DNA test – Griffis Family

November 26, 2024November 27, 2024

The Impact of Autosomal DNA Tests: A Profound Discovery

I did not receive ground breaking results from my initial completion of autosomal DNA (atDNA) tests back thirteen years ago. Perhaps I did not totally understand and appreciate how to use the results provided by autosomal tests to the fullest. I think I was more interested in the ethnicity estimates produced by the atDNA than the actual matches with other possible living, distant relatives. When I completed the AncestryDNA test around 2012, autosomal DNA testing was at its commercial infancy. The database of completed tests was comparatively small so the DNA matches were not as notable as they are today. [1]

I had my father and his sister take the tests for my curiosity sake. I wanted to see how the test results differed between each of our tests. My genealogical research at that time was focused on the more traditional aspects of finding historical facts and evidence on various family lines of descent and information on specific individuals.

All this changed when I received a message on October 23rd, 2019. The test results led to a discovery of two half brothers! As an only child, I would at times wonder what it would be like to have brothers.

While I was dumbfounded and flummoxed by the discovery, I have now been gifted with having two brothers through this discovery. Further collaborative work with my half brothers have revealed how this connection unfolded in our lives.

While this news was earth shattering to me, my half brothers and for all families involved, each family has accepted and embraced the genetic revelations. The adoptive parents of Greg, who are still alive, are fully supportive of the three of us establishing family relationships.

Since my half brothers are alive, for purposes of privacy I have only referred to them by their first name in this story.

Discovering Siblings Through Genetic Testing

There are numerous anecdotal stories of people discovering biological family members through atDNA testing. These stories underline that interpreting DNA results often goes beyond sterile numbers. It involves navigating complex emotional territories where understanding ‘shared centimorgans’ can facilitate reconnecting lost, unknown, or separated family members. As such, a shared centimorgan is a powerful tool that can help piece together scattered familial puzzles, reveal hidden secrets and offer not just answers but also emotional closure for many. [2]

“Discovering “new” family members through DNA genealogy testing can trigger a wide range of emotions, including happiness, anxiety, sadness, or even anger. In fact, the emotional experience may be so intense that many genealogy sites state they are not liable for any “emotional distress” that may result from using the service.” [3]

According to studies on direct-to-consumer atDNA testing, a small but significant percentage of people discover they have a full or half sibling they were previously unaware of through their results. This makes it a relatively common occurrence, though not the majority experience for most users. While “sibling” is often used in this context, the discovered sibling could also be a half-sibling (sharing only one parent) [4]

In one study that attempted to gain an understanding of the prevalence of discoveries and associated experiences of atDNA testers, it was found that “most (82%) … learned the identity of at least one genetic relative. Separately, most respondents (61%) reported learning something new about themselves or their relatives, including potentially disruptive information such as that a person they believed to be their biological parent is in fact not or that they have a sibling they had not known about.” [5]

Adoptees often pursue genetic genealogy testing to find biological relatives. Another primary reason for atDNA testing is to gain insights from medical genomic testing. Adoptees understandably seek genetic medical testing for various reasons, primarily related to understanding their health risks and making informed decisions about their medical care in absence of knowing the medical histories of biological kin. They may choose direct-to-consumer testing because of its affordability and accessibility. [6]

Reaching Out and Revealing the Discovery

DNA testing companies typically offer internal communication platforms or features that allow users to reach out to potential DNA matches. While these companies provide communication platforms, users typically have control over their privacy settings and can choose whether to make themselves visible or contactable by matches. Additionally, the specific features and functionality of these communication platforms vary and can be subject to change as companies update their services. [7]

I received an AncestryDNA internal message on October 23, 2019 from David that contained information that not only were we half-brothers, but I had another half brother that was his full brother. It was a lot to mentally and emotionally digest!

October 23, 2019 ancestry.com Internal Mail Message

I thought David did a great job in succinctly conveying a number of points surrounding his discovery. He got straight to the point with the news. He was empathetic to my situation of receiving this news. He also made sure reaching out to me would not cause any ripples in my family. Since his adoptive parents and my parents had passed, he considered the timing of reaching out to me.

David indicated that all the revelations of his having a full and half brother came to light within a three month time period. His discovery of our relationship was the result of completing an AncestryDNA test after he completed a 23andMe test where his full brother Greg discovered the relationship with Dave.

My Immediate Reaction

I was waiting for the car to warm up on a cold fall morning and was quickly going through messages I had received in the night. I was preparing to drive to a remote area for a morning gravel cycling ride. I rarely receive notices from AncestryDNA so Dave’s message caught my eye. I read and reread David’s message a few times. I sat in the car rereading the message for about ten minutes. I decided to digest what I had read on my bike then reach out to Dave when I got home.

I had many thoughts swirling in my head, trying to reconcile potential facts with family history and my father’s colorful life. I was trying to fit all of this together. For my father to have two children from the same person and then give them up for adoption was racking my brain and heart.

At the same time I could only imagine what he must have been going through to follow through this process. We do not know and will never know. He took this part of his life to the grave. I only can make conjectures on what happened and why, given what his life was like at the end of the 1950’s and early ’60’s. I could imagine that he was clearly boxed in by his actions and the subsequent demands placed on his life. Perhaps in his view, his only recourse was to help with the births and adoption. Otherwise the life he knew would have been torn asunder.

My father and mother married when they were 20 and I came along within that year. He was trying to finish college, adjusting to married life, and caring for a family. He was living in a new world full of responsibilities, economic challenges and social pressures. I know that during his 20’s and 30’s, my father enjoyed living in two worlds, one associated with being a father and husband and the other world which was on the edge, staying out late gambling, playing cards and betting on horses and associating with a ‘different crowd’. I witnessed many arguments as a child, not really knowing what the adults were fighting over.

Over time my father became my best friend and best man in my weddings. Since the time I had a ‘consistent paying’ job in the early 80’s, I had called my father at lunch or after work everyday. The calls could have been 30 minutes or a short minute just to say hello. They became part of our ritual. I considered it unique and special to have a best friend and father all wrapped up into one.

While best friends always have secrets, I figured I knew my dad’s past fairly well. I was aware of the good and the not so good in his life.. He had a successful career in sales, was an accomplished regional master’s tennis player, started his own business, and immeasurably helped his family and friends in many ways throughout his life. He had a huge heart and like many, made a few mistakes along the way. His trajectory through life was full of twists and turns. My father had many facets to his life. This was my father that my family knew.

Having two children out of wedlock was certainly a surprise. However, having two children with the same person was more perplexing for me. This reflected something more than a fling or brief encounter. I also wondered but could understand why he never discussed this part of his life to me or others. While I was trying to make sense of this, I looked forward in getting more information from my newly found brothers, Dave and Greg, to figure it out.

When I returned from my bike ride, I wrote an email to Dave full of questions. He was genuinely happy to hear from me. We both harbored no ill will or bad feelings. We both wanted to simply obtain a clear, objective picture of the narrative, he from the adoptive side; and me from the revelation that I have brothers from another relationship of my father’s.

The DNA Results

When I conveyed to my extended family that I had discovered two half siblings through DNA testing, one of my relatives asked, “How do you know if the DNA tests are accurate or legit?“. My direct answer was the results were accurate. My answer, however, was based on both genetic knowledge and also traditional genealogical sleuthing for facts.

Between the three of us, we completed atDNA tests with 23andMe and AncestryDNA. All three of us completed tests with 23andMe. The only DNA test we do not have is an AncestryDNA test for Greg. This test would document the genetic relationship between our father and Greg.

As stated previously, I as well as my father and paternal aunt completed autosomal tests seven years prior to Dave’s discovery. Having my father at the time complete an atDNA test provided prescient knowledge about our family genetics. Dave’s initial AncestryDNA test results indicated that ‘jimgriffis’ was his biological father and that my paternal aunt and I were close family members, possibly first cousins. (See illustration one.)

Illustration One: Dave’s AncestryDNA Autosomal Results

“Half-siblings on Ancestry DNA will show up as “Close Family” or “First Cousins” and are expected to share an average of 1,759 centimorgans with a range of 1,160-2,436 centimorgans, according to data from the Shared Centimorgan Project.” [8]

Half-siblings typically share approximately 25 percent of their DNA, between 1,160-2,436 cMs, and unlike full siblings, do not share fully identical regions (FIR). [9] There is a bit of an overlap of shared cMs for a number of genetic relationships in this cM range. If you do not have other forms of genealogical information, half-sibling DNA patterns can be confused with niece/nephew relationships, aunt/uncle relationships, and grandparent/grandchild pairs.

“When interpreting autosomal DNA statistics, one must be careful to distinguish between the distribution of shared DNA for given relationships and the distribution of relationships for given amounts of shared DNA.” [10]

This overlap is reflected in a genetic relationship chart produced by the Shared cM Project [11], see illustration two below. I have used a cM value of 1722 and 1735 since the atDNA shared cM test value with me for Dave is about 1735 cMs and with Greg is about 1722 cMs for the 23andMe test results. [12]

Illustration Two: Possible Relationships with a cM Value of 1722 and 1735

Aside from the possible relationships that can be found with a cM value of 1722, it is interesting to note the overlap between sibling and half-sibling relationships in illustration two. The cM range for siblings is 1313 – 3488 and the range for half-siblings is 1160 – 2436, with an over lap of 823 cMs.

If we look at the total number of submissions in the Shared cM Project for ‘half-sibling’ relationships, there were 1266 submissions for the Half Sibling relationship with a mean value of 1759 cM and a standard deviation of 207cM. Illustration three provides the distribution frequency of the cM values for half-sibling matches. Basically, a value of 1722 or 1735 is hovering around the middle of the distribution of cM values for half siblings. Hence, my answer to the question of the legitimacy of the test results is the results are pretty solid and reliable.

Illustration Three: Distribution of cM Values for Half Sibling Relationships in the Shared cM Project

The cM test results for matches can differ between DNA companies. For example table one below reflects the estimated cM values for matches between me and my half brothers based on AncestryDNA and 23andMe test results. Both companies report results in different ways. Depending on the DNA company, the predicted relationship is depicted by different measures: the total percentage of shared DNA, the number of shared segments, the length of the shared segments, the longest block of cMs. Different companies may also provide slightly different relationship estimates due to variations in their testing algorithms and reference databases.

Essentially 23andMe provide percent of shared cMs and AncestryDNA provides number of shared cMs to document genetic relationships.

Table One: cM Match Results between Jim, Dave and Greg

cM Share Half-Sibling Relationship with Jim	Percent Shared cM (23andMe)	AncestryDNA Number of matched cMs	cM Conversion using Shared cM Project conversion	Conversion using 68 x % Shared
David	23.32	1685	1735	1585.76
Greg	23.14	– –	1722	1573.52

See footnote [q]

The cM ranges for each of the DNA companies and the Shared cM Project also differ, as reflected in table two.

