First Look at the Big Y-700.

I've been learning about the FamilyTreeDNA Big Y-700 test, and FTDNA just released some beta tools that are a big help.

So far, Slaven DNA project members who have upgraded their tests to the Big Y-700 are a descendant of John Slavin of Garrard County, Kentucky, of Richard Harve Slaven of Kentucky/Tennessee, of Samuel Slaven of Georgia/Indiana, and of John Slaven of Highland County, Virginia. The first three mentioned are all believed to be descended from William Slaven (Slavin, Esleven, Asleven, etc.) of Rowan County, North Carolina.

What is the Big-Y test?

Men who take STR tests alone, meaning 12-111 markers only, receive STR matching and an estimated haplogroup. A haplogroup is named for the DNA mutation that defines it (i.e. R-M222) and defines a branch on the genetic tree. The haplogroup at this level of testing is broad, dataing back hundreds to thousands of years.

Men who take the Big Y test receive STR results and matches (for the original 12-111 markers). They also receive the most refined haplogroup possible, usually only a few hundred years old to as recent as a few generations. They also receive the results for many additional STR markers (over 700 total), their SNP matches, and placement and a couple different graphical representations of where their haplogroup sits in relation to others.

The Big-Y test analyzes so much of the Y-chromosome that it's fairly family-specific... IF enough related men take the Big-Y test. Each person tested is going to have a number of SNP mutations that aren't shared with others in the database. One (rarely more) of these private SNPs or private variants, as they're also called, may have occurred with the tester, but most occurred in previous generations. From discussions on Big-Y Facebook groups, a rule of thumb is one private variant every two or three generations. But being random events, it's possible to have two or more in a single generation, to have new private variants in two or more consecutive generations, or to go more than three generations without a private variant.

FamilyTreeDNA will add a new haplogroup to the public tree and databases when two or more testers have the same previously private variant. So, as an example, if John of Garrard has a mutation that brothers William and Robert don't have, a new haplogroup will be established when a second descendant of John's tests.

What have we found so far?

The William Slaven descendants are very close matches, as would be expected. They share three variants— three SNP mutations— that according to FTDNA, show "a paternal lineage of father-son relationships that have accumulated mutations over time." They have been assigned their own haplogroup, R-FTB71305; the most recent common ancestor for the haplogroup is calculated to be between 1381 - 1899, with the statistical mean (the average) being 1708. Depending on the source/family tree, William Slaven's birth is between 1711 and 1720— pretty much dead-on for William being the common ancestor of all three.

That's not really news— it's long been suspected that all three lines tie back to William. What's more significant is that there aren't private mutations that are shared by two of the testees but not the other. For example, if the John of Garrard County and Richard Harve descendants had a private variant not shared with the Robert Slaven descendant, it would be strong evidence that they are more closely related— as in, father/son. Lacking such a shared mutation is not proof that John and Richard are not father/son, as Y-chromosome SNP mutations don't occur every generation, but it's consistent with them being in separate branches (not father/son).

R-FTB71305, the "William Slaven haplogroup," split off from haplogroup R-BY50792, which formed between the year 1050 and 1550. In turn, it branched off from R-FT74770 between the years 850 to 1350. Surnames associated with these older haplogroups are Campbell, McWilliams, Murray, and McCurrie (R-BY50792), and Eagen, McSorley, Campbell, McQuaid, Hughes, and Keogh (R-FT74770). While Campbell is usually thought of as Scottish— Clan Campbell was one of the most powerful Highland clans— nearly all the men in the R-BY50792 and R-FT74770 haplogroups identify Ireland or Northen Ireland as their ancestral origin.

Since only one descendant of John Slaven of Highland County has tested (me), FTDNA can't assign a "family" haplogroup like the one for the William Slaven family. I have 12 private variants— 12 mutations not found in other men's results in the database; until another John of Highland County descendant tests, there's no way of knowing which mutations occurred before John, which occurred after, and whether any began with John.

So the current haplogroup for descendants of John of Highland County is R-DF97, arising from a man who is estimated to have been born around 1,300 years ago, plus or minus 250 years. This haplogroup is currently (July 2022) shared with nearly 500 men in the FTDNA database, most of whom report an Irish origin.

Notably, the William Slaven and John of Highland County lines don't connect until you trace both lines back to haplogroup R-S658, which arose in a man who is estimated to have been born around 1,900 years ago, plus or minus 350 years. That corresponds to about 100 CE with a 95% probability he was born between 250 BCE and 450 CE— in other words, centuries before surnames were used in Ireland. So...

A wish list...

My first wish for additional Big-Y testing would be that the test wasn't so expensive. Thankfully upgrades to the Big-Y from an existing Y-25, 37, 67, or 111 test are cheaper than a whole new test, and FTDNA has sales on upgrades several times a year. The Slaven DNA project at FTDNA accepts donations to the General Fund, if anyone would like to chip in on the cost of someone's test.

Beyond that, it would be great to get additonal descendants of William Slaven/Esleven/etc. of North Carolina to test to see if SNP mutations will further define the family branches. Of prime interest would be:

Because of the cost, I don't feel I can make a blanket recommendation that every male Slaven/etc. take the Big-Y test or upgrade to it. I'd be glad to discuss the pros and cons via email. Thanks!

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