INTRODUCTION TO GRIERSON DNA RESEARCH
J. David Grierson

This article was written by John David Grierson, known in the family as John (6), the 5th generation descendant of John Grierson who was born 1778 at Parton, Scotland, and who died in Australia in 1855. It includes material dating from 2005. It is a work in progress, and may be amended as the research progresses.

During 2002 I became interested in DNA testing (particularly YDNA) as an aid to conventional genealogy. The interest arose from the "brick wall" that seemed to have arisen in the search for Grierson ancestors, when it became apparent that the limit to easily accessible documentation had been reached. By 2003 I was well into the testing regime, and in a position to begin to draw conclusions from the study, albeit those conclusions were somewhat tentative because it was also apparent that the science was evolving rapidly, as it continues to do. Those early conclusions can now be seen to lack definition by comparison with more recent results, and doubtless there will be future advances that clarify things further. YDNA is that portion of the DNA transmitted only by a male at the time of conception. These notes are mainly directed at YDNA analysis, but much of the terminology is also applicable to mitochondrial DNA passed down by the female line.

At that time, analysis of Short Tandem Repeat (STR) strings was the available system to determine relationships. An STR is a microsatellite on the human genome which may repeat numbers of times, and these repeats can be different in different men. However, during the recent 18 years of development of the science as applied to genealogy, particularly in the hands of enthusiastic amateurs, we have seen that a better way to define male ancestry (that is, the YDNA trail) is to establish the youngest Single Nucleotide Polymorphism (SNP) carried in the YDNA. An SNP is a specific combination of proteins at a particular position on the human genome.   One issue has been the greater expense of testing for SNPs over that for testing STRs, but advances in technology have made SNP testing more affordable. [The reader is advised to explore the meanings of STR, SNP and microsatellite in Wikipedia.]

 For clarity, we now need to look at some more technical detail. A haplogroup defines a body of men who carry the same SNP mutation. During the period, as it became possible to test for haplogroups (as distinct from estimating them) we began to see more clustering of men, both within a surname group, and in the broader community. SNP mutations are very rare, and we presume that once they have happened, they are never reversed, certainly within the recent tens of thousands of years. So when a mutation has occurred during the conception of a male, it is assumed that all his descendant males will exactly match his SNP haplogroup or if there has been a further mutation, one of its sub-clades - he is the father of a tribe, so to speak.

 The classification of haplogroups has developed with the increase in knowledge. By international agreement, the principle divisions are labelled with a letter of the alphabet roughly corresponding to the age of the subdivision, so we see haplogroup A as representing those whose ancestry has changed little over the thousands of years of humanity. It is rare because many in the line died out without issue, and many mutations have occurred in the thousands, if not millions of years involved. For our purposes we should note that haplogroups I (probably mostly seen in those with northern European ancestry) and R (mostly seen in those with western European ancestry) are the major haplogroups of interest. The next step was to divide a haplogroup into “clades”, so when different mutations within R appeared they became R1 and R2. The next change would be reflected by R1a and R1b, and so on. For a number of years, the International Society of Genetic Genealogy (ISOGG) standardised a nomenclature which used alternate numbers and letters to identify SNPs, for example, R1b1c7 being a sequence that described a younger SNP underneath R1, and early on was the code for the R-M222 SNP.

 The problem that then arose was that, with the rapid advance in the testing, many younger SNPs were being identified, and descriptions such as R1b1b2a1a2f2 (which R1b1c7 had become in two years) were becoming cumbersome, so many (and now most) genealogists changed their practice to that of identifying SNPs by their commercial title, that is the name given by the company that first identified them. So we see FGCxxxx (being an SNP discovered by Full Genomes Corporation), or BYxxxx, one discovered by Family Tree during their “Big Y” program. There are possibly ten companies testing, so there are quite a range of prefixes to be seen.

 The terms “clade” and “haplogroup” are often used interchangeably we find now. From my point of view, the haplogroup that matters is the youngest SNP identified in more than one man, but we also need to know where that SNP sprang from.  

THE DEEPER ANCESTRY

The name Grierson (the modern spelling) is a South West Scottish surname, first noticed in extant documentation (as Greresoun and Greresone) in the early years of the 15th Century (ie, son of Grere as distinct from Gregor, although that might be a function of Gaelic pronunciation) . It appears in a charter relating to the sale of land in the Nith valley in the area then known as Galloway (being the Stewartry of Kirkcudbright, Wigtownshire, and parts of modern Dumfriesshire and Ayrshire). This deed addressed the change of ownership of an estate known as "Lag", and described the sale of the property by John McRath of Laught to Gilbert Grierson of Arde. The Griersons of Arde appear to have been hereditary bailies of the barony of Tibbers in the fourteenth century and by the end of the century, they were armigers. The sale was confirmed by Henry, Earl of Orkney, Lord of the valley of Nith on December 6, 1408. Lag was clearly a superior estate to Arde, and so Gilbert and his heritors have maintained the appellation "of Lag" since then. A seal affixed to a 1418 document states "Gilbert, son of Duncan". (There is reason to believe that this Duncan is the one mentioned in the mid-14th Century in Galloway.) George Dunbar, Earl of Dunbar and March was Gilbert’s feudal superior at the time of the purchase of Lag. During the next four hundred years, the family prospered, and ultimately became owners or, in the case of some cadet branches, kindly tenants, over very large tracts of land in the south of Scotland. In 1685 the Laird of Lag was made Baronet. By the 18th Century the name had spread widely throughout Galloway and Dumfriesshire.

At various times, but principally in the 16th and 17th Centuries, the name Grier was used as a form of shorthand. There are numerous documents and legal reports of the era in which the same man is referred to by both Grierson and Grier. In a descent chart (the Carrickfergus tree) produced under the sponsorship of Thomas Greer of Sea Park, Carrickfergus, Ireland, a High Sheriff and Member of Parliament in the latter part of the 19th Century, during the early 17th Century a branch descending from a brother of the then Laird of Lag is said to have migrated to Ireland, at the same time changing the preferred spelling from Grier to Greer. Oral tradition has it that another son of that branch migrated to North America at or about the same time, and his presumed descendants also use Greer. Later, some of the Irish Greers also emigrated, to North America. Greer appears only rarely in Scottish records.

There are family legends and clan legends, and there is also deliberate misinformation about Grierson origins. Were we MacGregors? Are we Irish? How do we take the next step in identifying our forefathers? The answer may well be in recent advances in the study of DNA, as passed from father to son.

 The link below is to The DNA Journey which describes the process by which I arrived at my conclusions. Appendix 1 is a demonstration of how a specific combination of STRs gave David Wilson the idea that a new SNP might exist, and also of how a modal exists. Appendix 2 shows how I extended Wilson’s idea leading to the identification to several new SNPs, and how STR analysis can be used to identify families.

 This has been updated 8 August 2020.


THE DNA JOURNEY

APPENDIX 1

APPENDIX 2

Last modified 30 Aug 2020