Different Families or Different Branches?

As more men are taking DNA test-- both in the Slaven project and in the world at large-- we can infer more about our ancestry. Newer results have shed some light on the question whether Slaven DNA Project Groups A and B have a common "Sléibhín" ancestor, and whether the individual marked as "Group AB"in the extended results test page might represent a bridge between the two groups.

Since this analysis/webpage was originally done in 2009, newer and more detailed Y-DNA tests have come available. The Big Y-700 test at FamilyTreeDNA shows that there's no question about it-- the William Slaven line of North Carolina (Group A) and the John Slaven line of County Tyrone/Highland County, Virginia (Group B) are NOT related in a genealogical time frame. The most recent male line ancestor common to both lines was born about 1,900 years ago, centuries before surnames came into use.

Since there's no connection between the two lines for so many centuries, then the "Group AB" that was postulated as a possible bridge between the groups cannot be. This man's family line may still be connected to either Group A or Group B, but several centuries ago; if his test was upgraded to Big Y-700 it would be easy to tell. Or his family line too may just have adopted the surname coincidentally.

Like many family lines in Ireland, Northern Ireland, and Scotland, Groups A, B, and AB have the mutation that places them in the R-M222 haplogroup, which in the first decade of the 21st century got a lot of press as being the "Niall of the Nine Hostages" haplogroup. The R-M222 population grew dramatically in northwest Ireland and southwest Scotland in the first few centuries of the Common Era, tying in with the legends of Niall and his descendants, the Uí Néill. It's now known that the R-M222 mutation occurred several centuries before Niall. But it's still a handy placeholder in time, which we'll use in an explanation below.

Surnames develop in Ireland

Surname usage started to develop in Irealnd over a thousand years ago, with many families acquiring true surnames by the 11th century. There are two scenarios to account for how family lines with the same surname are related; they are diagrammed out here. The diagrams are certainly not drawn to any kind of a time scale, but simply illustrate in a more graphic way the two ideas.



The first idea is that the families' common ancestor lived before surnames were adopted, and an early ancestor of each of our three groups just happened to choose Sléibhín as their family name. So it's coincidence that the family groups chose the same surname; there undoubtedly are family lines that adopted other surnames and are as closely related to both Groups A and B. In other words, some random Connelly might be as closely related and just adopted a different surname.

This concept is illustrated at the right.

The other idea is that family groups have a common ancestor after the surname was adopted. Depending on the number of Y-DNA mutations between the family lines, this ancestor may have to have lived much closer to the time of surname adoption a thousand years ago than to the current day.

This idea is represented in the diagram to the left.

(And there's a third option, or course, where some of the groups have a common Sléibhín ancestor but another group arrived at the surname separately.) See the diagram to the right.
Since we're talking about possible relatedness in the 1,000-year time frame of surnames, there's little chance that connections between families can ever be proven through traditional genealogy. As anyone who's worked with Irish records knows, it's tough just getting back to the 19th century! But if the Sléibhín surname dates back a thousand years as The Annals of the Four Masters and other old texts state, then there has been plenty of time for multiple lines to have branched off. The Big Y-700 test from FamilyTreeDNA would, in most cases, answer whether groups of Slaven/Slavin/Slevin/etc. are related within the era of surnames.

Copyright © 2023 Larry Slavens. All rights reserved.