This post is a great example of how to get the most from your Y-DNA. In this case we will not only prove a Y-DNA relationship, but also pinpoint the exact location in Ireland where a man's ancestors lived. I will explain the different types of Y-DNA tests, how to do your own evaluations of the results, and give a list of further suggestions on how to get the most from your results and what to do next. This will be a long post.
Can we find immigrant origins when there may be no records?
My father is very proud of his Irish heritage, but he wants to know more. From family tradition he knows that his ancestor, William Gibbs, emigrated to Canada from Ireland. That's the only information that he knew about his Irish origins. Can we find out more?
What we know from Canadian records
William Gibbs is first listed in the 1851 census of Sheffield, Addington County, Ontario. His wife was Mary Coulter, and he is listed in the census next to her parents. The census states that William, his wife, and daughter Mary were all born in Ireland.
| Gibbs family in 1841 census of Sheffield, Ontario, Canada |
William is listed in the 1861 census of Sheffield, but this time the census states that all of his children, including his first daughter, were born in Canada.
| Gibbs family in the 1861 census of Sheffield, Ontario, Canada |
It appears that William may have come to Canada around the time of The Great Famine. There is no passenger list to tell us exactly when he arrived. No record has been found that contains a date of birth or the names of his parents. Luckily, however, his death record [Number 18 in the image below] states that he was born in County Monaghan, Ireland.
| Death of William Gibbs 15 Jun 1882 in Sheffield, Ontario, Canada |
So here's all we know from Canadian records about William's origins: William Gibbs was born around 1826 in County Monaghan, Ireland, and was in Canada by 1851.
Searching records in Ireland
First, as you may know, there is a scarcity of Irish records. In many cases we are stuck with just knowing that our ancestor came from Ireland. But that didn't deter me! After seeing that William was born in County Monaghan I immediately began searching through the records that remain. One of the most useful records for the time when William would have been living in Ireland are the Tithe Applotments. These records were taken between 1823-1837 and can be used as a census substitute. In the entire County of Monaghan, there was not a single Gibbs family. I could not find the family in other surviving records, so I eventually gave up.
An unexpected message
I came to stay with my parents in 2019 to help take care of my mother. She died Christmas morning. I was helping my father when the Coronavirus quarantine was announced, so then I stayed. In March of this year he was talking about his family and said, "About 10 years ago, a man named Jebb contacted me from Ireland and said he thought we might be related." I asked, "What made him think that?" He replied, "DNA." I asked if he still had the email, and he said he didn't, but he thought that he could find the man's email address. A few minutes later I was sending an email to a man in Ireland using an old email address and hoping that he still used it. The next day Mr. Jebb replied. He lives in Ireland, and his ancestors were from the townland of Billis, County Monaghan, Ireland.
Jebb DNA
Mr. Jebb informed me that many years ago he had done a Y-DNA test with Ancestry.com [Ancestry no longer conducts Y-DNA tests]. Other Jebb men had tested at the same company, and some of them were matches. He said he was also a distant match to Gibbs. He was the only Jebb had also taken a 25-marker Y-DNA test with Family Tree Dna, but he did not have any Jebb or Gibbs matches in the FTDNA database. At the time these men were tested, most companies had only one kind of test available for Y-DNA. This was the STR test.
What is an STR test?
"STR" stands for Short Tandem Repeat. A Short Tandem Repeat means that a short series of bases (nucleotides) is repeated side-by-side several times, something like a hiccup.
Here's an STR example: AGATAGATAGATAGATAGATAGATAGATAGAT. In this example, the sequence "AGAT" is repeated eight times. There are many known locations on the Y-chromosome where these Short Tandem Repeats occur. Each of these locations is identified by a marker.
Each marker is given a name such as DYS393. This abbreviation stands for DNA Y-chromosome Segment 393. At this marker the number of repeats is counted and reported. So, for example, in a 12-marker test the testing company will examine 12 named locations on the Y-chromosome and report the number of repeats at each location.