Table Two: cM Ranges for Half Sibling Relationships

Source	cM Range for Half Sibling
23andMe	1264 – 2529 cM
AncestryDNA	1450 – 2050 cM
Shared cM Project	1160 – 2436 cM

When Dave notified me of our genetic relationship, I revisited and reviewed my DNA matches in AncestryDNA. I had not reviewed my matches in a long time; and there was Dave as a half brother!

The number of shared cMs between my father were similar to the results Dave received in his test results. I shared 3,479 cMs across 26 segments with my father ‘jimgriffis’. Dave shared 3,464 cMs with ‘jimgriffis’ across 57 segments. (See illustrations Three and Four.)

Illustration Four: My AncestryDNA Autosomal Matches

Both Dave and I also have similar matches with our paternal aunt. I share 1,575 cMs and 41 segments with my paternal aunt. Dave shares 1655 and 52 segments with our paternal aunt. The ancestryDNA numbers are within the cM range for an aunt/nephew relationship, as reflected in illustration five..

Illustration Five: Shared cM Project Submissions for Aunt/Uncle

At the beginning of November 2019, I completed an atDNA 23andMe test to validate the DNA connection between the three of us. Before completing the test, I only had a test connection with Dave. The following are the results of my 23and Me atDNA test.

Illustration Six: 23andMe Autosomal Matches

As reflected in illustration six above, the numbers are very close for each half sibling relationship.

Based on the science, half-sibling DNA relationships show distinct patterns that can be reliably identified through atDNA testing. Modern DNA tests can achieve up to 99.9% accuracy for half-sibling relationships when confirming shared centimorgan (cM) ranges, using tests that analyze hundreds of thousands of DNA markers, and including the known parent’s DNA in testing. [13]

As the youtube video below discusses, atDNA tests can identify half-siblings with a high degree of accuracy, additional relationship testing or analysis may sometimes be needed for full confirmation, especially in complex cases. The tests are generally very reliable for distinguishing half-siblings from full siblings or unrelated individuals.

Can atDNA Tests Find Siblings or Half Siblings?

“(A) DNA test can prove half-siblings. As a matter of fact, it’s the only accurate way to establish the biological relationship between the people in question. In a half-sibling situation, the siblings share one biological parent. But you need to test the parent. Here is are the steps involved:

The potential half-siblings need to share 1160-2436 cm.
If the potential siblings are in range AND share more than 1600 cm, there must not be any fully identical regions. If there are, then it’s more likely a full sibling relationship.
Each potential half-sibling must share 2500-3720 cm with the parent.

If all three steps are true, then you’ve got yourself a half-sibling relationship.” [14]

Background of the Full Brothers’ Discovery and Research

Similar to many individuals who were adopted, Dave and Greg completed atDNA tests to understand their medical predispositions and fill gaps in their family health history, which becomes increasingly important as one ages and have children of their own. This information helps providing answers to routine medical questions about hereditary conditions and genetic risks that doctors typically ask during examinations.

In addition to exploring genetic health history, Greg had been trying to find out more about his biological past since 2007. He knew from his adoptive parents that he was born in Rochester, New York. The adoption agency in Rochester sent him a note back in 2007 that stated his father was a salesman, married, and his mother was a nurse. Both were college educated. The father helped with the costs of birth and adoption. The note stated that ‘both parents were very religious and the controversy would have been too much so adoption was the solution‘.

In the summer of 2019 Greg discovered Dave as a full brother from a 23andMe match after Dave completed the test. Similar to Greg, Dave also completed the 23andMe test at his wife’s behest, to gain knowledge about his genetic medical past. At the time, Dave said he did not have much faith in the results.

Greg reached out to Dave on July 29, 2019 with “Hello Bro” as the subject line in an email. This started the ball rolling. According to the 23andMe analysis, they both are full siblings.

After this email, Dave started a concerted effort at obtaining additional information about his biological past. Greg had been conducting research previously and tracked their mother, Esther, to Arizona and her marriage in 1973 and her subdeath in 1996. Esther was a nurse by profession. Her nursing career took her many places, from Albany, New York to New Haven, Connecticut, to Alaska, and then to Phoenix, Arizona where she was married and had three sons. Through their collective efforts, Dave and Greg discovered four half siblings!

Using various sources, Dave started to piece together Esther’s family who was originally from the Kingston, New York area. He found a friend of Esther’s and nursing school classmate of Esther’s named Phylis Hutton. Both started their nursing careers in Albany, New York.

When Dave discovered Phylis in 2019, she was in her 80’s and living in Kingston, New York. He had a short telephone conversation with her. She indicated she remembered and knew about Esther going to Pittsfield to have a child. Dave was born in Pittsfield, Massachusetts. Dave asked if she knew of the father. She said she did not remember the name but she recalled that his father was a reverend and recalled that he was an orderly at the hospital and that ‘he was extremely handsome’.

Newspaper Announcement – Esther Emerick and Phyllis Hutton

A short time after his call with Phyllis, Dave received another call from a newly found first cousin from his biological mother’s side. His cousin was contacted by Phyllis about the news and her telephone call with Dave. Dave’s first cousin then received information from another cousin and advised Dave to follow up on a name ‘James D. Griffis’ from Troy, NY. The cousin stated that his father was Harold W Griffis, a prominent minister back in the 1950s-1960s. It was thought that James was Esther’s suitor at the time and that James had a brother John and a sister.

In early August 2019, Dave received his pre-adoption birth certificate. The father was not listed but his mother was listed as Esther Emerick, born 1938, Kingston, New York.

Working Together: Verifying Facts, Time and Place

At the time Dave initially reached out to me, the historical information regarding their biological father did not entirely jibe between Greg and Dave’s research. The biological father on both Dave and Gregs’ adoption forms indicated that their father was a salesman. Phyllis Hutton, from Esther’s nursing past, indicated that the father was an orderly at the hospital that she and Esther were employed in Albany. Before his passing, Dave’s adoptive father indicated that he knew his biological father was a salesman and his biological mother was a nurse.

To obtain additional or potential new leads, Dave completed an ancestry.com DNA test to see if people would show up as close relatives. He received his results October 17, 2019. He opened the results and looked at DNA matches on October 21, 2019. I, Nancy, and my father showed up as close relatives. Dave then sent me the note on the 22nd of October.

After a few email exchanges, Dave and I scheduled a telephone conversation about a week after his initial contact with me. We had a two hour conversation on many subjects. One part of the conversation, tied the facts and events together.

My dad was a salesman but he also had a second job as an hospital orderly around 1959 – 1961. This would explain the discrepancy between the stated occupation on the adoption documents and oral history that was obtained from Esther’s family and friend.

I recalled my father working nights when I was in first grade. I recall one time meeting my father with my mother in our car one morning near a big brick building which was the Albany Medical center. The adults were talking. but I paid little attention to what was discussed. As a child in the back seat of the car, I recall my Dad leaning into the window as he was standing beside the car. I did not listen but I recall my Dad saying at the end of teh conversation, “Well, I need to go to my other job now” and they said their goodbyes and my mother drove on to do errands.

When my father got married, my paternal grandparent’s ‘social contract’ with my father was that they would financially help him with college until he got married. Once he got married, he was on his own, he had to pay for his own education and living costs.

My parents married when my father was a Junior in college. My dad subsequently worked two jobs to support a family and school costs. I was born while he was in college. One of his two jobs was working as an hospital orderly in the state mental institution on the night shift while he finished college.

After graduation, he and his young family moved back to the Troy, New York area. He continued his colorful ways. He accrued a lot of debt probably through gambling. He received financial assistance from his brother’s father-in-law who was a banker.

I believe this was a melting point for him, for my mother, and his parents Harold and Evelyn. He needed funds to supplement his current standard of living associated with his day job to pay off the debt. He again got a night job based on the skill sets he knew he had – being an orderly at Albany Medical.

I told all of this to Dave and asked when and where his mother was a nurse in Albany. Dave directed me to the newspaper article above. She was nurse at Albany Medical in 1959-1960. Phyllis’ story started to make sense. My dad was a salesman at Kimmey Company, a plumbing construction company, and also an orderly at Albany Medical.

Dave was born in 1960 in Pittsfield, MA. His brother Greg was born in 1961 in Rochester, NY. Based on information gleaned from Dave and Gregs’ adoption papers, our father was fully aware of their births and it appears he provided financial support to Esther in the birth and adoption process.

Non-Marital Pregnancies and Adoptions in the late 1950s and early 1960s

Having and keeping a child out of wedlock would have been quite a challenge for Esther. Esther was from a ‘prominent religious oriented’ family in Kingston, New York. The possibility of raising two children out of wedlock was inconceivable. James had a young family, was married to a practicing Catholic wife and was raised by a Methodist minister. Based on their upbringing, abortion was not a moral choice for both Esther and James even if it were legally available at the time. For various unknown reasons on both sides, divorce was not an option as well.

Esther was starting her nursing career in 1959. To have two children and be a single mother back to back in 1960 and 1961 would have been daunting. I can only imagine the stress and social and economic challenges that must have been placed on our father, Esther and my mother. I do not know if my mother was aware of the births. I assume that she was aware.

This was a period in American history that was known as the Baby Scoop Era. It started after the end of World War II and ended in the early 1970s, characterized by an increasing rate of pre-marital pregnancies over the preceding period, along with a higher rate of newborn adoption. [15]

“It was common knowledge that many white unwed mothers had the resources to conceal their pregnancies, often by traveling far from home to have their babies, to states that didn’t record illegitimacy on birth certificates. ” [16]

The ability to avert having a child in the late 50’s was difficult given the limited options for contraception and the legal and religious prohibitions placed on abortion. For non-wed mothers, the viable option was having the child and offering the child up for adoption.

The legal status and accessibility of birth control was severely restricted by the 1873 Comstock Law, which criminalized contraceptives and banned their distribution through mail or interstate commerce. [17]

In the 1950s, “Americans spend an estimated $200 million a year on contraceptives. Due to massive improvements over the past decade in condom quality and a growing awareness of the inadequacies of douches, “rubbers” are the most popular form of birth control on the market.

“Although the vast majority of doctors approve of birth control for the good of families, anti-birth control laws on the books in thirty states still prohibit or restrict the sale and advertisement of contraceptive devices. It is a felony in Massachusetts to “exhibit, sell, prescribe, provide, or give out information” about them. In Connecticut, it is a crime for a couple to use contraception.” [18]

The year that Dave was born, “(t)he adoption of the birth control pill grew rapidly after its FDA approval on June 23, 1960. 400,000 women sought prescriptions in the first year, despite the high cost of $10 (equivalent to $80 today).” [19] The first pill, Envoid, in addition to prohibitive cost, it also produced some negative side effects: nausea in the first few months and weight gain.

