Friday, August 27, 2010

DNA and the “Process of Elimination”

This post is two-fold: It talks about how I used the process of elimination through my focus on the “other” family and how it led to my interest in using DNA to distinguish between individual kinship lines.


I have spent the last several years trying to determine who the parents of my ancestor, Elijah Godwin were.  I got it narrowed down to one couple - Nathan Godwin  and Sarah Latham of Randolph County, North Carolina with little uncertainty. 

In the course of my search I employed what I like to call the “Process of Elimination” technique whereby I study the records of all nearby same-surname families in order to eliminate them as “possible” matches.  In doing so, I came across Nathan’s brother, Etheldred Godwin (1776-1852).  Both Nathan and his brother Etheldred Godwin removed from Randolph Co., North Carolina to Putnam Co., Indiana in 1828 with their children.  However shortly after 1830, the two brothers went their separate ways  and Nathan Godwin removed again to Perry Co., Illinois where he died in 1833, however, many of his children stayed behind in Indiana.

I had to study both families in order to sort through all the Godwin descendants I came across in Illinois, Iowa and Indiana and to place them with the correct ancestor, Nathan or Etheldred.  The fact that the names Nathan and Etheldred were passed down through the generations in both families made it even more difficult to place them into their respective families. 

I was eventually able to trace all seven of Etheldred Godwin’s descendants through deed records recorded by his heirs after his death in 1852.  I wrote a series of posts highlighting this endeavor in:

 Finding the Heirs of Etheldred Godwin

Eliminating these Godwins as possible descendants of the Nathan Godwin I was interested in allowed me to focus on the Godwins who were left over as better candidates;  And to identify them as a significant relationship to my ancestor, Elijah Godwin.

The “cousins”….

While I was focusing on sorting through Etheldred Godwin’s line (which was NOT necessarily a bad thing because after all he WAS a brother of my ancestor, Nathan Godwin), I met several other researchers who were trying to place their ancestors as descendants of Etheldred Godwin

Through collaboration and the deed records I found, as I said earlier, we were able to place their ancestors as children of Etheldred Godwin.  There was one small snag, however.  One of his 7 heirs, Sarah Godwin, who sold off her 1/7th share of his land after his death, was married to her first cousin, Jonathan Godden.  It is still unclear about whether Sarah Godwin was Etheldred Godwin’s daughter or Granddaughter. At this time, however, it is not really a concern. 

The significant part of this relationship is on Sarah’s husband Jonathan Godden’s side.  According to family letters and census records, Jonathan Godden’s father was Enoch Godden, also of North Carolina.  I wrote about Enoch Godden last year and you can read that post here.  In that post, I postulated that Enoch Godden was another brother of Nathan and Etheldred Godwin who moved from Randolph Co., NC to Putnam Co., IN in 1828.  The only difference is that somehow Enoch Godwin changed his name to Godden and moved with his son Jonathan Godden to Boone Co., Iowa in 1852, after the death of Etheldred Godwin, who was possibly Enoch’s brother and Sarah Godwin Godden’s Father or Grandfather.

There are several descendants of the Jonathan and Sarah Godden family who are interested in genealogy.  They have even written some books on this family! So we certainly had plenty to share with each other! They were especially interested in how their surname came to be known as “Godden.”  Before I came into their lives, they assumed this was their original surname.  They were even trying to connect to other Godden families! One family of particular interest is the David Godden family of Fayette Co., Iowa. I had come across this family previously in my research as some of his descendants showed up in parts of Indiana. It was also rumored that this David Godden may have been descended from Levi Godden, also of Ohio.  My pool of “cousins” had now extended from just a few to somewhere in the number of the 30s!

The Big Picture….

Ok, so now in the overall Big Picture, we have three possible brothers, Nathan, Enoch, and Etheldred Godwin from North Carolina.