Old Y-DNA tests
After hearing that Jebb had tested at Ancestry and at Family Tree DNA (FTDNA) I was in quite a quandary. My father had not taken Y-DNA tests with either Ancestry.com or with FTDNA. However, he had taken two Y-DNA tests. In 2006 my father had taken a 12-marker Y-DNA test from National Geographic's Genographic Project. I had transferred the results to Family Tree DNA. He had also taken a 43-marker Y-DNA test from the Sorenson Molecular Genealogy Foundation (SMGF). Although SMGF did not display the results, they did publish their database online. As a person guessed at each marker correctly it would show up in the results. I did exactly that, until all results were showing, and then transferred the SMGF results to Ancestry.com and to YSearch.org. SMGF tested 43 markers, but one of these markers was not tested by Family Tree DNA, so only 42 markers are recorded in the YSearch record.
You would think I'd be safe with the DNA in that many databases. But, unfortunately, all but one of them is now gone. Ancestry.com purchased SMGF in 2010, and removed the SMGF online database. Ancestry then discontinued Y-DNA testing and removed its own Y-DNA database. Family Tree DNA removed the YSearch database. This one was the most devastating because I had tested the Y-DNA of hundreds of men. The Y-DNA test of every man from any company had been entered into YSearch, and all were now gone. Most recently, the Genographic Project has been discontinued, and its database has been taken down.
So what did I have left? I had the 12-marker Genographic Project results that had been transferred to Family Tree DNA, and one more thing--I had taken a screenshot of the Gibbs YSearch results.
| Gibbs 42-marker STR results recorded at YSearch.org |
I could compare the Jebb Y-DNA results at Family Tree DNA with the Gibbs 12-marker results that had been transferred there. I immediately looked to see if Jebb was on the Gibbs list of 12-marker Y-DNA matches at Family Tree DNA. He wasn't. Right off the bat, Family Tree DNA is indicating that these two men are not related. If they aren't showing up as matches at only 12 markers, this is not a good sign. But, I still had my YSearch screenshot, and Mr. Jebb allowed me access to his 25-marker Y-DNA results:
| Jebb 25-marker STR results |
By comparing the two we can see how many differences there are. There is already a difference at the second marker, DYS390, where Gibbs has 24, and Jebb has 23. The second difference is at DYS385b where Gibbs has 16, and Jebb has 15. So these two men have two differences in the first 12 markers. A third difference is at DYS447 where Gibbs has 26 and Jebb has 25. This is definitely not looking promising.
But Mr. Jebb also informed me that he had compiled a database of his Ancestry Y-DNA results comparing them to the results of any possible matches. He sent me the list, and I carefully compared them. In addition to his own results there were three matches named Jebb on his list, and my father's Y-DNA results matched all of the men more closely than his results matched Mr. Jebb's. For example, all three of the Jebb matches had a 24 at DYS390. So there was a chance!
I wrote back to Mr. Jebb and told him that our best shot of solving this was to upgrade both the Jebb and Gibbs Y-DNA tests. I said that it was possible that no matter how many STRs we ordered, these two men might still not show up as matches, but if they were really related a Big Y test would prove it.
The most recent version of the Big Y test is called Big Y-700. This test will prove the Jebb-Gibbs relationship because not only does it include more than 700 STRs, it includes the very important SNPs. In addition, the Big Y-700 includes a separate test of the first 111 basic STRs.
| SNPs and STRs (Image by Mark Jobling) |
The main difference between SNPs and STRs is their stability.
STRs can mutate back and forth. For example, in the image above we don't know which of the repeat values came first. Man 1 has CTA repeated 5 times, but CTA is repeated 6 times in Man 2's results and 7 times in Man 3's results. Which is the ancestral value--was it first a 5 that changed to a 6 in Man 2 and then a 7 in Man 3? Or was it first a 6 that mutated down to a 5 in Man 1 and up to a 7 in Man 3? Or was it first a 7 that mutated down in Men 1 and 2? There is no way to tell. Furthermore, these not the only three options--STRs can mutate up in one generation and back down in another generation making two men look more closely related than they really are.
