Thursday, December 28, 2017

Autosomal Small Segment Phylogenetic Tree

  Autosomal Small Segment Phylogenetic Tree

 

Small Segment Triangulation
HAM Y-DNA Group #1


Taking some inspiration from Dean McGee, I put together a phylogenetic tree of the HAM autosomal DNA, using tiny thresholds and the largest shared segments of these small segments. For this one, these are not triads, they are just the largest of the small shared segments.
 
Basically, the autosomal DNA testing companies set a low threshold,
meaning they usually do not show much beyond 5th cousins (for the
autosomal DNA). As most of you know the Y-DNA goes much further back.
For Family Tree DNA and GEDMatch the threshold is set at 7 cMs.
 
Folks in our HAM Y-DNA Group #1 upload their autosomal DNA to GEDMatch, and I have lowered the thresholds by using GEDMatch utilities. The results from the largest shared segments roughly follow the Y-DNA, except that the autosomal DNA has totally separated out the line of our William HAM, Sr. of Grayson County.
 
For this study, I was not using triads, but simply the largest shared autosomal segments. Mostly from either FTDNA or Ancestry.
 
We have enough participants from Grayson County to almost make out his
three sons (John HAM, William HAM, Jr. and Thomas HAM).
 
If you wand the mouse over the tables (following the link below), it should show the largest shared chromosome and location. For example, a wand over of the horizontal for A274xxx (Roxanne) and her largest segment for T133xxx (Mary Ann Talbott) it shows the largest shared segment to be:

Chr     Start Location      End Location   Centimorgans (cM)

12        123,996,713        130,079,716         24.2

Moving the mouse to the right for A274xxx (Roxanne) andT074xxx (Wendell
Seaborne) it shows the largest shared segment to be:

Chr      Start Location      End Location   Centimorgans (cM)

12        123,996,713        128,587,277        18.1

Which is pretty much the same segment, meaning that Roxanne, Mary Ann,
and Wendell share the same largest tiny segment from the same ancestor.
The idea is to figure out which ancestor is at that location on that
chromosome. 
 
We also see the LOVIN NPE appears to be out of the Amelia County, VA HAM line.
 
We have no Y-DNA from Amelia County, just autosomal DNA. My guess is that his ancestor died in war and he was adopted. His line is more recently from Wayne
County, NC (from about 1800), and he does not match the Y-DNA of Wayne
County HAM lines.

Also, it looks like Amelia Co. and Patrick County, VA HAM lines split off from the Somerset HAM line earlier, and the Ashe County HAM line split from the Somerset HAM line later.
 
 
Group #1 Largest Shared Matches to Small Autosomal DNA Segments with Phylogenetic Tree
 
 
 
HAM Group 1 Autosomal DNA Phylogenetic Tree
Update Jan 31, 2018:
 
The exponential Half Life decay equation for Genetic Distance in this article was updated to show the resulting Genetic Distance and phylogenetic tree. 


References:


HAM Group #1 Information

HAM Y-DNA Project Phylogenetic Tree

HAM Group #1 Initial Tiny Autosomal Segment Triad Study

HAM DNA Project Dean McGee's Utility output

HAM DNA Project Y-DNA Results at HAM Country

HAM DNA Project at FTDNA

How to Read HAM DNA Phylograms
    (video)