Go Back   Family Tree DNA Forums > Universal Lineage Testing (Autosomal DNA) > Family Finder Advanced Topics

Family Finder Advanced Topics Advanced discussion about Family Tree DNA's Family Finder Product.

Reply
 
Thread Tools Display Modes
  #1  
Old 11th November 2017, 11:02 PM
wombat wombat is offline
FTDNA Customer
 
Join Date: Apr 2015
Posts: 257
odd DNA matching

On Ancestry.com persons A and B match on a certain segment on a certain chromosome (among other places) and also match relatively recently through genealogical paper research.

On 23 my mom and I match person A on that certain segment on that certain chromosome but my dad does not. On FTDNA my dad matches person B on that certain segment on that certain chromosome but my mom and I do not.

The segment is 16-18cM long so it's not that small.

What do people make of this

(also: person A is a V5 tester, we are all V4 testers; person B is a FamilyFinder tester and my parents are Geno 2.0 NG transfers and I am a MyHeritage transfer)

Last edited by wombat; 11th November 2017 at 11:07 PM.
Reply With Quote
  #2  
Old 11th November 2017, 11:10 PM
georgian1950 georgian1950 is online now
FTDNA Customer
 
Join Date: Jun 2012
Posts: 641
Hi Wombat,

Could you give the chromosome number and locations of that segment?

Thanks,

Jack
Reply With Quote
  #3  
Old 13th November 2017, 04:33 PM
wombat wombat is offline
FTDNA Customer
 
Join Date: Apr 2015
Posts: 257
Well, I guess it was just a freak and confusing coincidence.

And B are relatively closeish cousins, something like 1/2 third cousins or something. Person A has tested only at 23andme and Ancestry and person B only at FTDNA and Ancestry.

My mom and I match person A on a certain spot on 15 on 23andme and my dad matches person B on just about the same certain spot on 15 on FTDNA and with A and B related it seemed like it had to be that we actually all matches on that same spot on 15. (It turns out that I was wrong that they knew they both matched on the same spot on 15, apparently with Ancestry the tools don't even let you know).

But then B uploaded to GEDMATCH and no matter how I dug, even at 200SNPs, 3cM I could find no match for my mom or I on that spot on 15 to person B and even overall at just 300 SNPS and 5cM is said we are not related to person B. So I guess it was just total crazy random luck that my mom and I are related to A and my dad is to B and both by even more crazy luck on nearly the same spot on 15, must be to opposite strands or that they (A and B) ended up not getting the same segment from their mutual in common ancestors.

Anyway it shows the importance of both chromosome browsers, which Ancestry apparently lacks, and being able to dial in and adjust settings and that you just can't make an leaps of assumption.

So I guess my mom and I are related to A and not B and my dad to B and not A and how we are related to them is through totally different paths. The surprising thing though is that B has a match in common who then in tern matches one whole side of my dad's matches and then another who matches on whole side of my mom's. Due to that we had been even more sure we'd end up all matching A and B on 15 the same way. But it seems something much more tangled and complicated is going on in the big puzzles we have.

It's so weird that my dad has now twice ended matching people we'd thought my mom would and then my mom not matching them at all, etc. etc.

Something confusing and complex is going on, but anyway there does not seem to be any matching issue going on at either 23 or FTDNA and freak chance no calls in the wrong spots, etc.
Reply With Quote
  #4  
Old 13th November 2017, 05:37 PM
georgian1950 georgian1950 is online now
FTDNA Customer
 
Join Date: Jun 2012
Posts: 641
wombat, was the match overlapping any of the 24.0 - 30.0 Mbp range on #15.

Thanks,

Jack
Reply With Quote
  #5  
Old 13th November 2017, 06:11 PM
wombat wombat is offline
FTDNA Customer
 
Join Date: Apr 2015
Posts: 257
Quote:
Originally Posted by georgian1950 View Post
wombat, was the match overlapping any of the 24.0 - 30.0 Mbp range on #15.

Thanks,

Jack
no, I think each of the matches is more like in roughly the 80-90 range, in fact, for my dad and person B here it is 83.9-90.8 Mbp range on #15 which it calls 16.7cM so I guess it applies a large factor to that region, GEDMATCH seems to call it 13.7cM

and even going to 200SNPs, 3cM I can't get GEDMATCH to find any match for my mom and person B on #15 anywhere even near that at all

Last edited by wombat; 13th November 2017 at 06:14 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
NON MATCHING KNOWN SNP's htb BIG Y and SNP Discovery 3 20th May 2017 12:43 AM
DNA Matching deleonjoe DNA and Genealogy for Beginners 4 27th November 2016 06:00 PM
Big Y matching vinnie BIG Y and SNP Discovery 4 5th May 2016 03:40 AM
BIG Y MATCHING fmoakes BIG Y and SNP Discovery 8 2nd September 2014 10:41 AM
Matching Wills Paternal Lineage (Y-DNA STR) Advanced 3 10th April 2013 09:24 PM


All times are GMT -5. The time now is 10:57 PM.


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 - 2017, Jelsoft Enterprises Ltd.