In the 1950s, abortion was heavily restricted across the United States with severe consequences for both providers and women seeking the procedure. By 1950, abortion was illegal in every state except when necessary to save the woman’s life. Forty-four states only permitted abortion when the woman’s life was endangered. [20]

By the middle of the twentieth century, almost every state in the country had brought their adoption laws into alignment with the principles laid out by two influential groups: the U.S. Children’s Bureau (USCB) and the Child Welfare League of America (CWLA) guidelines and the Child Welfare League of America. [21]

“The USCB was created by the federal government in 1912 as a Progressive Era organization that introduced public health interventions to reduce infant mortality. It also became a national leader in making policy related to illegitimacy and unmarried mothers. The group was motivated by multiple scandals with commercial and unregulated adoptions that had lethal consequences for the infants. The CWLA, which brought together public and private service groups starting in 1915, later initiated efforts to standardize adoptions that culminated with its influential 1958 publication Standards for Adoption Service.” [22]

By the late 1940s, existing service organization like the National Florence Crittenton Mission—later called the Florence Crittenton Association— encouraged single mothers it served to relinquish their infants. It is not known if Dave and Greg were born in a Maternity home in Pittsfield and Rochester. [23]

Figures vary for the number of adoptions during the postwar decades, since most of them went unrecorded. One source indicates the number of adoptions more than doubled (128 percent) from an estimated 50,000 in 1945 to 114,000 in 1961, the year that Greg was born. As reflected in illustration seven, Dave (born 1960) and Greg (born 1961) were born and adopted in a period where there was a steady rising nationwide wave of adoptions. [24]

Illustration Seven: Adoption Trends 1944 – 1961

“The heyday for domestic adoption was the mid-20th century. Between 1940 and 1964, the rates of so-called “illegitimate” pregnancy doubled and tripled, from 89,500 in 1940 to 275,700 in 1964.” [25]

Family Support

Without judgement, I shared the surprising discovery of having two half-siblings to my immediate and extended family in an e-mail. I concluded with the following:

“Each of you had a unique relationship with my father. Based on that relationship, I am confident to state that he treated you like, as he would say, aces. He was there for you and loved you dearly even when there were hard times. So I hope before you cast judgment, as he would do, you see through your heart and then open your arms.“

I told Dave and Greg that I was very happy that they have found answers to questions that I imagine adopted children always have in the back of their minds. I told them I hoped they have or had wonderful parents and their life was good. I also told them I welcomed them as my brothers and looked forward to having them in my life. As an only child I always longed to have brothers.

Many of my family members replied to this news. One of my aunts indicated, “Jim was a young wild character and got into a lot of trouble with his marriage to Peggy, gambling and finances, and his relationships with other women. He grew up the hard way over his lifetime and became the loyal person we love and admire. He extended his care and loyalty to all of us.”

One of my cousins said in a reply to my email:

“I love that this family can accept this type of news- hold Uncle Jim accountable for the affairs, but forgive, love, and move forward, free of judgement. We truly are a class act clan!“

My cousin’s sentiment sums up the common sentiment I have received from family members. We as a family are strong, tolerant, have a good sense of humor and full of different personalities. We all are not perfect and if someone takes a misstep, we help them regain their balance. When you are connected by so much family and love, forgiveness and collectively moving on in life is much easier.

I know David and Greg appreciate the positive support. In addition to our communication, I have provided copies of a commemorative book I created that chronicles our father’s life. The book gives them an idea of what their biological father was like throughout his life.

Conversely, I have been introduced to many of Dave’s friends and his family on ‘his turf’. I have also have communicated with Greg’s step-parents who are proud and happy that we have found each other.

This is a photograph of a holiday gift I had given to each of my brothers in 2024. This is Dave’s coffee mug in use.

Moving Forward and Continuing the Journey

Discovering siblings late in life can be a complex and emotionally charged experience, involving a mix of excitement, confusion, curiosity, and sometimes even grief, as individuals grapple with a new family dynamic, a revised understanding of their identity, and the potential for a significant relationship that was previously unknown. This can be influenced by the circumstances surrounding the discovery, like adoption, family secrets, or a parent’s hidden past, leading to varying levels of adjustment and impact on personal relationships.

For Dave, Greg and me, I think we handled the discovery with excitement, gratitude and promise. We are in agreement that it would have been nice if we were able to experience having our brothers in our lives when we were in earlier stages of our lives. In absence of the shared past, we are grateful to presently have each other in our lives.

We discovered our relationship as siblings when we ranged in ages of 59 to 66. We do not have shared histories as children, adolescents, young adults, and when we went through mid-life experiences. We were not there for each other through our ups and downs. Our bond lacks all those experiences of ‘growing up’. Our bond is based on our unique past and the future, learning about each other’s past life and our respective families, and presently enjoying our time together as brothers.

A Zoom Call

Since the beginning of 2020, we have been attempting to arrange a time when all three of us can get together. Sad to say our schedules have not yet been able to coincide. As twosomes, we all have gotten together on various occasions. We do not live close to each other and we each have family demands. My two younger brothers are still working so they have the added demands of work life. I am confident the three of us will enjoy time together in the future and be part of each other’s lives.

Dave and Jim September 2021

Jim and Greg Thanksgiving Weekend 2024

Echoing a title of a book of an adoptee’s journey through the American adoption experience: ‘You don’t know how lucky you are!“. [26]

I think this statement is true for Dave and Greg … as well as for me.

Sources

Feature Image: This is a modified version of an illustration from Pereira, Rita, Pietro Biroli, Stephanie Von Hinke, Hans Van Kippersluis, Titus Galama, Niels Rietveld, and Kevin Thom. 2022. “Gene-environment Interplay in the Social Sciences.” OSF Preprints. 4 March 2022 DOI:10.31219/osf.io/d96z3; and a stock photo https://stock.adobe.com/

[1] Autosomal DNA testing has undergone significant changes and improvements since its introduction in 2009. 23andMe launched the first autosomal DNA test for genealogy in late 2009, marking a revolutionary change in genetic genealogy. This test allowed people to examine DNA inherited from all ancestral lines.

Family Tree DNA launched their Family Finder test in February 2010. AncestryDNA began rolling out their autosomal DNA test in the autumn of 2011, with an official launch in the United States on May 3, 2012. They initially kickstarted their database by offering free tests to over 10,000 selected subscribers. AncestryDNA reached 2 million users by August 2016.

The database showed exponential growth until April 2018. Growth slowed after April 2018, adding 6 million people instead of the projected 12 million in the following year. Database growth declined by 51% from April 2018 to May 2019. By 2021, AncestryDNA led the pack in database size with over 20 million completed test kits.

By 2014, AncestryDNA’s database had grown rapidly, selling 30,000 to 50,000 DNA kits monthly. The test became available internationally when AncestryDNA launched in the UK and Ireland in 2015, followed by expansion to 29 additional countries in February 2016.

Testing accuracy has improved significantly over time. Early ethnicity estimates were often inaccurate. Current continental-level results are now highly reliable.

Genealogical DNA test, Wikipedia, This page was last edited on 18 November 2024, https://en.wikipedia.org/wiki/Genealogical_DNA_test

History of genetic genealogy, International Society of Genetic Genealogy Wiki, This page was last edited on 27 April 2024, https://isogg.org/wiki/Timeline:History_of_genetic_genealogy

Doriottt, Candace, Genetic Codes Unraveled: New Clues to Human History. Ancestry magazine, January/February 2000, Page 15 – 21

Theunissen, C.A. The Effects of DNA Test Results on Biological and Family Identities. Genealogy 2022, 6, 17. https://doi.org/10.3390/genealogy6010017

AncestryDNA at Back To Our Past, 12 Nov 2014, Cruwys News, https://cruwys.blogspot.com/2014/11/ancestrydna-at-back-to-our-past.html

Williams, Ed, Analysis of AncestryDNA Tests Processed from June 2016 to August 2019, 12 Dec 2019, Counting Chromosomes, https://countingchromosomes.com/blog/70-analysis-of-ancestrydna-tests-processed-from-june-2016-to-august-2019

Venner, E., Patterson, K., Kalra, D. et al. The frequency of pathogenic variation in the All of Us cohort reveals ancestry-driven disparities. Commun Biol 7, 174 (2024). https://doi.org/10.1038/s42003-023-05708-y

Genealogical Database Growth Slows, 22 Jun 2019,The DNA Geek, https://thednageek.com/genealogical-database-growth-slows/

AncestryDNA Surpasses 20 Million, 27 May, 2021, The DNA Geek, https://thednageek.com/ancestrydna-surpasses-20-million/

[2] See for example:

Catherine A. Ball, Mathew J Barber, Jake Byrnes, Peter Carbonetto, Kenneth G. Chahine, Ross E. Curtis, Julie M. Granka, Eunjung Han, Eurie L. Hong, Amir R. Kermany, Natalie M. Myres, Keith Noto, Jianlong Qi, Kristin Rand, D. Barry Starr, Yong Wang and Lindsay Willmore, AncestryDNA Matching White Paper, Updated July 15, 2020, AncestryDNA, https://www.ancestrycdn.com/support/us/2020/08/matchingwhitepaper.pdf

Topor, David, Genealogy testing: Prepare for the emotional reaction, Jun 6 2018, Harvard Health Blog, https://www.health.harvard.edu/blog/genealogy-testing-prepare-for-the-emotional-reaction-2018060613990

Guida-Richards, Melissa, My Half Siblings Found Me On 23andMe. I Wasn’t Prepared For What Happened Next, May 28, 2020, HuffPost, https://www.huffpost.com/entry/discovered-siblings-reunited-23andme-dna-test_n_5e690e55c5b60557280f743e

Kaiser, Molly, I’m 22 and I just met my half sister for the very first time. Here’s how it went, Sep 30, 2022, Today, https://www.today.com/health/essay/dna-test-met-half-sister-rcna49840

Williams, Brianne Kirkpatrick, Watershed DNA, https://www.watersheddna.com/blog

Daniella, I Found My Birth Parents and 7 Half-Siblings Thanks to a MyHeritage DNA Test, Apr 6 2023, MyHeritageBlog, https://blog.myheritage.com/2023/04/i-found-my-birth-parents-and-7-half-siblings-thanks-to-a-myheritage-dna-test/

Imbeault, A DNA test revealed a sister I never knew existed. Now what?, Sep 17 2019, The Globe and the Mail, https://www.theglobeandmail.com/life/first-person/article-a-dna-test-revealed-a-sister-i-never-knew-existed-now-what/

Milligan, Kate, An Only Child’s DNA Surprise, 23andMe Blog, https://blog.23andme.com/articles/an-only-childs-dna-surprise

Molina, ‘Kimberly, My stomach dropped’: Half-sisters find each other through ancestry search, Oct 09, 2018, CBC, https://www.cbc.ca/news/canada/ottawa/half-sisters-discovery-ancestry-dna-1.4849559

Ventura, Risell, Man discovers 18 half-siblings after 23andMe DNA test, Jan 6 2022, 2KUTV, https://kutv.com/news/offbeat/man-discovers-18-half-siblings-after-23andme-dna-test

Hauswirth, Heather, How a DNA test led me to the brother I never knew existed, Nov 14 2018, New York Post, https://nypost.com/2018/11/14/how-a-dna-test-led-me-to-the-brother-i-never-knew-existed/

