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  #1  
Old 8th February 2013, 10:35 PM
Wilma Wildcat Wilma Wildcat is offline
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Haplogroup - H16-T152C! (exclamation point not mine)

Pardon me if this is a stupid question, but I used to be plain H16 -- what's the designation after that now, especially the exclamation point? Thanks in advance.
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  #2  
Old 8th February 2013, 10:44 PM
prairielad prairielad is offline
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I have a similar assignment on a FMS. My Kits Haplogroup is displayed as T2b-T152C!

I am assuming it means that marker is missing..but may be wrong
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  #3  
Old 8th February 2013, 11:12 PM
prairielad prairielad is offline
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I did find this on James Lick's FAQ page, in which I ran the analyzes on my kit and it came back as the following

Best mtDNA Haplogroup Matches:

1) T2b(T152C)

Defining Markers for haplogroup T2b(T152C):



What does it mean when a marker is in parentheses?

A. Markers which are listed in your results in parentheses are markers which are considered non-phylogenetic. Basically that means that those markers occur too frequently or change too frequently to be relevant to determining ancestry. These are treated as optional by mthap and do not contribute to scoring.

Markers which are listed in the haplogroup defining markers in parentheses are those marked as optional in the reference chart. This happens when the known sequences are too limited to be completely confident where the marker occurs, or where the marker frequently reverts back to the reference sequence value. These are also considered to be optional and are not scored


Hopefully someone that knows will clarify FTDNA assignment -T152C
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  #4  
Old 9th February 2013, 03:50 AM
Everwaiting Everwaiting is offline
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My understanding is that an exclamation point indicates a 'back mutation' in which a certain mutation that is expected within a main haplogroup is NOT present. The mutation has presumably reverted back to the early ancestral (original) state and the allele at that position matches the reference sample.
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  #5  
Old 9th February 2013, 04:30 AM
Bartot Bartot is offline
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I have seen
H2c1 - C152T!!

double !! by behar
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  #6  
Old 9th February 2013, 04:37 AM
Lklundin Lklundin is offline
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Quote:
Originally Posted by Everwaiting View Post
My understanding is that an exclamation point indicates a 'back mutation'
Yes. At phylotree.org one or two exclamation marks are used like this:

"Back mutations to an ancestral state are indicated with an exclamation mark (!), two exclamation marks for a double back mutation (!!), etc."

If on a given location (e.g. 152) you have the same value as mitocrondrial Eve, then you either had no mutations on that location, or you had an even number of mutations on that location. Looking at that location alone, there is no way to tell if you had zero, two or 10 mutations.

Similarly, if you on that location have a different value (e.g. the transition T -> C on location 152, written in shorthand as T152C or just 152C), there is no way to tell if you had one, three or any other odd number of transitions on that location.

A computer scientist could express this as: Of the number of mutations on a given location only the least significant bit can be observed.

A mathematician could express this as: Of the number of mutations on a given location only the modulo-two can be observed.

However, by looking at all of your mtDNA, one can place you in a haplogroup, with a known set of (modulo-two) mutations.

This can help distinguish between f.ex. zero or two mutations on a given location.

Let's say that your mtDNA almost perfectly matches a given haplogroup, e.g. T2b. In fact, the only thing missing in the perfect match is a mutation that defines haplogroup T.

So, there are two explanations for this difference in the match:
A) You don't belong to haplogroup T2b, in fact you don't belong to haplogroup T at all. Instead you are the single known person to belong to an as yet unseen and therefore extreme rare, new haplogroup. Or
B) You do belong to haplogroup T2b, but you have an additional mutation, that cancelled out the one that defined haplogroup T. This is a back mutation.

By choosing the least sensational explanation for the observations (this principle is called Occam's razor) you are thus assumed to fall into category B.

Subsequent mtDNA-testing may uncover additional subclades to yours. One of those could again have the mutation that you do not have (compared to mitochondrial Eve). This would thus be a double back mutation, and on phylotree.org this would be marked with two exclamation marks.
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  #7  
Old 21st February 2013, 11:50 AM
Wilma Wildcat Wilma Wildcat is offline
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Oh, ok; thanks. I'll stay tuned, then.

So if someone has a back mutation, doesn't that kind of muddy up the time to most recent common ancestor? i.e., it looks like the time is shorter than it actually took...
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  #8  
Old 13th May 2013, 06:19 PM
Wilma Wildcat Wilma Wildcat is offline
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In the continuing saga -- I just checked the mitDNA project I'm in, and they now have me the single person in my own new group: H16d

I googled it, and apparently it was "New in Build 15 (30 Sep 2012)": http://www.phylotree.org/what_is_new.htm
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  #9  
Old 10th April 2017, 05:47 PM
kilvurra kilvurra is offline
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Haplogroup - H16-T152C! (exclamation point not mine)

I'd just like to mention that I have the same exact situation as prairielad for my top match:

Best mtDNA Haplogroup Matches:

1) T2b(T152C)

My second match is T2b. I just upgraded from mtplus to FMS. My haplogroup came back as T2b-T16296C!
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