This article was posted today, July 13, 2018 by Maurice Gleeson, Organizer of Genetic Genealogy Ireland, in his blog “DNA and Family Tree Research”. It is re-posted here with his permission.
Goodbye NPE, Hello SDS – some causes of Surname or DNA Switches
- According to several different studies, the average incidence of SDSs seems to be about 1-2% per generation.
- So, if we allow 25 years per generation and hence 4 generations in 100 yrs, that will give us 40 generations in 1000 years.
- multiply that by 1-2% per generation and that gives us a 33-55% chance of an SDS on any ancestral line going back 40 generations [for these corrected calculations see the first comment in the Comments section below]
- If we go back along the father’s father’s father’s line, then there is a 33-55% chance that your Y-DNA does not go back to the person who originated that surname.
- If we allow 33 years per generation (and hence 3 generations per 100 years), then the chances of an SDS in the past 1000 years is 28-49% on each ancestral line [for these corrected calculations see the first comment in the Comments section below]
- Whether you choose the 33-55% option or the 28-49% option, about half of us will not share the same DNA as the man who first held our surname … but half of us will.
There are many causes for SDSs and in relation to Irish family history, there are some unusual Irish-specific reasons for SDSs.
|The Past was a different country – different customs, different reasons for Surname or DNA Switches (SDS)|
A similar situation arose with the Trans-Atlantic Slave Trade, where many enslaved people were given the surname of the Plantation Owner. Thus many African Americans today will carry the name of the slave owner of their ancestors (i.e. SDS present), and some will carry the Y-DNA of that slave owner (i.e. no SDS present), or his family (possible SDS), or the overseers he employed on his plantation (SDS present).
Adoption / Fostering / Guardianship
Modern adoptions are an obvious cause of surname switches. The adopted child takes on the surname of the adoptive father but carries the Y-DNA of his birth father. In times past, orphans or waifs would take on the surname of their guardians. These examples result in the child-rearing father having a son with the same surname as himself but with different Y-DNA.
Fostering on the other hand, did not frequently result in a surname switch. Under the Brehon Law of fosterage, children were brought up by relatives who were usually within the 5th degree of kinship (e.g. great uncle, 1st cousin once removed). However, the child did not adopt the family name of his foster family. Instead he retained his own family name and thus there would have been no SDS as a result.
Similarly, with modern-day fostering, the child in question does not usually take on the name of the foster family i.e. there is no SDS.
Sometimes it was stipulated that a man would have to change his name in order to marry the daughter of a wealthy man to ensure that the family name was carried on. A good example is the Pennington family of Muncaster. There are two recent generations where the husband had to change his surname to Pennington as a condition of marriage. Thus, there have been two successive switches in the DNA associated with the Pennington surname along the same direct male line of descent.
A similar condition arises where the prospective heir has to change his name as a condition of inheritance – “You won’t inherit a penny, my boy, unless you change your surname to Sidebottom”.
|“Sidebottom, grandfather? … Seriously?!”|
Taking wife’s name upon marriage (because of her higher social status)
Morgan Williams and Katherine Cromwell’s eldest son Richard had two sons, Henry and Francis, both of whom also used the surname Cromwell. Henry was knighted and one of the youngest of his eleven children (Robert) was Oliver’s father.
Thus the Cromwell surname became associated with Williams DNA.
In ancient Irish culture, apparently it was customary to offer one’s wife to visiting dignitaries for “entertainment”. The custom is still practiced in certain cultures today. Thus the dignitary’s Y-DNA would become associated with any offspring of the union, but the child could be raised with the surname of the woman’s husband.
Why was such a custom practiced? A child by a powerful man would give protection to a family and also had rights to succession under Brehon Law. A good example is that of Mathew (Fear Dorcha) O’Neill(1520-1558), the illegitimate son of Conn O’Neill. He was accepted by Conn as his natural son and was made his heir. However, Shane (Mathew’s half-brother) contested his right of inheritance and Shane’s men eventually killed Mathew, but not before Mathew had a son, Hugh O’Neill, who later went on to become The Great Earl and Clan Chief of the O’Neill. On this occasion the Y-DNA and surname remained intact (no SDS) but in other cases, the surname of the father who reared the dignitary’s child may have been retained (i.e. SDS present).
There was also an associated custom of “Naming” children on a wife’s deathbed (i.e. she would reveal which of her children were the offspring of famous people). Apparently, as she lay dying, the wife would call her husband into the bedroom and something like the following conversation would ensue:
WIFE: Husband dear, I need to have a word with you.
HUSBAND: My dearest wife, what do you want?
WIFE: Well … you know our eldest child?
HUSBAND: Of course I do … sure isn’t he my son?!
WIFE: Well … that’s what I want to talk to you about …
There was a completely different concept of illegitimacy under Brehon Law and it was not unusual for men to have concubines. In addition, sex with servants was commonplace.
There was also apparently a custom whereby a woman could decide which man she wanted to sire her child and which she wanted to raise him. So Dim Dave may have been in demand for his awesome good looks, whilst Four-Eyed Stan was lumped with child-rearing because he was an excellent Dad (despite the limp and halitosis).
In more recent times, and certainly since the introduction of Victorian morality, the illegitimate offspring of any “out of wedlock” encounter would usually be given the maiden name of the mother. However, this was not always the case and I have seen illegitimate children christened with their biological father’s surname (in which case, no SDS is present).
|Girl Power under Brehon Law|
Anglicisation of surname
It was common for surnames to be anglicised in Ireland. And as a result there are some unlikely genetic associations between different surnames. The surname Green was at times an anglicised version of Hooney or Fahy, both of which are derived for an Irish word for the colour green.
Surname change to match the prevailing social circumstances
Sometimes people would change their name to suit their circumstances. A lot of Jewish immigrants to the US changed their name to make it sound more “English” and thus avoid discrimination. Similarly Catholics living in a predominantly Protestant community might change their name to “fit in”.
There is a popular belief that a lot of surnames were misspelt or assigned as people entered the US via Ellis Island but this has been contested for a variety of reasons. Firstly, passenger lists were not created in Ellis Island but at the port of departure of the immigrant i.e. in his or her native country, probably by a native speaker of the immigrant’s language. The inspector at Ellis Island did not write down the immigrant’s name – he worked from the passenger list.
Abandonment by husband
Some people changed the family’s name to reflect the family’s ambition to achieve higher social status.
More modern causes
In more modern times, the nature of SDSs is subtly changing with the introduction of new causes such as surrogacy, sperm donation, mitochondrial donation, and three parent families (one parent donates the egg, another the sperm, and a third the mitochondria).
This is not an exhaustive list of the causes of Surname or DNA Switches, so if you can think of other examples (and I am sure there will be many), please leave a comment below.
But hopefully it will be abundantly clear from the above, why you only have a roughly 50:50 chance that your Y-DNA goes all the way back to the person who originated your surname some 1000 years ago (or thereabouts). And why, as you go back along each ancestral line in your family tree, there are likely to be 3-parent and 4-parent families. In other words, one particular family may consist of a genetic father as well as a genealogical one. And some families (e.g. where an adoption has taken place) will consist of two genetic parents and two genealogical parents.
As a result, we all have two types of family tree superimposed on each other – one purely genetic, one purely genealogical. But both equally valid in terms of our family history. Both types of ancestor (genetic & genealogical) have contributed to who their offspring became … and who we are today.
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