Segalov, Michael, I took a DNA test and found a new family’: the drama and joy of meeting long-lost relatives, 21 ov 2021, The Guardian, https://www.theguardian.com/global/2021/nov/21/i-took-a-dna-test-and-found-a-whole-new-family

[3] Topor, David, Genealogy testing: Prepare for the emotional reaction, Jun 6 2018, Harvard Health Blog, https://www.health.harvard.edu/blog/genealogy-testing-prepare-for-the-emotional-reaction-2018060613990

[4] Guerrini CJ, Robinson JO, Bloss CC, Bash Brooks W, Fullerton SM, Kirkpatrick B, Lee SS, Majumder M, Pereira S, Schuman O, McGuire AL. Family secrets: Experiences and outcomes of participating in direct-to-consumer genetic relative-finder services. Am J Hum Genet. 2022 Mar 3;109(3):486-497. doi: 10.1016/j.ajhg.2022.01.013. Epub 2022 Feb 24. PMID: 35216680; PMCID: PMC8948156, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8948156/

Lee H, Vogel RI, LeRoy B, Zierhut HA. Adult adoptees and their use of direct-to-consumer genetic testing: Searching for family, searching for health. J Genet Couns. 2021 Feb;30(1):144-157. doi: 10.1002/jgc4.1304. Epub 2020 Jun 29. PMID: 32602181, https://pubmed.ncbi.nlm.nih.gov/32602181/

Roberts JS, Gornick MC, Carere DA, Uhlmann WR, Ruffin MT, Green RC. Direct-to-Consumer Genetic Testing: User Motivations, Decision Making, and Perceived Utility of Results. Public Health Genomics. 2017;20(1):36-45. doi: 10.1159/000455006. Epub 2017 Jan 10. PMID: 28068660, https://pubmed.ncbi.nlm.nih.gov/28068660/

[5] Guerrini CJ, Robinson JO, Bloss CC, Bash Brooks W, Fullerton SM, Kirkpatrick B, Lee SS, Majumder M, Pereira S, Schuman O, McGuire AL. Family secrets: Experiences and outcomes of participating in direct-to-consumer genetic relative-finder services. Am J Hum Genet. 2022 Mar 3;109(3):486-497. doi: 10.1016/j.ajhg.2022.01.013. Epub 2022 Feb 24. PMID: 35216680; PMCID: PMC8948156, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8948156/

[6] Casas KA. Adoptees’ Pursuit of Genomic Testing to Fill Gaps in Family Health History and Reduce Healthcare Disparity. Narrat Inq Bioeth. 2018;8(2):131-135. doi: 10.1353/nib.2018.0050. PMID: 30220696, https://pubmed.ncbi.nlm.nih.gov/30220696/

[7] several DNA testing companies offer communication platforms to connect with genetic matches.

23andMe offers a “DNA Relatives” feature where users can contact matches after they agree to share genome.
Family Tree DNA allows direct email communication with matches6.AncestryDNA provides an internal messaging system for contacting matches.
MyHeritage uses its own messaging system for match communication.
Living DNA includes a messaging system to reach out to genetic matches.

Autosomal DNA testing comparison chart, International Society of Genetic Genealogy Wiki, This page was last edited on 8 October 2024, https://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart

[8] McDermott, Marc, How Do Half-Siblings Show Up on Ancestry DNA?, GenealogyExplained, 23 Dec 2022, https://www.genealogyexplained.com/how-do-half-siblings-show-up-on-ancestry-dna/

[9] FIRs (Fully Identical Regions) are genetic segments that are shared between individuals. These regions represent areas of DNA where both chromosomal copies are identical between the compared individuals.

[10] Autosomal DNA Statistics, This page was last edited on 17 October 2022, International Society of Genetic Genealogy Wiki, https://isogg.org/wiki/Autosomal_DNA_statistics

[11] The Shared cM Project (ScP) is a collaborative data collection and analysis project that helps genealogists understand DNA relationships by documenting the ranges of shared centimorgans (cM) associated with various known family relationships. The project contains over 60,000 submissions from genealogists and provides probability estimates for different relationship types based on shared DNA amounts.

Bettinger, Blaine, Version 4.0! March 2020 Update to the Shared cM Project!, 27 Mar 2020, The Genetic Genealogist, https://thegeneticgenealogist.com/2020/03/27/version-4-0-march-2020-update-to-the-shared-cm-project/

Bettinger, Blaine & Jonny Perl, The Shared cM Project 4.0 tool v4, 26 Mar 2020, DNA Painter, https://dnapainter.com/tools/sharedcmv4

Perl, Jonny, Shared cM histograms: did you know? #3, 12 Apr 2023, DNA Painter Blog, https://blog.dnapainter.com/blog/shared-cm-histograms-did-you-know-3/

Shared cM | How Am I Related to My DNA Matches?, Your DNA Guide, https://www.yourdnaguide.com/shared-cm-project

[12] The cM test results for matches can differ between DNA companies. For example the table reflects the estimates cM values for matches between me and my half brothers based on AncestryDNA and 23andMe test results.

These cM values are based on converting the percentage of shared cM values obtained in the 23andMe atDNA test results. Since 23andMe only provides percent of shared cMs between me and Dave or greg, you need to use a conversion procedure:

There are two ways to convert 23andMe matches to centimorgans (cM), you can use the Shared cM Project tool at DNA Painter:

Go to the Shared cM Project tool at DNA Painter
Enter the percentage of shared DNA in the percentage box
The tool will show you the cMs

Bettinger, Blaine,, The Shared cM Project 4.0 Tool v4, Mar 2020, DNA Painter, https://dnapainter.com/tools/sharedcmv4

You can also use a ‘quick and dirty’ approach to convert the percentage into centimorgans by just multiplying your percentage by 68.

Cooke, Lisa, What’s a CentiMorgan, Anyway? How DNA Tests for Family History Measure Genetic Relationships, 23 Oct 2017, Genealogy Gems, https://lisalouisecooke.com/2017/10/23/genetic-relationships-centimorgans/

Fully identical region, This page was last edited on 1 April 2022, International Society of Genetic Genealogy Wiki, https://isogg.org/wiki/Fully_identical_region

Estes, Roberta, Pedigree Collapse and DNA – Plus an Easy-Peasy Shortcut, 31 Jan 2024, DNAeXplained – Genetic Genealogy, https://dna-explained.com/category/fully-identical-regions/

Hill-Burns, Erin, How much DNA in FIRS(Fully Identical Regions) do relatives share?, Genes & History, https://genesandhistory.wordpress.com/2019/12/04/how-much-dna-in-firs-fully-identical-regions-do-relatives-share/

DNA Geek, AncestryDNA Is Using FIRs to Distinguish Full and Half Siblings, 7 Feb 2019, TheDNAGeek, https://thednageek.com/ancestrydna-is-using-firs-to-distinguish-full-and-half-siblings/

SegcM | DNA Science, Relationship predictions that use both the # of segments and total cMs https://dna-sci.com/tools/segcm/

DNA-Sci, Segments Matter! , 3 Feb 2023, DNA Science Blog, https://dna-sci.com/2023/02/03/segments-matter/

[13] McDermott, Marc, How Do Half-Siblings Show Up on Ancestry DNA?, GenealogyExplained, 23 Dec 2022, https://www.genealogyexplained.com/how-do-half-siblings-show-up-on-ancestry-dna/

What is the best test for showing that two people are half siblings? 7 Jan 2016, The Tech Interactive, https://www.thetech.org/ask-a-geneticist/articles/2016/best-half-sibling-dna-test/

Estes, Roberta, Full or Half Siblings?, 3 Apr 2019, DNAeXplained – Genetic Genealogy, https://dna-explained.com/2019/04/03/full-or-half-siblings/

[14] McDermott, Marc, How Do Half-Siblings Show Up on Ancestry DNA?, GenealogyExplained, 23 Dec 2022, https://www.genealogyexplained.com/how-do-half-siblings-show-up-on-ancestry-dna/

Stocker CM, Gilligan M, Klopack ET, Conger KJ, Lanthier RP, Neppl TK, O’Neal CW, Wickrama KAS. Sibling relationships in older adulthood: Links with loneliness and well-being. J Fam Psychol. 2020 Mar;34(2):175-185. doi: 10.1037/fam0000586. Epub 2019 Aug 15. PMID: 31414866; PMCID: PMC7012710. https://pmc.ncbi.nlm.nih.gov/articles/PMC7012710/

Segments Matter!

[15] Baby Scoop Era, Wikipedia, This page was last edited on 22 October 2024,, https://en.wikipedia.org/wiki/Baby_Scoop_Era

[16] Solinger, Rickie, Wake Up Susie: Single Pregnancy and Race Before Roe v. Wade, New York: Routledge, 2000, Page 102

[17] The Comstock Act of 1873 severely restricted access to birth control in the United States through several key measures. It criminalized mailing or distributing any contraceptive devices or information about contraception. Imposed harsh penalties including fines of $100-$5,000 and imprisonment of 1-10 years for violations. Led to thousands of arrests and the destruction of hundreds of tons of books and educational materials about contraception.

The Comstock Act prevented women from accessing information about their reproductive health and pregnancy prevention options. It banned doctors and social reformers from providing contraceptive information to patients. State-level “Comstock laws” further expanded restrictions on contraception, with some states like Connecticut completely banning birth control use. The Comstock Act’s restrictions on contraception remained technically in effect until 1971, when Congress finally removed the language related to contraceptives from the law.

Wexler, Ellen, The 150-Year-Old Comstock Act Could Transform the Abortion Debate, 15 Jun 2023, Smithsonian Magazine, https://www.smithsonianmag.com/history/comstock-act-transform-abortion-debate-180982363/

Comstock act, Women & the American Story, The New York Historical, https://wams.nyhistory.org/industry-and-empire/fighting-for-equality/comstock-act/

Birth control in the United States, Wikipedia, This page was last edited on 12 November 2024, https://en.wikipedia.org/wiki/Birth_control_in_the_United_States

Comstock Act of 1873 Wikipedia, This page was last edited on 15 November 2024, https://en.wikipedia.org/wiki/Comstock_Act_of_1873

[18] A Timeline of Contraception, American Experience, PBS, https://www.pbs.org/wgbh/americanexperience/features/pill-timeline/

Birth control in the United States, Wikipedia, This page was last edited on 12 November 2024, https://en.wikipedia.org/wiki/Birth_control_in_the_United_States

[19] Gibson, Megan, One Factor That Kept the Women of 1960 Away From Birth Control Pills: Cost, 23 Jun 2015, Time, https://time.com/3929971/enovid-the-pill/

Y-DNA and the Griffis Paternal Line Part Four: Teasing Out Genetic Distance & Possible Genetic Matches

This is part four of a story on utilizing Y-DNA tests to gain knowledge or leads on the patrilineal line of the Griff(is)(es)(ith) family. This part of the story focuses on the analysis of Y-STR test results to possibly locate genetic ancestors.

