1600s. However, there is a family story that points back to he 1400s and we have the DNA connection which is quite close.
allele | 385b | 459a | 464c |
Niven | 13 | 9 | 16 |
Ian | 14 | 10 | 17 |
allele | 439 | 464a | 464b |
Steve | 11 | 16 | 17 |
Stan | 12 | 15 | 16 |
Before I made this chart, it had occurred to me that these two lineages might be mutating on the same alleles and that others in our family might be doing this as well. I had thought I might find that our family does indeed have certain alleles that are mutating much faster than the norm, but this doesn't appear to be what's happening.
The Case for Upgrading to the 67-Marker Test
Terry Barton of World Families was chatting with me one night, helping me solve a difficult question, and mentioned that, in choosing the alleles for the 67-marker test, FTDNA had selected a set of markers known to mutate at a particularly slow rate. For this reason, those who may think they're not well matched on the 25-marker test may find they line up very nicely on the 67. So while you could be matching only 20/25 with one of our Sinclair lineages on the 25-marker test, you may find you match 62/67 on the higher order test. That would be a significant match and would likely prove a MRCA within a timeframe of genealogical interest.
Welcome to Our Main Issue
We know for a fact that we have at least 5
lineages – Our Sinclair AMH Lineage is an average genetic
distance of 8 from the S21 U106 Lineage. Even being generous, that
distance means we don’t share a MRCA until back to the accepted MRCA of 3,900 years ago. So we will explore each lineage
Another suggestion by Kerchner is actually a method I invented for our
project several years ago. He says, “...likewise one could put
together a Y-STR marker haplotype set of 12 markers which mutated on
average slower than the 12 marker panel offered by
FamilyTreeDNA.” This is very close to what I did in my “Mutation Rate
Study,” the chart with the yellow vertical lines on it that only
looked at slower mutating markers (on the results page, behind the password). This one maintained our exact
lineages with one exception and proved that we really are distinct
lineages.
A Major Goal of the Sinclair DNA Project – Determining Our Mutation Rate
In the months ahead, I’ll be actively attempting to determine
mutation rates within each of our known lineages. This will be done by
verifying where possible the MCRA for each lineage or at least among
those with a known MRCA like Stan and myself.
Sources – Website – “An Overview and Discussion of
Various DNA Mutation Rates and DNA Haplotype Mutation Rates. Do the
YSTR Haplotypes in some Y Chromosome Male Lines Mutate Faster Than in
Other Male Lines?,” Charles F. Kerchner, Jr., P.E. (Retired)
Written: 7 Jan 2005, Last Edit/Update: 17 Apr 2008,
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