Go Back   Family Tree DNA Forums > Maternal Lineages (mtDNA) > mtDNA - Genealogy Basics

mtDNA - Genealogy Basics All may view this forum, but you must register and sign in to post.

Reply
 
Thread Tools Display Modes
  #11  
Old 25th October 2017, 01:16 PM
Steph Steph is offline
FTDNA Customer
 
Join Date: Feb 2017
Posts: 2
I did mtDNA because I was just interested in my haplogroup (and my father's) and believe that more information about ancient migrations will be increasingly known and by being tested I can participate in this and also benefit as the information grows. I think it's fascinating to see the links to a variety of people.

Granted, so far this is more through my dad's test, since my own has very few matches, like yours. I do have a brick wall in my maternal line and think it's possible that working with my matches (who end up in the same area and could be more closely related -- one is also a distant cousin (5th or more distant) I would have overlooked as a match without the mtDNA connection) could help me break that wall.

But another unexpected benefit is that my dad's maternal line was traced back pretty far and I was able to add more confidence in my own research by seeing that others traced back to the same woman in some cases through very different paths. But that we ended up on the same place and, yes, he and they have the same mtDNA indicates that we are on the right track, as it is unlikely that would be coincidence.

So I'm glad I did it and selfishly wish more would, but I am also just a DNA geek these days!
Reply With Quote
  #12  
Old 26th October 2017, 10:55 AM
KATM KATM is offline
mtDNA: K1a3 | Y-DNA: R-L1308*
 
Join Date: Nov 2012
Location: Mid-Atlantic coast, U.S.A.
Posts: 954
Germanica, may I ask where you found that attachment with the Full Mitochondrial chart that you posted in message #2 of this thread?
Reply With Quote
  #13  
Old 28th October 2017, 11:52 AM
Germanica Germanica is offline
FTDNA Customer
 
Join Date: Apr 2014
Location: Colorado (PA at heart)
Posts: 331
Quote:
Originally Posted by KATM View Post
Germanica, may I ask where you found that attachment with the Full Mitochondrial chart that you posted in message #2 of this thread?
It's from a pdf FTDNA put out a while ago, I don't think it's still available from them but it's still on ISOGG:

https://isogg.org/w/images/d/dd/Tr_m...ll_%281%29.pdf
Reply With Quote
  #14  
Old 28th October 2017, 03:14 PM
KATM KATM is offline
mtDNA: K1a3 | Y-DNA: R-L1308*
 
Join Date: Nov 2012
Location: Mid-Atlantic coast, U.S.A.
Posts: 954
Quote:
Originally Posted by Germanica View Post
It's from a pdf FTDNA put out a while ago, I don't think it's still available from them but it's still on ISOGG:

https://isogg.org/w/images/d/dd/Tr_m...ll_%281%29.pdf
Interesting! I found that I had saved this same .pdf from the accounts of two out of three kits that I manage, that have had mtDNAFullSequence tests done. One was completed in Jan. 2012, the other Mar. 2013. The .pdfs downloaded at those times were both named "tr_mtDNAFull.pdf," and are the same document as seen at the link you posted (there it is named "TR_mtDNAFull_(1)").

The third kit's FullSequence results were from Jan. 2016, and had been upgraded from the mtDNAPlus test, done in Dec. 2013. For the mtDNAPlus test, I had saved a .pdf at the time, titled "Understanding your mtDNA results.pdf," which used page titles of "Understanding Your mtDNA HVR1& HVR2 Results."

As this kit had been updated to FullSequence since then, I logged in and checked to see if there was a new .pdf that I had overlooked. There was, and although the link is labeled "Understanding Your Results," the actual .pdf is titled "tr_mtDNAFull.pdf," with the page titles of "Understanding Your mtDNA Full Sequence Results." BUT - comparing the two .pdfs for this kit (one for Plus, one for Full), they look very much alike, with just a bit more information in the text about the FullSequence. The new "tr_mtDNAFull.pdf," as seen in the third account, no longer includes the chart portion seen in the first and second account's mtDNA .pdfs, but has the "orange" chart also found in the Learning Center. Obviously, this .pdf has been changed; you can compare it with the chart you excerpted from the chart in the linked ISOGG .pdf.

I only go into elaborate ecstasies about this because the chart in the older .pdfs, and also still shown at your ISOGG link, shows an added column for the "differences between results," or genetic distance, for 0, 1, 2 and 3. It also has an added 75% probability column, and shows a 90% vs. the current 95% probability column. In other words, it shows more information than what is available in the current .pdf for mtDNAFullSequence.

