Non-Paternity Events: genetic diversity in the family

We can often use Y-DNA to follow the fatherline, because the Y chromosome is passed intact from father to son, in contrast to the autosomal chromosomes that pair up and swap material during reproduction. But not all males of a family have the same Y-chromosome because of adoptions of various kinds, technically called non-paternity events. This introduces some genetic diversity in a family. Thus, we can use Y DNA to trace ancestry in  a patrilineal society, but not to define families.

“A non-paternity event  is any event which has caused a break in the link between a hereditary surname and the Y-chromosome resulting in a son using a different surname from that of his biological father.”  (source) They happen most commonly when children are adopted into a family, either from an illegitimate child or a child from a previous marriage, but it can also happen when family names are changed in official documents. In some cases among the Lobbans the name changed happened early and we know of the connection only by luck with records, for example the two Logan lines and the Laban line. There are probably many more that we do not know about.

Whenever one family gains a Y-chromosome in this way, the other effectively family loses those descendants. However, I have counted these lines as part of the Lobban family because they still have a Lobban Y chromosome; they can claim the lineage as well as their family name, even though the family name has been different for centuries.  

Inbound NPEs

Below we describe two different examples of people adopting the Lobban name, the second one recently supported with Y-DNA evidence.

Alexander “Ross” Lobban (1850–1921)  (Tree.) was baptized as Alexander Ross, the illegitimate son of Hellen Stephen and Alexander Ross of Kirkton, Deskford, and he appears in the 1861 Census as the stepson of Hellen and Alexander Lobban. He changed his name to Lobban sometime between then and the 1871 Census. He married Jessie Mellis Thompson in 1876, with whom he had 5 boys and 3 girls, and also had an illegitimate daughter with Jessie Gibb about 1870.

Alexander Ross Lobban tree


Alexander “Harper” Lobban (1867–1949) (Tree.) was born to Ann Harper in Cairnie and the birth registration (available online) shows Alexander Lobban (1842–1916) as the father. Alex denied paternity but  Ann Harper took it to court and convinced the judge to add him as father. The original birth certificate listed no father,  but is annotated on the back with the court decision.  Alex-1842 left for Durham, England, where he met and married Isabella Smith, with whom he had many children.  Within the family arising from Alexander Lobban, who married Margaret Milne, there is a rumor that the child was actually the result of Ann’s affair with “the Laird o’ Glass,” and one of his descendants took the DF89 test to see if he was in the JFS0275 haplogroup. Answer: negative. This strongly suggests that indeed Alex Lobban-1842 was not the father.*


The question of Ann Harper’s mate.


* Further evidence to pin down the NPE may come from a tester in the Loanend line, whose most recent common ancestor with Ann Harper’s descendant is one generation back, and is expected to be JFS0275.  But proof positive would require showing some descendant of Alexander and Isabella Smith IS JFS0275.

Outbound NPEs

Besides many instances where a boy with a Lobban Y-chromosome was given the name of his adoptive family, there are  a few known instances of administrative name changes where a Loban family became Logan (see the Loban to Logan story and notes about George Logan on the Emigrants to USA page). Of course, even though they are Logan family, the descendants still carry the Loban Y-chromosome.  Two have tested Y-500 and one is in JFS0275 (which is why we’re even in The Logan Project).

The ultimate NPEs

Of course, the origin hypotheses for the name Loban /Lobban both involve someone (with another name) having adopted the name — i.e, a non-paternity event — so that if these stories are true, none of us is genetically a Lobban.

In the final analysis, NPEs could only occur once surnames came into use, and this began in Scotland about the 1300s, but didn’t begin to be used with any sort of consistency until the 1500s. (See Scottish-at-Heart page and our notes on role of the Little Ice Age in promoting use of surnames.)  As Scottish-at-Heart says, “If you’re interested in tracing your Scottish ancestors and think that your last name is going to play a central role in that quest – well, you can see how that may not be true!”   Since the time period when the name seems to have originated coincides with the time when surnames were neither universal nor consistently spelled, this makes it likely that there are several to many Y-DNA genotypes within the Scottish family Lobban/Loban, which can never be resolved from records.

So the bottom line to me is, if you are a Lobban or Loban with roots in Scotland* this is your family, regardless of what origins and NPEs we may be able to determine from records or DNA. The corollary, following biological practice, is that I consider all descendants of folks who were Loban/Lobban are also still part of the family, even if their family name changed: they can still claim Lobban ancestry.

* I have defined this project with the qualifier “with roots in Scotland” because Loban for sure and perhaps Lobban have also sprung up de novo in other countries — see our Frequency & Distribution page — and there is no reason to consider them related. This definition also excludes the Jamaican Lobbans until or unless some can show a genetic connection; their roots are clearly African.


Page by Christopher S. Lobban, 24 Dec. 2018, last revised 26 Dec.