Working with Y-STRs (and Y-SNPs) and the various types of tests and Y-DNA tools requires covering the topics of genetic distance, modal haplotypes, ancestral haplotypes and the Most Recent Common Ancestor.

Most Common Ancestor: A Peculiar Concept

A number of genetic studies argue that all humans are related genealogically to each other over what can be considered as surprisingly short time scales. [1] Few of us have knowledge of family histories more than a few generations back. Moreover, these ancestors often do not contribute any genetic material to us [2] .

In 2004 mathematical modeling and computer simulations by a group of statisticians indicated that our most recent common ancestor probably lived no earlier than 1400 B.C. and possibly as recently as A.D. 55. Additional simulations, taking into account the geographical separation of continents and islands and less random patterns of mating in real life suggest that some populations are separated by up to a few thousand years, with a most recent common ancestor perhaps 76 generations back (about 336 BCE), though some highly remote populations may have been isolated for somewhat longer [3]

The most recent common ancestor of a group of men and the most common ancestor of man are concepts used in genetic genealogy. Their definition and explanation are not entirely intuitive. They can be difficult to comprehend and what do they actually mean. For most of us it is a bit difficult to accept or even comprehend concepts that rest on mathematics or statistics and not hard data. Archaeologists, genealogists, or historians will never uncover ancient artifacts or documentation that identify your most recent common ancestor.

The idea of a genealogical common ancestor resists attempts to demonstrate its existence with a genetic, DNA equivalent. As special as either of ‘these recent individuals’ are within our genealogy, it is very likely that most living people have inherited no DNA from these individuals at all.

This may seem like a paradox: a genealogical ancestor of everybody, from whom most of us have inherited no DNA. It reminds us that genetic and genealogical relationships are different from each other. Many close genealogical relatives are nonetheless genetically and culturally very different from each other. Fifth cousins are not far apart genealogically, but they sometimes share no DNA from their common genealogical ancestors at all. [4]

The following video provides an excellent overview of the interplay between different concepts of genealogy and their implications. The video also touches on the concept of common ancestor, identical ancestors point (IAP), or all common ancestors (ACA) point, or genetic isopoint, and the most recent ancestor. [5]

Genetic Distance

While I brought up the concept of most common ancestor for discussion, our main concern is really with something that is more manageable to comprehend in terms of genetic distance: genetic distance based on the most recent common ancestor. It still might be confusing but not mind blowing.

Genetic distance, is a concept used more as an operational concept by FamilyTree DNA (FTDNA). It is a concept that ranks individual test kits according to how close they appear to be to each other based on the number of allele differences on designated short tandem repeats (STRs).

Genetic distance can also be calculated using Single-nucleotide polymorphisms (SNPs) by comparing the time distance between different haplogroup branches. For the most part the concept is used in the context of comparing genetic test results between two or more Y-STR test kits to determine if they are genetically ‘closely related’. [6]

Genetic distance is based on the analysis of STR data, is the result of calculating the number of mutation events which have occurred between two or more individuals in their respective haplotypes. The more STR’s sampled and compared, the more reliable is the estimate of genetic distance.

Most Common Recent Ancestor

In genetic genealogy, the most recent common ancestor (tMRCA) of any set of individuals is the most recent individual from which all the people in the group are directly descended. [7] Estimating TMRCAs is not an exact science. Because it is not an exact science, questions and answers regarding TMRCA should be phased in general terms. For example, is the MRCA likely to be within the time of surnames or is the MRCA more likely to be in the 1`700’s or the 1600’s. Generally, TMRCA concept can be used to give a working theory or hypothesis about which general time frame the common ancestor may have lived.

The results of various type of analyses that calculate genetic distance will point to the most recent common ancestor of a group of men.

The information in Table One was introduced in Part Three of this story and will be used as a basis for discussing my path of discovery for genetic ancestors using the concept of genetic distance and tMRCA. The table displays Y-Chromosome DNA (Y-DNA) STR results for testers in the L-497 Haplogroup project. As reflected in Illustration One, twelve test kits were grouped together based on how they tested for specific SNPs associated with branches in the haplotree.

Illustration One: The One Two Punch of SNP then STR Analysis

Specifically, Table One provides STR data on my haplotype (STR signature), which is highlighted in the table, for 111 sampled STR values. My results are grouped with eleven other men based on our similarity in our respective STR haplotype signatures. We also share similarities in SNP tests and have been grouped in the G-BY211678 haplogroup.

Table One: 111 STR Results for G-L497 Working Group Members within the G-BY211678 Haplotree Branch

Source: FTDNA DNA Results for Y-DNA Group Members of Haplogroup L-497 within the FY211678 haplotree branch | **Click for Larger View**

The table provides the modal haplotype for the twelve individuals (re: third row) and the minimum and maximum values for each of the STRs listed in the table. FTDNA uses the concept of genetic distance (GD) to compare and evaluate genetic resemblance of two or more STR haplotypes. It is at this point we start to compare STRs among potential test kits.

Genetic Distance: What Does It Mean, How is it Used & How to Portray It

A haplotype (haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. [8]

Unlike other chromosomes, Y chromosomes generally do not come in pairs. Every human male (excepting those with XYY syndrome) has only one copy of that chromosome. This means that there is not any chance variation of which copy is inherited, and also (for most of the chromosome) not any shuffling between copies by recombination. Unlike autosomal haplotypes, there is effectively not any randomization of the Y-chromosome haplotype between generations. A human male should largely share the same Y chromosome as his father, give or take a few mutations; thus Y chromosomes tend to pass largely intact from father to son, with a small but accumulating number of mutations that can serve to differentiate male lineages.

Haplotypes in Y-DNA testing typically compare the results of Y-25, Y37, Y-67, or Y-111 STR tests. Table Two is an example of my haplotype for the Y-111 test. The haplotype basically represents the unique string of values for each of the STRs that compose the test. They number essentially do not mean much by themselves. They take on meaning when you compare them with other testers or pool my results with others to concoct dendrograms and higher level statistical analyses.

Table Two: Example of the Y-111 Haplotype for James Griffis

Y-111 Haplotype of James Griffis | **Click for Larger View.**

A modal haplotype is an ancestral haplotype derived from the DNA test results of a specific group of people, using genetic genealogy. Within each FTDNA work group that is based on haplogroups, surnames, geographical area, or other categories, typically test results are grouped on the basis of the most recent common ancestor that is based on a modal haplogroup. [9]

The modal haplotype is found on the third row of the table One. My results are found on the fourth row of the table for Kit number 851614. Click on the image for a viewable version. The table also provides the minimal allele values for each STR marker and the maximum allele values for each marker for comparison.

The ancestral haplotype is the haplotype of a most recent common ancestor (tMRCA) deduced by comparing descendants’ haplotypes and eliminating mutations. A minimum of three lines, as distantly related as possible, is recommended for deducing the ancestral haplotype. This process is known as triangulation. For FTDNA testing, ancestral haplotype basically refers to the haplotype of the tMost Recent Common Ancestor (tMRCA). In genetic genealogy, the Most Recent Common Ancestor (tMRCA) is the ancestor shared most recently between two individuals. [10]

For Y-DNA, the Most Recent Common Ancestor (tMRCA) is defined as the closest direct paternal ancestor that two males have in common . One of the questions all genealogists seek to answer is when a mutation occurs. We want to know when a mutation occurs and how closely we are related to others that have similar SNP or STR mutations. Unfortunately, that question, without traditional genealogical ancestral information, is very difficult to answer.

For the past two decades, many researchers have attempted to reliably answer that question. The key word here is ‘reliably’. The general consensus is that the occurrence of a SNP is someplace, on average, between 80 and roughly 140 years. The topic is hotly debated, and many factors can play into SNP age calculations. [11]

Since STRs mutate faster than SNPs and can also have a likelihood of mutating back to an original configuration, the estimate of the age of a STR mutation is challenging and depends on the specific STR since they each mutate at different rates. Given the nature STRs, the strategy for locating tMCRA with STRs relies on the concept of genetic generations (e.g. genetic distance). Translating genetic distance to years relies on statistical probabilities based on (a) the specific STR markers tested and (2) the number of STR markers used in calculations.

FTDNA Genetic Distance and Y-DNA STRs: Individual Matches

The main feature of FamilyTreeDNA’s Y-STR tests (Y-37 through Y-111) are finding Y-DNA matches. Like most DNA tests for genealogy, the test is most useful when compared to other people. The key question is, “When was the last common ancestor with this match?” When that is not obvious from comparing known genealogies, the genetic distance is the metric used to compare and estimate how far back in time the connection goes to identity the Most Recent Common Ancestor (tMRCA). Is the connection in recent times, just behind that genealogical brick wall, or in ancient, prehistoric times?

The FTDNATiP™ Report (TiP for Time Predictor) translates the Genetic Distance (GD) statistic into a time unit in predicted ‘years ago’. Depending on the average rate of mutation for sampled marker STRs, the number of differences between two samples (individuals) grows larger as the number of generations back to a common ancestor increases. FTDNA uses this idea to limit the number of matches shown in their match reports. As reflected in Table Three, if you have a 12 marker test (Y-12 STR test), their cut off is a genetic distance of one (one mutation difference), for their Y-37 marker tests the report cut off is at a genetical distance of 4, at 67 markers it is 7, and at 111 markers the report cut off is 10. [12]

Table Three: FTDNA Limits on Genetic Distance Based on Level of STR Test

Test Level	GD Limit for Matches
Y-12	0 or 1 if they are in the same working group project
Y-25	2
Y-37	4
Y-67	7
Y-111	10

In general, the closer the match in haplotypes between two individuals, the shorter the time back to a most recent common ancestor. For instance, if two individuals share the allele values for 35 out of 37 STR markers, they almost certainly share a more recent common ancestor than two individuals who share 25 out of 37 markers.

When it comes to calculating the genetic distance of a common ancestor, which STRs are different between the two individuals is more important that how many differences there are. This is due to the fact that STRs can behave differently from their expected mutation rates and because some STRs mutate faster than others. Regardless of whether one takes a 12 37, or 111 STR marker test, a distance of four matters more based on the mutation rates for each of the four markers that are different.