Nonetheless, there is valuable information in both versions, the current .pdf explaining a lot about the mtDNA test results, giving resource links and a glossary of terms, plus "Quick Steps" on how to use the mtDNA section in your account. It certainly would be beneficial to people to download these documents (and Y-DNA has its equivalent) when they get their results, and studying them. Surely fewer questions might be asked in the FTDNA mtDNA subforums if they did!

Last edited by KATM; 28th October 2017 at 03:16 PM.
Reply With Quote
  #15  
Old 28th October 2017, 05:08 PM
Germanica Germanica is offline
FTDNA Customer
 
Join Date: Apr 2014
Location: Colorado (PA at heart)
Posts: 331
Yeah, I don't know why they stopped including the genetic distance chart - people are always asking what the genetic distance means and that orange chart doesn't help with that. They still have a genetic distance chart for Y-DNA, so why they removed the one for mtDNA is not something I understand and I'm just glad the original one is still available at ISOGG.
Reply With Quote
  #16  
Old 29th October 2017, 12:45 AM
dna dna is offline
FTDNA Customer
 
Join Date: Aug 2014
Posts: 2,673
Quote:
Originally Posted by Germanica View Post
Yeah, I don't know why they stopped including the genetic distance chart - people are always asking what the genetic distance means and that orange chart doesn't help with that. They still have a genetic distance chart for Y-DNA, so why they removed the one for mtDNA is not something I understand and I'm just glad the original one is still available at ISOGG.
I am guessing that evolutionary convergence ( https://isogg.org/wiki/Convergence ) could be the reason FTDNA does not include the mtDNA chart anymore.

Mr. W

P.S.
Among my family members who tested at FTDNA, there are two whose mtDNA haplogroup is H. They have hundreds of matches, and if the table was valid there should be at least some from the same region in Europe. And there are none. I know, the sample size is small, but I am convinced that my guess goes in the right direction.

Last edited by dna; 29th October 2017 at 12:49 AM.
Reply With Quote
  #17  
Old 29th October 2017, 11:57 AM
Germanica Germanica is offline
FTDNA Customer
 
Join Date: Apr 2014
Location: Colorado (PA at heart)
Posts: 331
Quote:
Originally Posted by dna View Post
I am guessing that evolutionary convergence ( https://isogg.org/wiki/Convergence ) could be the reason FTDNA does not include the mtDNA chart anymore.
But then why have genetic distance to begin with? Why use genetic distance, but fail to explain what it is with the chart? If the issue is that genetic distance can be misleading or incorrect, wouldn't it be better to just not use it at all, rather that use it but not tell people how to understand it?

And wouldn't this apply to Y-DNA too? So why have the chart for Y genetic distance, but not mtDNA?

In autosomal DNA, you can also have endogamy which can fool you into thinking a match is a closer cousin than they are but they doesn't stop companies from estimating the relationship degree.
Reply With Quote
  #18  
Old 29th October 2017, 06:10 PM
dna dna is offline
FTDNA Customer
 
Join Date: Aug 2014
Posts: 2,673
Quote:
Originally Posted by Germanica View Post
But then why have genetic distance to begin with? Why use genetic distance, but fail to explain what it is with the chart? If the issue is that genetic distance can be misleading or incorrect, wouldn't it be better to just not use it at all, rather that use it but not tell people how to understand it?

And wouldn't this apply to Y-DNA too? So why have the chart for Y genetic distance, but not mtDNA?

In autosomal DNA, you can also have endogamy which can fool you into thinking a match is a closer cousin than they are but they doesn't stop companies from estimating the relationship degree.
I think most of the confusion is due to the following two factors:
* DNA analysis is non-trivial;
* DNA science keeps evolving at a rapid pace.

Genetic genealogy started being very simple, and genetic distance combined with probabilities of relationship is an easy to understand concept, both for mtDNA and Y DNA.

Not only that originally nobody knew that evolutionary convergence plays such a big role when comparing mtDNA lineages, but there were just not enough people who tested their entire mtDNA to see the issue.

The same with Y DNA, although availability of the Y-DNA111 test makes it less of a problem. Also a SNP test can help in deciding whether it makes sense to use STRs for a relationship calculation. That is probably why Genetic Distance stayed with Y DNA results despite evolutionary convergence clearly happening in the Y DNA realm ( https://isogg.org/wiki/Convergence ).