(1) Nathan Godwin thought to be the Father of my ancestor, Elijah Godwin;
(2) Etheldred Godwin had 7 children, 3 sons and 3 daughters and 1 unknown - reference Sarah Godwin; All of the descendants interested in researching this family are from his daughters.
(3) Enoch Godwin, now Godden, has a descendant, Jonathan Godden who is married to his first cousin, Sarah Godwin; His descendants are interested in verifying Enoch Godden was his father and Enoch Godden’s relationship to Etheldred and Nathan Godwin. They are also interested in connecting to other Godden families from the OH-IN area.


The “Plan”… DNA? Huh?

As you may have guessed, this turned into  quite a big research project that spanned over the course of a couple of years, however not without results.  About this same time, I got involved in the Goodwin Surname Project at ftDNA’s hosted site, There were already some 50+ participants who had submitted their DNA to the combined Goodwin/Godwin project and several “groups” had already been formed by lumping similar results together.  My grandfather took the test and submitted his results to the project and his results matched 10 other participants 100%!!! I was so thrilled by this experience that I wanted to share the excitement with my new cousins.

My first goal was to see just how closely related (if at all) my believed ancestor, Nathan Godwin, was to Etheldred Godwin.  Only one problem:  Out of the 30 or so new “cousins” I had met and started corresponding with, not one of them was a descendant of one of Etheldred Godwin’s sons!  Y-chromosome DNA testing requires a direct male to be tested. Ugh

Ok, so it might not always work out the way you want it to.  But then a descendant of Jonathan and Sarah Godwin Godden’s family offered to submit his DNA to the project.  This descendant could possibly be connected to my own Godwin family in two ways because his ancestors were first cousins, however, his DNA will only represent the ancestry of his male ancestor, Jonathan Godwin, the son of Enoch Godwin.  This test was still significant, though, because it showed that Enoch Godwin shared a common ancestor with my ancestors, Elijah and Nathan Godwin in the last 300 years.  You can read about his results in my last post here.

Remember the David Godden family I mentioned above that the descendants of Jonathan and Sarah Godden thought they might be closely related to because they had the same Godden surname?  Well it just so happens that one of David Godden’s (b. 1823, OH) descendants submitted their DNA for testing by last year as well!  I took his results and I put them below the results of my ancestor Elijah Godwin and Jonathan Godden’s descendant’s results (David Godden’s results are listed under “Levi Godden” in the example below). 

Click on image to make it bigger

A screenshot of three sets of marker data for my ancestor, Jonathan Godden’s ancestor, and David Godden’s ancestor. (Some data is missing from Levi Godden’s results because he tested through and the other two tested with ftDNA; the two companies do not test the same markers, therefore making it difficult to make an accurate comparison).

Interpreting the data….

The blue boxes represent markers that do not match.  The markers are listed from left to right no. 1-37. The first marker is 393. The representative value or “modal” is “13 (shown in the solid yellow row).  Below that all 3 sets of testers have 13 as their marker values.  The next value in the modal is 23 for marker 390. Elijah has 23, Jonathan has 23, but Levi Godden has 24 as values. This is the first difference. This is called a “genetic distance.” If you add up the number of blue boxes beside Levi’s name you get 6. However, if you look at marker no. 459a, the modal value is 9, however Levi’s value is 7. This is actually a difference of 2. So you need to add a +1 to the 6 = 7. At this time there are no set standards or rules for determining kinship or how closely related two people are.  The general rule is a genetic distance greater than 3 on a 37 marker test is not genealogically significant, meaning there is probably not a common ancestor within the last 600 years, or since surnames have been in existence.  Therefore, we would not consider Levi Godden to be kin or sharing a common ancestor with Elijah Godwin and Jonathan Godden.

Elijah Godwin and Jonathan Godden do, however, share a common ancestor and it will be up to us cousins to find a paper trail connecting our families. In the meantime, I am on the lookout for male descendants of Etheldred Godwin to participate in the DNA surname project. I am also looking for other male descendants of Jonathan Godden to test because the differences in the marker values between Jonathan Godden’s descendant’s DNA and my Elijah Godwin’s DNA is probably due to mutations that occurred in the last 200 years and the only way to determine when and where these mutations occurred is to look at his other descendants.


  1. Very nice, clear analysis of your project's DNA results. Thanks for posting it!

  2. Thank you CeCe. I thought the post would never end...