The following tables indicate the mutation rates for each of the STRs that are used for the various STR tests. [13]

Table Four: Mutation Rates for STRs 1 Through 37

STRs 1 through 37 | Click for Larger View

Table Five: Mutation Rates for STRs 38 – 67

Table Six: Mutation Rates for STRs 68 – 111

As mentioned earlier, calculating the Time to Most Recent Common Ancestor is based on probability and is not an exact science. We can identify the most likely time that a common ancestor might have lived, but there will always be a degree of uncertainly. It is better to think of “the Most Recent Common Ancestor” (tMRCA) as a range of time rather than a point in time. [14]

The following four charts show (noted by the dark line) the average number of generations that Y-DNA matches will share a common ancestor based on genetic distance. The statistical confidence levels are based large population samples and the two lighter lines show a band or range in which 95 percent of the matches will fall. The charts indicate where the FTDNA ‘cut off’ occurs. Notice that as you test more STR markers, the genetic distances also go up for the same number generations. For the Y chromosome these rates assume a 31 year generation and basing years ago from a 1955 “present date”. [15]

As illustrated in the following four illustrations, the statistical variabiability in determining the range of generations based on the concept of genetic distance can vary widely. Even comparing genetic distance with 111 STR test results, one will have a wide statistical variance. A genetic distance of 2 for a Y-111 comparison will mean that the match is within a 95 percent confidence interval of 2-10 generations. If a generation is around 31 years, then the match is equivalent to 62 – 320 years. Translating this range to ‘years before present would be 1955-62= 1893 CE and 1955-320= 1635 CE. That can be a wide range if you are looking for genetical matches. [16]

Illustration Two: Relationship of Genetic Distance to Generations at Y 12

Illustration Three: Relationship of Genetic Distance to Generations at Y37

Illustration Four: Relationship of Genetic Distance to Generations at Y67

Illustration Five: Relationship of Genetic Distance to Generations at Y111

Up until very recently, there were two methods to determine the GD.: the Step-Wise Mutation Model and the Infinite Allele Model. [17] In 2022, FTDNA released Age Estimates based on the Big Y-700 test. test results The millions of slow-mutating Y-SNP markers tested by Big Y together with the faster-mutating but fewer Y-STR markers derived revised the Time to Most Recent Common Ancestor (TMRCA) estimates of each branch on the Y-DNA haplotree. [18] Also in 2022, FTDNA updated FTDNATiP™ Report using Big Y haplotree TMRCA estimates from hundreds of thousands of pairs of Y-STR results from Big Y testers and built models to predict the most likely TMRCA ranges for each Y-STR marker level and genetic distance. [19]

Most mutations only cause a single repeat within a STR marker to be added or lost. For these markers, the Step-Wise Mutation Model is used. For example in Table Seven, comparing my results (Kit Number 851614) with Kit number 125476, who also lists a William Griffis as a Paternal Ancestor, the values of two STR markers differed by one value (see below), which means our GD is 2.

Table Seven: Comparison of Two STR Markers

Kit Number	DYS389ii Allele Value	DYS576 Allele Value
851614	28	18
125476	29	17

In some cases, an entire marker is added or deleted instead of a single repeat within a marker. This is believed to represent a single mutation in the same way that the addition or subtraction of a repeat is a single mutation event. For this reason, FTDNA uses the Infinite Allele Model in these cases. When an STR simply does not exist in an individual, this is called a null value. When a marker is missing, the value is listed as 0.

Multi-copy STR markers appear in more than one place on the Y chromosome. These are reported as the value found at each location, separated by hyphens. For example, in table one you may see DYS464= 12-13-13-13 or 12-12-13-13-13 or 12-13-13-13-13-13 . This means that the STR marker DYS464 has a unique number of repeats in each location. These locations are usually referred to as DYS464a, DYS464b, DYS464c, etc.

An example of this situation is illustrated in Table Eight by comparing my STR results in Table One (Kit Number 851614) with Kit Number 31454 (whose Paternal Ancestor is William Wamsley) and 285488 (whose self reported paternal ancestor was George Williams).:

Table Eight: Comparison of Multi-Copy STR Markers

Kit Number	DYS 464a	DYS 464b	DYS 464c	DYS 464d	DYS 464e	DYS 464f	Total GD
851614	12	13	13	13
31454	12	12	13	13	13		2
285488	12	13	13	13	13	13	2

Within multi-copy markers, there are two types of mutations, or changes, that can occur: marker changes and copy changes. Marker changes (changes in how many repeats are within a marker) are counted with the Step-Wise Mutation Model. Copy changes (changes in the number of markers, regardless of how many repeats are in each) are counted with the Infinite Allele Model.

In the example illustrated in Table Eight, if we compare Kit 31454 to my kit 851614, the allele value for DYS464b is different by one (marker change) and also 31454 has an additional copy (DYS464e), which totals to a genetic distance of 2. Comparing kit 285488 with my kit reveals no marker changes in DYS464a-d but two additional copy changes (DYS464e-f), which totals to a GD of two.

Adding together the GD for each marker in two people provides the overall GD for those two people. When a GD becomes ‘too great’, it is unlikely that the two people share a common ancestor within a ‘genealogical timeframe’, so FTDNA establishes a upper level limit for reporting matched based on GD.

Table Nine provides a practical example of FTDNA’s strategy of comparing the differences between haplotypes of individual test results based on similar haplogroups. I have listed the surname of each of the testers and the STR test they completed (re: Y-37, Y-67, Y-111, or Big Y 700 test. The table also provides information on the most recent haplogroup branch their respective tests were able to document. A Big Y 700 test provides results for 700 STR and therefore can provide the most granular test results for haplogroup designation. The table also indicates the self reported earliest known paternal ancestor for the tester.

Table Nine: STR Haplotype Matches with James Griffis Based on Y-37 Test

Kit No.	Surname	STR Markers Tested	Genetic Distance (GD)	Likely Common Ancestor (Genera- tons) [12]	MRCA Based on GD [12]	Earlest Known Ancester
125476	Griffith	37	2 Steps	8 (2-20)	1650 CE	William Griffis
39633	Compton	37	2 Steps	8 (2-20)	1650 CE	Unknown
154471	Williams	111	4 Steps	3(7-15)	1700 CE	William Williams
285488	Williams	700	4 Steps	3(7-15)	1700 CE	George Williams
294448	Williams	111	4 Steps	3(7-15)	1700 CE	George Williams
285458	Williams	111	4 Steps	3(7-15)	1700 CE	George Williams
36706	Williams	67	4 Steps	11(4-22)	1500 CE	William Williams
149885	Gough	37	4 Steps	14(6-28)	1300 CE	Gough

Source: FTDNA myFTDNA Y-DNA Match Results for James Griffis

As illustrated in Table Nine, although the tester whose last name is Griffith (first. row of the table) only tested for the Y-37 test, his test results are 2 steps different from my test results. If we look at Illustration Three above, this means I and Mr. Griffith share a common ancestor around 8 generations ago or between 2 to 20 generations.. Eight generations would be around the revolutionary war period.

There is another test kit that is 2 steps different from my test kit results. The test kit 39633, who has a surname of Compton appears to be as close as Mr. Griffith. I do not have any traditional genealogical documentation that references an individual with the last name of Compton. Rather than dismiss the results, one needs to look ‘outside the box’ in terms of critically analyzing the results. I may need to reach out to this gentleman to see what potential connections we might have. Also, based on the statistical confidence levels associated with the Y-32 STR tests, the MRCA may be as far back as 20 generations or 620 years ago which is around 1400 CE.

The remaining six testers are four steps different from my test results. While I know there are no individuals who are related in the past three generations, perhaps 15 to 22 generations back there might be a common ancestor. The outer range would be around 682 years ago or around 1340 CE. which would be before the use of surnames.

Based on the results, further research into the background of Mr. Griffith, whose earliest known ancestor was a ‘William Griffis from Hungton, NY” may lead to promising results! 12 generations would be around the early colonial era (1650). It may also be worthwhile to look into the Williams’ connections!

Phylogenetic Trees: Graphic View of Genetic Distance at the Lineage Level

In addition to analyzing and providing Y-DNA test results, FTDNA provides a wide platform of ways in which DNA results are analyzed and the results are packaged for consumers to identify possible genetic matches. There are also a number of analytical tools that have been developed by individuals that compliment or enhance the ability to assess genetic distance.

I can complement the second stage of an analysis by reviewing the results of genetic distance that we just discussed in a number of program generated mutation history trees. These types of programs give a pictorial representation of how the different members of a lineage may be related.

The branching pattern derived from the DNA mutations may very well correspond to the branching pattern that one might see in a traditional family history tree if we were able to trace it all the way back with documentary evidence to the MRCA (Most Recent Common Ancestor). The Mutation History Tree can give us important clues regarding which individuals are likely to be on the same branch of the overall tree, and who is more closely related to whom. This in turn can help focus further documentary research.

One type of mutation history tree has been developed by David Vance that uses FTDNA data that creates a Y-DNA phylogenetic tree. The program is relatively easy to use and graphically provides an intuitive approach to visualize the possible genetic relationships between various DNA test results. The program is referred to as the SAPP analysis (Still Another Phylogeny Program). The current version that was used in my analysis was SAPP Tree Generator V4.25. [20]

The program uses STRs from any of the STR tests (e.g., Y25, Y37, Y67, Y111), to construct a Y-DNA phylogenetic tree. It also has the ability to incorporate the SNPs found in BigY tests to fine-tune the genetic links and estimated times to the most common recent ancestor. The program can also incorporate known names and birth dates of ancestors to further fine-tune the analysis.

The program provides:

STR Table. This table is included to verify the STR input. It starts with the calculated Group Modal Haplotype for your input set followed by all the input kits with the off-modals colored.
Original Genetic Distance Table. This table calculates genetic distances (GDs) from the input STR results. It should match closely with GD calculations from other tools and commercial companies.
Adjusted Genetic Distance Table. This table re-calculates the GDs based on the tree that SAPP has just calculated. It will correct for any convergence that may have occurred in the calculated tree.
Kit to SNP/Genealogy Cross-Reference. This table summarizes the input SNP and Genealogy data showing the +. -. or ? status against the various kits.
The Image or Web version of the Tree File. The program creates a downloadable file containing the phylogenetic tree. Normally the tree is drawn as a graphic, as indicated in Illustration Six.

Illustration Six: Explanation of the SAPP Phylogenetic Tree

Utilizing the STR results, SNP data, and self reported paternal ancestor information for the 12 tests kits found in Table One, the following phylogenetic tree was created (click on the image of the thumbnail of the tree to be able to actually see the table). I have provided a PDF version of the Phylogenetic Chart which allows you to enlarge the image to get a better view.

Illustration Seven: Phylogenetic Tree Results for FTDNA STR Test Results for Individuals within the G-BY211678 Haplogroup (Click for Larger View)

The phylogenetic tree reveals three major genetic groupings of the 12 test kit results. One of those groupings tie my results (FTDNA Kit Number 851614) with an individual whose surname is Griffith (FTDNA Kit Number 285458) and claims the same paternal ancestor, William Griffis see Illustration Eight.

Illustration Eight: Close Up of Phylogenetic Tree

The following are the original and adjusted genetic distance tables generated by the SAPP program. The number of STRs tested are listed on the diagonal in blue. Cell colors refer to the number of STRs tested – cells of different colors are not directly comparable.
Red numbers indicate where adjusted genetic distances are different from original calculation.

Table Ten: SAPP Generated Original Genetic Distance between the 12 Test Kits.

Table Eleven : SAPP Generated Original Genetic Distance between the 12 Test Kits.

Based on the SAPP results, consistent with the FTDNA analysis, it is estimated that the most recent common ancestor between me and Mr. Griffith is approximately 8 generations or 248 years ago (estimating a generation to be 31 years) which would mean the MRCA was born around 1772. The birth date of William Griffis was 1736.