SNPs, on the other hand, are generally one-time events. When a SNP occurs it is passed down to all future generations. Some SNPs are proven to have occurred thousands of years ago. Others occurred in recent times. When a new SNP is found through Y-DNA testing it is given a name and placed on the human Y-DNA tree (called the haplotree). The name of this SNP can become the name of a new haplogroup. A haplogroup is simply a group of men who share a SNP. SNP testing is progressing so rapidly that SNPs occurring in the genealogical time period are being now placed onto the Y-DNA haplotree.
The Big Y test is ordered
The day after I suggested upgrading to Mr. Jebb, I received a reply stating that he had ordered the Big Y on March 7.
I normally wait until the Big Y is on sale to upgrade, but I thought that if I ordered the test right at that time, the 111 STRs might be completed by Father's Day. That would be the best Father's Day present ever if I could show my dad that he was very likely related to Mr. Jebb. So I immediately ordered the Big Y test.
Back to the records
I spent the next few months working almost non-stop reading any records relating to the Jebb family. In case the Y-DNA results showed that these men were really related, I wanted to find the possible Gibbs ancestor (which seemed impossible). I read every Jebb deed, went through surviving church records, etc. For example, although there were no Gibbs families in the Tithe Applotments for County Monaghan there were Jebb families there. The Tithe Applotments can be searched at The National Archives of Ireland where we see that there were fourteen Jebb families listed:
| Index to Tithe Applotments at The National Archives of Ireland |
I wanted to trace all of the Jebb emigrants to see which ones ended up in Canada. I also wanted to find descendants of multiple Jebb lines for possible future Y-DNA tests. This was much more work than I had ever imagined because multiple Jebb descendants had left County Monaghan and emigrated to Scotland, England, India, Australia, Canada, and the United States. Many of them had migrated through multiple countries. I was going through the records in all of these countries compiling lists of Jebb families.
I eliminated many Jebb men as the possible ancestors of William Gibbs, and narrowed it down to just a few. One of them is the best candidate, but since there is no baptismal or other record for William Gibbs the proof can only be provided with Y-DNA.
Y-STR Results
The 111 STR results came in on June 10. Father's Day was June 21, so I had a few days to prepare the presentation of records and to show my father the most exciting news--the DNA results. At 111 markers Mr. Jebb was my father's only match:
| STR match list |
In the Genetic Distance Column you see the number 5. This means that there were five differences between the two men in the 111 markers. We know that two of them occurred within the first 12 markers, and that would normally indicate that these two men are not related.
| Big Y menu: Click Block Tree |
| Block Tree Welcome message |
| Family Tree DNA Y-DNA Haplotree |
| Branch R-BY50723 in Block Tree |
| Y-DNA matches in Big Y Block Tree |
You will notice in Mr. Jebb's branch that it says there is an average of 16 Private Variants between the two men in that branch. Even though these two men are on the same branch of the haplotree, they are not considered to be a match because matches at FTDNA only include people who have no more than 30 total SNP differences which include private variants and named SNPs.
On the Big Y Block Tree, you will see blocks labeled Private Variants. Private Variants are one of the following;
- mutations that are not named nor are shared between any branch members.
- mutations that have not yet been validated and placed on the Haplotree.
It is important to note that Private Variants are filtered to only include SNP calls from regions of the Y chromosome that can be reliably mapped with NGS technology. For this reason, the block tree number might be lower than what you see in your personal Big Y Private Variants list.
| Big Y options |
| Private Variants tab |
| Jebb Private Variants 1-10 |
| Jebb Private Variants 11-20 |
| Jebb Private Variants 21-22 |
| Big Y match list |
| Big Y Block Tree with new match |
The Jebb-Gibbs branch of the tree is the white block on the right. The original R-BY50723 block of 26 SNPs (which was previously shown in white because it was considered to be Mr. Jebb's block) has been now been broken into two blocks called R-BY50725 (9 SNPs) and R-BY50723 (17 SNPs). This is because Jebb and Gibbs both had the SNPs BY50725, BY50788, BY50811, BY50831, BY50848, BY73197, FT123034, FT123036, and FT94586, but they did not have the rest of the SNPs in block R-BY50723 which all of the other men have.
| Estimated SNP Generations |
| Private Variants on Block Tree |
