Go Back   Family Tree DNA Forums > Group Administrators Forums > Group Administrators - New and Begining Admins

Thread Tools Display Modes
Old 10th February 2018, 01:42 PM
jmcgill jmcgill is offline
FTDNA Customer
Join Date: Nov 2017
Posts: 9
Significance of Genetic Distance

In the McGill group we have two kits (206503 is the nephew of 126052) that have a Genetic Distance of 2, with both tested at 37.

One of the sites they differ is DYS464, which is a rapidly mutating site, indicated by it being red. The other site is DYS607 which is not considered rapidly mutating.

Is this expected? This seems to me like a big difference in one generation. I guess they could both test to Y111 or do SNP testing to see how much they really differ.
Reply With Quote
Old 11th February 2018, 06:22 AM
Jim Barrett Jim Barrett is offline
FTDNA Customer
Join Date: Apr 2003
Location: Timpson, TX
Posts: 2,153
Shouldn't you count generations from the common ancestor?

A man(A) has two sons(B & C). It is very possible they have a genetic distance of one or more. One of the brothers(B) has a son(D). Again it is very possible for them to have a genetic distance of one or more.

In your case you are comparing C to D. D is two generations from A.

A genetic distance of 2 may be more than "normal" but it isn't unusual.
Reply With Quote
Old 11th February 2018, 01:48 PM
clintonslayton76 clintonslayton76 is offline
FTDNA Customer
Join Date: Jun 2014
Posts: 217
I guess they could both test to Y111 or do SNP testing to see how much they really differ.
Spending the money to confirm an estimated difference is your choice, but as Jim Barret says, there is nothing unusual in this GD esult. The higher res STR will give a more accurate GD, but when a relationship is known, searching for a variant beyond what is already known will not really change anything, will it?

A Haplo admin might suggest a SNP pack as a less expensive alternative to upgrading to 111, but sponsoring an expansion of this lineage with other male results (when possible) seems a better use of funds, in my opinion. Then again, I might be an idiot...
Reply With Quote
Old 11th February 2018, 02:58 PM
The_Contemplator The_Contemplator is offline
FTDNA Customer
Join Date: Jun 2015
Posts: 816
Nothing states that a GD of 2 is not possible, but as noted you have to consider it from the common ancestor. But if you are still doubtful about the connection (in spite of it being known), both can take the Family Finder test. They would be very high matches to each other given the expected connection.

With closely related Y matches, you may find that the "red" STRs are more likely to be the places where they differ. The other marker could indicate a new branching point for the STR signature between one of them. I agree that funds would be better spent on a more distant cousin to these two individuals than to do additional testing for both.
Reply With Quote


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
Genetic Distance (1) ??? soft heart Y-DNA Haplogroups & SNPs Basics 2 24th October 2016 06:10 PM
what is the significance of genetic distance 2 at 12 markers y-dna? Jesse1961 Paternal Lineage (Y-DNA STR) Advanced 4 23rd September 2013 12:05 PM
Genetic Distance Help JamesBianco Paternal Lineage (Y-DNA STR) Advanced 2 28th February 2013 11:25 AM
Please Help with genetic distance Mlawton Paternal Lineage (Y-DNA STR) Advanced 2 26th February 2013 12:11 AM
genetic distance DHDH Paternal Lineage (Y-DNA STR) Advanced 20 20th June 2006 12:08 PM

All times are GMT -5. The time now is 09:04 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.