An Analysis of Progress To Date in the Crago Surname DNA Testing Project -- June, 2012
In order to analyze progress to date we must first be clear about what we hope to learn from Y-DNA testing of living Crago males. In this brief write-up, I'll attempt to list the project objectives I see at this point in time, -- and a summary of what we have learned so far. (ALSO BE SURE TO READ the Project Background and Project Goals sections.)
First, can we prove that most of the Crago's in North America descend from just one Crago Male?
ANSWER: Yes, it seems that we can. We estimate, based on DNA studies to date and the number of different family lines tested, combined with an extensive database of more than 3500 different Crago's and Craigo's and their various family links, that at least 65% of the Crago's and Craigo's of America share a single paternal ancestor. Most other differing Crago and Craigo DNA profiles found to date seem to be the result of relatively recent non-paternal events (NPE's). It seems quite possible, but as yet unproven, that there may be a single Crago paternal ancestor for all Crago's and Craigo's in the world who carry the surname (e.g., I am referring here to at least a common family connection, if not always a genetic one). Some researchers have suggested the possibility of two different Crago lines, if one goes back into the 15th or 16th century. But, we have found no convincing DNA evidence of that possibility to date. Quite the opposite.
The apparent incidence rate for Non-Paternal Events (NPE's) among the Crago's and Craigo's in America would seem to be rather consistent with the 1.3% NPE incidence rate per generation which other researchers have calculated and reported in their surname studies. If this rate holds relatively constant in other surname groups, one would expect only about 80% of the male descendants of a single paternal surname ancestor to carry the DNA profile of that ancestor after 17 generations of NPE's, (or, in other words, since roughly 1500 AD). We currently have about 15% of the Crago's and Craigo's in America who do not have an identified DNA profile, due to an absence of volunteers from those family lines. After these other Crago and Craigo lines have been tested, our current 65% conformance figure among the entire population could approach the hypothicized 80% range that one might expect if there were just one ancestral source for the surname.
-- We can now say we have a "branch marker" pattern for the descendants of Thomas Crago of Wood Co., OH. A value of 13 on marker 617 seems to be the "signature" for descendants of Thomas Crago of Wood Co, and we have found no other Crago's with this value who also have the "Thomas Crago DNA Profile."
We also have an apparent "branch marker" for descendants of Thomas Crago of Greene Co., PA -- the value of 9 on marker 450. We can say with some confidence that the Wood Co. Thomas Crago (whose descendants all seem to have a 9 on Marker 4450) doesn't appear to be a descendant of the Ross Co. Thomas Crago, whose descendants all appear to have a vaue of 8 on Marker 450.
This result makes it much more likely that the Wood Co. Thomas Crago is a descendant of the elusive James Crago of Washington Co, PA. We have at least one reliable account which states that James was a son of the Greene Co, PA Thomas Crago who was killed by Indians about 1771, and this Thomas may have had a value of 9 on Marker 450. James seems to have moved to the Ohio frontier (perhaps Stark Co., Ohio), some time between 1790 and 1800, and to have died there before 1820.
The bottom line is that we have now proven via DNA that it is more likely that James was the ancestor of the Wood Co., OH Thomas Crago, than that Thomas Crago Jr., of Ross Co., OH was the ancestor.
Second, do the Craigo, Crego, Crage, Craig and other variations of the Crago surname found in North America share a single male Recent Common Ancestor, or RCA (i.e., born after 1500 AD)? In other words, is our "Thomas Crago DNA Pattern" also the male ancestor of these variant surnamed individuals?
ANSWER: While we know that some Crago, Craigo and Craig volunteers share a recent common ancestor, we have also learned that not all Crago's, Craigo's and Craig's share a recent common ancestor. This is hardly surprising, since Non-paternal Events (NPE) occur in most families.
We have learned that our first Crego volunteer, with documented roots back to Cornwall, England, does not share the Thomas Crago or Nathan Crago DNA patterns. But, one Crego is certainly not conclusive. We'll look for a confirmation test of another Crego in the future.
And, we do not yet have test results for a Craige, Craigie or Crage male volunteer -- We hope that one or more will be willing to volunteer for testing in the future.
Discussions with the Craig surname study group administrator have established that none of the numerous Craig's tested in that project to date match any of our 18 Crago/Craigo volunteers. But, in our Crago group, we do have one Craig volunteer with documented ancestry who matches our Thomas Crago DNA Profile. This is significant because we know that some Craigo's, for a variety of reasons, have changed their surname to Craig in the past. We have identified by paper research at least 42 Craig-surnamed individuals in this category, and we know there are more.
Third, can we demonstrate that the early Crago immigrant(s) to North America share a recent common ancestor with the Crago's of Cornwall, England, Australia, Canada, South Africa and New Zealand? Or, stated another way, can we prove the origin of most Crago's in the World was in Cornwall, England?
ANSWER: The answer to this question would appear to be "Yes". We have found good evidence that most Crago's and Craigo's in North America can point to a common ancestor in Cornwall, England in the early 1600's. We do not yet know his name, but we will continue working on that. We still hope to attract volunteers from Australia and New Zealand.
We recently completed a DNA test done on one of the South Dakota Crago's with documented roots back to Cornwall, England. This is a relatively recent immigrant group to America, and provided a clear link to Cornwall, England that we have been looking for.
A FINAL NOTE: Some volunteers might wish to know how many markers they need to have tested in order to provide enough information for this Crago DNA study. In most cases, it appears that a 37 marker test should be the most appropriate test. So far, none of the 134,000 plus persons tested by FTDNA have had a 37-marker haplotype which comes closer than a genetic distance of four (4) to our ancestral Thomas Crago haplotype -- unless their name was Crago or Craigo. Our ancestral Thomas Crago haplotype appears to be rather unique.
We know less about the recently determined Nathan Crago DNA tree at this time, but it is clearly different in substantial ways from the Thomas Crago DNA tree. A 37-marker test, however, would clearly distinquish between the two major family lines.
Please feel free to share this information with others, and we'd be happy to answer questions for any reader, if we can. Of course, we welcome new Crago/Craigo/Craig/Crego volunteers as we continue to build this genetic Crago family tree.
Footnote: A recent common ancestor (RCA) in this testing context is considered to be an ancestor within a conventionally researchable timeframe. In other words, this means an ancestor born since about 1500, when surnames came into common use.