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
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

Wednesday, September 16, 2015

Autosomal Small Segment Triangulation HAM DNA Group #1

Small Segment Triangulation
HAM Y-DNA Group #1

The main purpose of the paper was to provide instructions that will permit viewing matching autosomal shared segments when FTDNA does not provide that information. Further, the intent is to help analyze a Y-DNA Group for matching shared autosomal segments by direct comparison between three or more people. This was written for those who had problems finding autosomal matches and who were also participants in the Y-DNA project. It is meant to help with a problem when the Y-DNA indicates that you should have a match, but the autosomal DNA indicates no match.

Screenshot of Autosomal Small Segment Triangulation

See also:

"Table 5 shows a typical set of alleles... These alleles (AA and CC) may indicate a Mediterranean ethnicity. The probability of a one to one match on this segment being a false positive calculates to be 1 in 7 quadrillion."

"Many 7 cM matches are SNP poor and under certain conditions will calculate as a false positive. There are many triangulated matches at 2.5 cM that confirm a relationship. Unfortunately, that relationship may be in the 7 to 14 generation range, making it difficult to determine the common ancestor. Triangulated small segment matching is very valuable in our research."
The process of genetic inheritance is often over simplified, leading consumers of genetic tests to believe that the amount of DNA from distant ancestors becomes negligible. In fact, segments of DNA pass down through the generations intact. Naturally occurring cleavage sites allow for small segments to exist at recurring chromosomal locations. These small segments can be used as familial markers in an autosomal haplotype.

Maximum-likelihood estimation of recent shared ancestry (ERSA)

Accurate estimation of recent shared ancestry is important for genetics, evolution, medicine, conservation biology, and forensics. Established methods estimate kinship accurately for first-degree through third-degree relatives. We demonstrate that chromosomal segments shared by two individuals due to identity by descent (IBD) provide much additional information about shared ancestry

A Study Utilizing Small Segment Matching

"Now that we understand IBS, IBD, Phasing and how matching actually works on a case by case basis, let’s look at applying those same matching and IBS vs IBD guidelines to small data segments as well."

4 Generation Inheritance Study

"There is a lot more information available to us in our DNA results than is first apparent.  It takes a bit of digging and you need to understand how autosomal DNA works in order to ferret out those secrets.  Don’t discount or ignore evidence because it’s more difficult to use – meaning small segments.  The very piece or breadcrumb you need to solve a long-standing mystery may indeed be right there waiting for you.  Learn how to use your DNA information effectively and accurately – including those small segments."

Monday, May 4, 2015

Ham, Creech St. Michael, Somerset

Ham, Creech St. Michael, Somerset

Jon Hamm has sent an email containing some local photographs of the village of Ham, near Creech St. Michael, Somerset. Jon is from East Brent, Somerset, and had previously sent pictures of St. Michael's Church in Brent Knoll, Somerset.

Lane End Inn and Ham Road, Creech St. Michael, Somerset

Creech St. Michael is in the vicinity of Taunton, and the use of the name was in use in 1244-45.

Ham Bridge, near Creech St. Michael, Somerset
Ham, near Creech St. Michael - photos courtesy of Jon Hamm, East Brent

Village of Ham, near Creech St. Michael
- photo courtesy of Jon Hamm, East Brent

View of the Tone River from the Ham bridge.

Ham Wharf, near Creech St. Michael, Somerset

Corner of Ham Road and Lane End, Somerset







Ham village Orchard - photos courtesy of Jon Hamm, East Brent, Somerset

Map of the village of Ham, near Creech St. Micghael,
Somerset circa 1900

Thanks should go out to Jon Hamm, for taking the time to photograph the Ham village.  

I chose to put these pictures together into a You Tub Video, so that I could take the time to put together a presentation of the relevance of the Ham surname in the area of Taunton.

I hope that you enjoy the video.