The results of the SAPP analysis suggests that there possibly may be an additional three haplotree branches, based on differences between STR haplotypes among the twelve test kits.

The phylogenetic chart indicates that the MRCA for all of the twelve test kits is estimated at 23 generations. The MRCA was born around 1500 CE for the G-BY211678 haplogroup. The Node #13 of which I and Mr. Griffith are representatives has the strongest connection in the tree. M=Test kits that indicates the ancestral person as William Williams or William Walmsley appear to have a MRCA 3 generations ago (born around 1850).

Genetic Distance at the Macro Level: Distance Dendrograms

The creation of dendrogram is another tool to use when analyzing STR data. Dendrograms can provide insights into macroscopic patterns in Y-DNA genetics and possible genetic matches of present day Y-DNA testers. The diagram based approach of a dendrogram is visually intriguing. Distance dendrograms are software-generated diagrams that convey relationships based on distance measured either in years or generations. Statistically, the dendrograpms used in the present context for genealogy are constructed by hierarchic clustering and the UPGMA method and are more focused on macroscopic genetic patterns. They complement other tools that focus on family level matches. [21]

Up until this point in the story we have discussed computing tMRCA based on the concept of genetic distance (GD). This sort of pairwise tMRCA analysis is subject to a signfiicant range of statistical uncertainty (as reflected in the above tables for generational distance).

A tMRCA can also be calculated between a single DNA tester and the estimate pattern of a chosen ancestor using a modal haplotype. If you have a large enough set of DNA test kits to sample, the ancestral haplotype will be close to that unknowable MRCA. However, this type of averaging still creates a wide level of variance for individual contemporary testers to compare their results with this ‘statistical archetype’.

The dendrograms generated in Rob Spencer’s model is based on a ‘whole-clade’ estimation of the MRCA. The MRCA for an entire clade (haplogroup branch) can be determined based on a common ancestor or a target SNP. The distribution of pairwise MRCA’s for a number of selected DNA kits in a given clade can be fit into a statistical curve fitting process (e.g. lognormal distribution). This curve fitting process is done on a specific group of DNA kits using statistical methods that are way above my pay grade. [22]

The scale of the data and graphics can reveal large scale, high-level patterns of when one person became the descendant of all others (single founder clades), patterns of descent from a single colonial founder in the America (typically one person is the descendant of all in America), and other demographic patterns that are not apparent using other methods of presenting DNA test results.

Dendrograms are ‘close cousins’ to family trees. The Y-STR Dendrogram is a diagram similar to a family tree. Individual DNA testers are the dots at the right (if the dendrogram is horizontal) or at the bottom (if the Dendrogram is vertical). Time moves backward to the left (if horizontally depicted) or down and up( vertically presented). On a traditional family tree, branch points are actual ancestors. In the dendrogram the branch points are generally not specific people but points in time when genetic mutations or changes occurred. In some cases, with good paper genealogy, branch points can be matched to specific ancestors. [23]

Looking at dendrograpm from another angle, they are graphic renderings of a statistical analysis which compares the differences of STR allele values between a group of DNA testers to determine the most recent common ancestors (tMRCA) between a group of testers. One of the key properties of a distance dendrogram is that if the input distances are accurate and consistent, then the graphic will completely and correctly represent a family tree. If we had a sufficient set of testers who had done DNA tests and tMRCAs could be calculated for all pairs with complete accuracy, then the dendrogram would be an accurate family tree.

You can demonstrate the relatiohsip between dendrograms and family trees for yourself with the Distance Tree Introduction interactive tool, and also for larger and more realistic family trees with the Family Simulator, both created by Rob Spencer.

The major limitation to the accuracy of the dendrogram trees is the statistical and random nature of STR mutations. In general, dendrograms constructed from Y12 or Y37 data will be reliable, while those built with Y111 or Big Y700 data data will be sufficient to see large-scale patterns (“macro genetics”) and in many cases can be close approximations to the true family tree. [24]

One important difference between a dendrogram and a family tree is that a dendrogram defines only the “leaf nodes”. A dendrogram does not “know” that there are other nodes that represent people on the diagram. The joining nodes or points are mathematical constructs. Every joining-point or “T” junction in the diagram corresponds to a specific genetic ancestor.

“(Dendograms) are very reliable for exclusion: you can say with very high confidence that two people are not related if there is a strong mismatch of their STR patterns. This is the forensic use of DNA: it’s very powerful in proving innocence while less decisive about proving guilt.” [25]

“Most of us use Y STR data locally to explore personal matches and to help in building family trees. But STRs can tell us much more when we sit back and take a long look. In this talk we use an efficient way to visualize thousands of kits at once. The large-scale patterns explain “convergence”, illuminate ancient, feudal, and colonial expansions, pick apart Scottish clans, identify American immigrant families, allow accurate relative clade dating, let us see the onset of surnames, and reveal the power law distribution of lineages.” [26]

Utilizing STR and SNP data, dendrograms can spot American Immigrant families based on the shape of the dendrogram. Typically there is a gap of 10 plus generations to the next ancestor and an expansion around 5-15 generations ago. [27] Similarly, the advent of surname usage can appear in dendrogram renditions of Y-DNA data. You should expect a common surname only for branches with a tMRCA 25-30 generations ago. Otherwise connections between branches with surnames are essentially random. [28]

Illustration Nine provides a dendrogram of the entire group of FTDNA test kits for the L-497 Haplogroup work group. It includes testers who have minimally completed a Y37 STR test. The L-497 subclade, of which the Griff(is)(es)(ith) paternal line is a part, genetically branched off around 8900 BCE, the man who is the most recent common ancestor of this line is estimated to have been born around 5300 BCE. There are about 1,760 FTDNA based DNA tested descendants, and they specified that their earliest known origins are from Germany, England, United States, and 53 other countries. I included the entire group of test results to show the general shape and patterns revealed in the dendrogram.

STR distance dendrograpms usually contain clear and distinct clades, which are sets of men with a common ancestor. Such clades are characterized by a curved top boundary. in the dendrogram. This is what gives the dendrogram its characteristic ‘slope shape’. If we had test results of all family members the dendrogram would be more square shaped and resemble a family tree. Since that is impossible, there are obviously gaps and the sloping tops for respective clades of the dendrogram is due to the statistical range of the STR mutations and the history of a given haplogroup. .

While the G haplogroup was one of the dominant lineages of Neolithic farmers and herders who as a second wave into Europe, migrated from Anatolia to Europe between 9,000 and 6,000 years ago, they were overtaken by the R Haplogroup as part of a third wave of human migration into Europe and are consequently are presently a minority genetic group in Europe. The male lineages represented by the G haplogroup line are diminished and this is represented in dendrograms with long thin lines through time representing fewer male descendants.

I have highlighted distinctive clades in Illustration Nine as well as indicating the relative position of two possible descendants of William Griffis. To get a better view of this long Dendrogram, I have included a PDF version which allows one to increase the magnification of the image.

Illustration Nine: Dendrogram of FTDNA Y37 to Big Y Test Results for Members of the L-497 D-DNA Group

Y-DNA Dendrogram: L-497 Work Group Y37 and up
**Click for larger View**

If we look a bit closer at the results that are roughly highlighted in Illustration Nine, we can still see the “slope of an approximately family genetic clade structure” for individuals that have a Williams surname. This is reflected in illustration 10. My line of patrilineal descendants have a MRCA with this Williams clade around 14 generations ago. This MRCA was born would be about 434 years before present or about 1488 CE.

Illustration Ten: Dendrogram of FTDNA Y37 – Big Y Test Results for Members of the L-497 D-DNA Group – Blow-Up Portion Where My Test Kit is Located

The dendrogram reinforced the connection with Mr. Griffith’s test kit. The dendrogram shows that we have a common ancestor about 8 generations ago. I highlighted our two kits in the dendrogram.

An alternative view of the dendrogram in Illustration Ten is provided by tightening the generational time scale, is provided in Illustration Eleven. It is the same data but the horizontal scale of the dendrogram has been shortened.

Illustration Eleven: Dendrogram of FTDNA Y37 – Big Y Test Results for Members of the L-497 D-DNA Group – Blow-Up Portion Where My Test Kit is Located, Shortened Time Horizontal the scale

Comparing the SAPP and dendrogram results with the Genetic Distance results reveal similarities. They both point to a genetic relationship with Kit 285458 (Griffith) with my Kit (285614). Both analyses point to a MRCA between our kits at 8 generations.

What’s Next

The next part of the story provides the results of corroborating a Griff(is)(es)(ith) relative, Henry Vieth Griffith, through the analysis of Y-DNA STRs!

Sources

Feature Image of the story is a dendrogram of comparing test kits results of Y-STR tests. Dendrograms are software-generated diagrams that convey relationships based on distance measured in generations. The dendrogram graphically portrays th genetic distance between individuals who are genetically related to me in the past 20 gnerations (e.g. the past 660 years). It is a graphic and mathematical confrmation of my conneection with Henry Vieth Griffith.

[1] Chang J (1999) Recent common ancestors of all present-day individuals. Advances in Applied Probability 31: 1002–1026.

Rohde DLT, Olson S, Chang JT (2004) Modelling the recent common ancestry of all living humans. Nature 431: 562–566.

Rohde DL, Olson S, Chang JT; Olson; Chang (September 2004). “Modelling the recent common ancestry of all living humans” (PDF). Nature. 431 (7008): 562–66. Bibcode:2004Natur.431..562R. CiteSeerX 10.1.1.78.8467. doi:10.1038/nature02842. PMID 15457259. S2CID 3563900

[2] Kevin P Donnelly, The probability that related individuals share some section of genome identical by descent. Theoretical Population Biology Vol 23: Issue 1, 1983, Pages 34–63. https://www.sciencedirect.com/science/article/pii/0040580983900047

[3] Rohde DLT, Olson S, Chang JT (2004) Modelling the recent common ancestry of all living humans. Nature 431: 562–566.