You are right, endogamy increases uncertainty margins, but how many of us would like to see a statement that there is 90% chance that the relationship is 4th-5th cousin, and that the 90% estimate is valid in 97% of cases. (The above numbers are entirely bogus, I have no idea what the actual number ranges could be.)

Even today, people just grab the first number they see, say a 91% probability of a relationship within 16 generations, and ignore the remaining percentage (9%).

Or how many people just say what?!? upon reading reading
Are there any exceptions or special cases in how our DNA is inherited that would affect my predicted relationship and range?
https://www.familytreedna.com/learn/autosomal-ancestry/universal-dna-matching/exceptions-special-cases-inherited-affect-shared-dna/



On the fundamental level, genetic distance (mtDNA & Y DNA STRs) and predicted relationship level (Family Finder) are probably just fine. It does not appear that there is an increasing percentage of people who have unusual results that require advanced analysis. It appears that there are much more testers, so the count of individuals with with unusual results (that require advanced analysis) keeps increasing.


Mr. W

P.S.
The above is me guessing FTDNA thinking... With the Big Y test, FTDNA clearly wanted to move away from offering interpretation of the results, so I guess my guess has some merit :-)

Last edited by dna; 29th October 2017 at 06:18 PM.
Reply With Quote
  #19  
Old 1st November 2017, 11:39 PM
GST GST is offline
FTDNA Customer
 
Join Date: Oct 2005
Posts: 512
Quote:
Originally Posted by Germanica View Post
Yeah, I don't know why they stopped including the genetic distance chart - people are always asking what the genetic distance means and that orange chart doesn't help with that. They still have a genetic distance chart for Y-DNA, so why they removed the one for mtDNA is not something I understand and I'm just glad the original one is still available at ISOGG.
The genetic distance chart is not accurate - on average, the number of generations should be increased by about a factor of 10, but average genetic distances are not very meaningful for evaluating mtDNA matches. So it would be best to delete the chart and explain how to evaluate matches.

mtDNA has a very slow mutation rate, on average about 1 mutation in 3000 years, but it is also highly variable. Some people can have several mutations in 3000 years and their matches will be much more recently related; other people have had no mutations in their maternal line in over 10,000 years and their matches can be very distantly related.

There is also a problem that FTDNA counts some mutation hot spots and heteroplasmies in the genetic distance, and people who are very closely related on the maternal line are sometimes shown with a genetic distance of 1, 2 or more. So you really need to compare the detailed results to see what mutations are being counted in the genetic distance.

I've been posting this information for years - I wish we could get FTDNA to provide a better explanation for mtDNA matches. mtDNA matches can be useful for genealogy in some cases but only if people understand how to interpret the results.

Regarding genetic convergence - this is an issue for STR matches in y-DNA, not for mtDNA.

Last edited by GST; 1st November 2017 at 11:45 PM.
Reply With Quote
  #20  
Old 2nd November 2017, 11:51 AM
marietta marietta is offline
FTDNA Customer
 
Join Date: Feb 2013
Posts: 497
Blog Entries: 1
Gail, thank you for outlining your position with which I totally agree! I hope FTDNA is listening.

And, in the future, FTDNA should reflect more transparency/clarity in their graphics so people understand the difference in mtDna and FF testing; and will not mistakenly order mtDna testing when what they really need is FF. Your customers deserve this......

I HAVE had full sequence mtDna testing, and I am an advocate. As Gail said, it can be very helpful for genealogy. E.g., it can rule in, or rule out, Native American on the maternal line.

Last edited by marietta; 2nd November 2017 at 12:05 PM.
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
confused about my MtDNA results Fatosh19 mtDNA - Advanced Topics 0 17th October 2012 10:45 AM
Somewhat confused. drjmac DNA and Genealogy for Beginners 1 13th July 2010 02:28 AM
L2a mtDNA results...Hit a brick wall..sort of confused. RColeman The Genographic Project 1 20th June 2010 01:21 AM
Now I'm Really Confused.... nikkicivetti DNA and Genealogy for Beginners 4 21st January 2010 12:13 PM
Confused Dawn Ellis Group Administrators - Advanced Chat 4 11th November 2006 07:37 PM


All times are GMT -5. The time now is 07:52 AM.


Family Tree DNA - World Headquarters

1445 North Loop West, Suite 820
Houston, Texas 77008, USA

Phone: (713) 868-1438 | Fax: (832) 201-7147
Copyright 2001-2010 Genealogy by Genetics, Ltd.
Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.