[4] John Hawks, When did humankind’s last common ancestor live? A surprisingly short time ago, 10 Jul 2022, John Hawks Weblog, https://johnhawks.net/weblog/when-did-humankinds-last-common-ancestor-live/

[5] Identical ancestors point , Wikipedia, This page was last edited on 17 December 2022, https://en.wikipedia.org/wiki/Identical_ancestors_point

[6] Genetic Distance, Wikipedia, This page was last updated 7 Dec 2022, https://en.wikipedia.org/wiki/Genetic_distance

Genetic distance, International Society of Genetic Genealology, Page was last updated 31 Jan 2017, https://isogg.org/wiki/Genetic_distance

Understanding Y-DNA Genetic Distance, FTDNA Help Center, https://help.familytreedna.com/hc/en-us/articles/6019925167631-Understanding-Y-DNA-Genetic-Distance

[7] The Most Recent Common Ancestor, International Society of Genetic Genealology Wiki, This page was last editd on 31 Jan 2017, https://isogg.org/wiki/Most_recent_common_ancestor

David Vance, Chapter 16, Estimating Ages to Common Ancestors, David Vance, The Genealogist Guide to Genetic Testing, 2020

[8] Haplotype, Wikipedia, This page was last edited on 11 February 2023, https://en.wikipedia.org/wiki/Haplotype

[9] Modal Haplotype, Wikipedia, This page was last edited on 6 April 2020, https://en.wikipedia.org/wiki/Modal_haplotype

[10] Ancestral Haplotype, International Society of Genetic Genealology Wiki, This page was last edited on 31 January 2017, https://isogg.org/wiki/Ancestral_haplotype

[11] Most Recent Common Ancestor, Glossary of Terms, FTDNA Help Center , https://help.familytreedna.com/hc/en-us/articles/4418230173967-Glossary-Terms-#m-0-12

Most recent common ancestor, International Society of Genetic Genealogy Wiki, page was last edited on 31 January 2017, https://isogg.org/wiki/Most_recent_common_ancestor

Most recent common ancestor, Wikipedia, page was last edited on 20 October 2022, https://en.wikipedia.org/wiki/Most_recent_common_ancestor

What is YFull’s subclade age methodology, page accessed 9 Aug 2022, https://www.yfull.com/faq/how-does-yfull-determine-formed-age-tmrca-and-ci/

The results and methodology used for determining ages from Big-Y SNPs can also be found in Iain McDonald’s U106 analysis. Read the PDF version at http://www.jb.man.ac.uk/~mcdonald/genetics.html which are updated several times a year.

Iain McDonald, Improved Models of Coalescence Ages of Y-DNA Haplogroups. Genes. 2021; 12(6):862. https://doi.org/10.3390/genes12060862

Poznik, G., Xue, Y., Mendez, F. et al. Punctuated bursts in human male demography inferred from 1,244 worldwide Y-chromosome sequences. Nat Genet 48, 593–599 (2016). https://doi.org/10.1038/ng.3559 for PDF version: https://pure.mpg.de/rest/items/item_2307728/component/file_2307727/content

Shigeki Nakagome, Gorka Alkorta-Aranburu, Roberto Amato, Bryan Howie, Benjamin M. Peter, Richard R. Hudson, Anna Di Rienzo, Estimating the Ages of Selection Signals from Different Epochs in Human History, Molecular Biology and Evolution, Volume 33, Issue 3, March 2016, Pages 657–669, https://doi.org/10.1093/molbev/msv256

Kun Wang, Mahashweta Basu, Justin Malin, Sridhar Hannenhalli, A transcription-centric model of SNP-Age interaction, PLOS Genetics doi: 10.1371/journal.pgen.1009427 , bioRxiv 2020.03.02.973388; doi: https://doi.org/10.1101/2020.03.02.973388

Zhou, J., Teo, YY. Estimating time to the most recent common ancestor (TMRCA): comparison and application of eight methods. Eur J Hum Genet 24, 1195–1201 (2016). https://doi.org/10.1038/ejhg.2015.258.

Most recent common ancestor, International Society of Genetic Genealogy Wiki, page was last edited on 31 January 2017, https://isogg.org/wiki/Most_recent_common_ancestor

Most recent common ancestor, Wikipedia, page was last edited on 20 October 2022, https://en.wikipedia.org/wiki/Most_recent_common_ancestor

For specific information on history of the haplotree and related nomenclature, see also: International Society of Genetic Genealogy, Y-DNA Haplogrouptree 2019 – 2020, Version: 15.73 Date: 11 July 2020, https://isogg.org/tree/

YFull has a documented system to estimate SNP ages. This is how to get their estimate:

Go to YFull’s SNP search page; 2) Enter a SNP name and click the Search button; 3) A green hyperlink, labeled with a haplotree branch name (e.g., “R-L47”), should be displayed. Click on it; 4) You should now see a branch of the haplotree. Typically, this branch will have two dates: (a) The “formed” date is an estimate of when this branch began to diverge from its surviving siblings. (Extinct siblings are unknowable and therefore ignored.) (b) The “TMRCA” date is an estimate of when this branch’s surviving children began to diverge from each other. (Again, extinct lineages are ignored.)

[12] The GD estimates and estimated number of Generations is based on FTDNATiP™ Reports, Most Recent Common Ancestor Time Predictor based on Y-STR Genetic Distance

Understanding Y-DNA Genetic Distance, FTDNA Help Center, https://help.familytreedna.com/hc/en-us/articles/6019925167631-Understanding-Y-DNA-Genetic-Distance

Concepts – Genetic Distance, DNAeXplained – Genetic Genealogy,, Blog, 29 June 2016, https://dna-explained.com/2016/06/29/concepts-genetic-distance/

[13] J David Vance, The Genealogist Guide to Genetic Testing, 2020 , Chapter 5, https://www.amazon.com/Genealogists-Guide-Testing-Genetic-Genealogy/dp/B085HQXF4Z/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=&sr=

[14] Ibid.

[15] These illustrations of the relationship between genetic distance and generations are from: David Vance, The Genealogist Guide to Genetic Testing, 2020 , Chapter 5

The statistical analyses were based on:

J. Douglas McDonald, TMRCA Calculator, Oct 2014 version, Clan Donald, USA website, Https://clandonaldusa.org/index.php/tmrca-calculator

[16] “For the Y chromosome these rates assume a 31 year generation.”

J. Douglas McDonald, TMRCA Calculator, Oct 2014 version, Clan Donald, USA website, Https://clandonaldusa.org/index.php/tmrca-calculator

[17] “The original FTDNATiP™ Report was based on research by Bruce Walsh, Professor at the University of Arizona, and his 2001 paper in Genetics. Walsh used a theoretical approach to model STR mutation rates and estimate when two people’s’ paths diverged in the Y-DNA haplotree. He used an infinite allele model, which theoretically accounts for markers mutating more than once, which can obscure the true mutation rate.”

Introducing the New FTDNATiP™ Report for Y-STRs, FTDNA Blog, 16 Feb 2023, https://blog.familytreedna.com/ftdnatip-report/

[18] Big Y Age Estimates: Updates and the Battle of Falkirk, FTDNA Blog, 9 Sep 2022, https://blog.familytreedna.com/tmrca-age-estimates-update/

Phylogenetic age estimation, otherwise known as “divergence dating,” has a long and rich history that began in the 1960s. Two general classes of methods have emerged: a strict molecular clock, and a relaxed clock. Sep 19, 2022, FTDNA Blog, https://blog.familytreedna.com/tmrca-age-estimates-scientific-details/

The Group Time Tree: A New Big Y Tool for FamilyTreeDNA Group Projects, FamilyTreeDNA Blog, 15 Feb 2023, https://blog.familytreedna.com/group-time-tree/

[19] Introducing the New FTDNATiP™ Report for Y-STRs, FTDNA Blog, 16 Feb 2023, https://blog.familytreedna.com/ftdnatip-report/

[20] David Vance, The Life of Trees (Or: Still Another Phylogeny Program),SAPP Tree Generator V4.25, http://www.jdvsite.com

Dave Vance, Y-DNA Phylogeny Reconstruction using likelihood-weighted phenetic and cladistic data – the SAPP Program, 2019, academia.edu, https://www.academia.edu/38515225/Y-DNA_Phylogeny_Reconstruction_using_likelihood-weighted_phenetic_and_cladistic_data_-_the_SAPP_Program

Y-DNA tools, International Society of Genetic Genealology Wiki, This page was last edited on 30 June 2022, https://isogg.org/wiki/Y-DNA_tools

Sennet Family Tree Blog, The SAPP is up and running: a phylogenetic analysis of Sennett surname project members, 8 May 2021, https://sennettfamilytree.wordpress.com/2021/05/08/the-sapp-is-up-and-running-a-phylogenetic-analysis-of-sennett-surname-project-members/

[21] Introduction to Distance Dendrograms, Tracking Back: A Website for Genetic Genealology Tools, experimentation, and discussion, http://scaledinnovation.com/gg/gg.html?rr=ddintro

Michael Drout and Leah Smith, How to read a Dedrogram, Wheaton college, https://wheatoncollege.edu/wp-content/uploads/2012/08/How-to-Read-a-Dendrogram-Web-Ready.pdf

Tim Bock, What is a Dendrogram, DisplayR blog, no date, https://www.displayr.com/what-is-dendrogram/

Dendrograpm, Wikipedia, page was last edited on 7 September 2022 , https://en.wikipedia.org/wiki/Dendrogram

Prasad Pai Hierarchical clustering explained, Towards Data Science, 7 May 2021, https://towardsdatascience.com/hierarchical-clustering-explained-e59b13846da8

Tom Tullis, Bill Albert, Hierarchical Cluster Analysis, in Measuring the User Experience (Second Edition), 2013 https://www.sciencedirect.com/topics/computer-science/hierarchical-cluster-analysis

Rob Spencer, Simple Distance Tree, Tracking Back – a website for genetic genealogy tools, experimentation, and discussion, 2023-01-28, ,http://scaledinnovation.com/gg/treeDemo.html

Rob Spencer, Family Tree and Y-DNA Simulator, Tracking Back – a website for genetic genealogy tools, experimentation, and discussion, http://scaledinnovation.com/gg/familySimulator.html

[22] Rob Spencer, Y STR Clustering and Dendrogram Drawing, Click on Discussion Tab, Tracking Back Click – a website for genetic genealogy tools, experimentation, and discussion, http://scaledinnovation.com/gg/clustering.html

[23] Introduction to Distance Dendrograms, Tracking Back: A Website for Genetic Genealology Tools, experimentation, and discussion, http://scaledinnovation.com/gg/gg.html?rr=ddintro

[24] Rob Spencer, The Big Picture of Y STR Patterns, The 14th International Conference on Genetic Genealogy, Houston, TX March 22-24, 2019, http://scaledinnovation.com/gg/ext/RWS-Houston-2019-WideAngleView.pdf Page 28

[25].Rob Spencer, Introduction to Distance Dendrograms, Tracking Back: A Website for Genetic Genealology Tools, experimentation, and discussion, http://scaledinnovation.com/gg/gg.html?rr=ddintro

[26] Rob Spencer, The Big Picture of Y STR Patterns, The 14th International Conference on Genetic Genealogy, Houston, TX March 22-24, 2019, http://scaledinnovation.com/gg/ext/RWS-Houston-2019-WideAngleView.pdf

[27] Rob Spencer, The Big Picture of Y STR Patterns, The 14th International Conference on Genetic Genealogy, Houston, TX March 22-24, 2019, http://scaledinnovation.com/gg/ext/RWS-Houston-2019-WideAngleView.pdf Page 12

Source: Rob Spencer **Click for Larger View**

[28] Rob Spencer, The Big Picture of Y STR Patterns, The 14th International Conference on Genetic Genealogy, Houston, TX March 22-24, 2019, http://scaledinnovation.com/gg/ext/RWS-Houston-2019-WideAngleView.pdf Page 11