First, let me remind visitors and new members that our Y-DNA is inherited from a single male progenitor. Because SNPs rarely mutate, members of our I-L22 clade share a haplogroup descended from that one anonymous progenitor. Unlike SNPs, STRs mutate every few generations so recent generations are expected to have similar but not necessarily identical haplotypes. Because project members share the same clade, information that is applicable to one member will be applicable to the other members as well. In other words, any member may be a surrogate for other members of the group. Therefore, the following comments and analysis are applicable to all our members of the I-L22 clade.
Generally, we can correctly assume that STR markers identify lineages within genealogical times and SNP markers identify lineages within pre-genealogical (ancient) times. This is possible because STRs mutate more rapidly than SNP. Genealogical times correspond to written and recorded surname records.
In addition, we can use STR and SNP mutation data to develop other useful information. Geneticists have determined average mutation rates of both STR and SNP markers. The number and rate of mutations are used to calculate an estimate of the time period during which an ancestor was likely to have lived. When the number and rate of mutation for two haplotypes is known, it is possible to estimate the Time to the Most Recent Common Ancestor (TMRCA). Using SNP haplogroups, a similar estimate is possible for ancient ancestral populations but the information points to ancient changes and is of little use for genealogical purposes.
An early goal of the STURDEVANT surname project was to use DNA to determine whether the various STURDEVANT spellings are related (i.e., they descended from the same progenitor). Volunteers representing different spellings joined the STURDEVANT DNA effort and took Y-DNA STR tests to identify their haplotype. Similarities in haplotypes immediately revealed at least three or four groupings. Each group had one or more similar haplotypes which indicated that members of each group descended from different male progenitors. We now identify these groups with the I-L22*, R-M269 and R-M512 haplogroups and we know that each has a different progenitor. We also know that, over time, STURDEVANT spelling variations are of little value in identifying lineages.
The genealogical record shows that our I-L22* haplogroup descended from William Sturdevant of Norwalk who immigrated to Connecticut Colony before 1674. He is the known patriarch of the I-L22* haplogroup. At this time we do not yet know the name or location of William’s paternal ancestor, the earlier progenitor of our haplogroup. It is our hope that we may identify the progenitor through DNA analysis. To do that, we must continue to define and refine our haplogroup so that we know which branch, which limb, which twig, and, ultimately, which leaf, we descend from. By doing this, we are able to exclude persons that do not share the same SNP and STR characteristics. When that information is known, we can seek Y-DNA data of other persons to identify a common progenitor. It is important to understand that a male progenitor may not have a STURDEVANT surname.
Some additional useful information is provided by geneticists who have been able to determine the migration patterns and paths of our ancient ancestors who migrated from the African continent to Europe and on to other parts of the world over a period of thousands of years. As migration occurred, Y-DNA markers (SNP and STR) mutated and those mutations can be traced. The first I-L22 was born relatively recently, about 4000 years ago. The greatest concentration of I-L22 is in northern Europe and Scandinavia so that is a logical place to begin searching for William’s progenitor. Here is a great explanation of the I-L22 migration from Africa to Europe and Scandinavia.
Considering population migration, our search for William’s progenitor began with an effort to identify a haplogroup unique to William’s descendants. STURDEANT project members first tested at the 37 STR level and then the 67 STR level. Geneticists were able to examine the haplotype and infer that the haplogroup is I-M253 (think major off-shoot of the I branch). There are numerous subclades of I-M253 and it is one of the major populations in Europe. Additional testing to 111 STR markers provided further refinement and disclosed the William of Norwalk group to be I-L22, a subclade of I-M253. Still a major European population, even the 111 level was not sufficient to identify a “Sturdevant subclade.” We can now be certain that all of the members of this group are I-L22 even though their testing level only inferred I-M253. The results tables disclose some interesting similarities and differences in our haplotypes.
Haplogroup Identification and Refinement
In the meantime, a dedicated researcher and hobbyist, Professor Kenneth Nordtvedt, identified an I-L22 subclade with properties very close to our marker values. He has given it the temporary identifier “I-L22-241510.” There can be little doubt that we are members of “241510” even though it is not yet formally recognized or placed on the phylotree. Being a member of I-L22-241510 is much like knowing your branch of humankind’s family tree, but still not knowing exactly where you are on that branch. An added benefit is that Professor Nordtvedt also identified more than a dozen persons with other surnames that fall within I-L22-241510. You may view some of the haplotypes at the yDNA Haplogroup I: Subclade I1 Project.
More refined testing is now needed. The 111 STR level of testing is the most definitive commonly available to genealogists but, unfortunately, it is seldom sufficient to identify new subclades and identify smaller twigs and leaves. SNP testing may refine the haplogroup by identifying a subclade that is farther out on the I-L22 branch.
In the I-L22 clade, there are currently five major limbs or subclades that extend from that branch whose terminal SNPs are L300, Z74, L205 and P109. Z74 has the most identified subclades, so, reasoning the Z74 subclade to be the most likely, I took that Z74 SNP test. However, Z74 came back negative (Z74-) so the only thing learned was that William’s haplogroup is not I-Z74. The Z74 SNP test was not a particularly productive experience. Since there are thousands (and growing) of identified SNP, there wasn’t much logic in trying to determine a subclade by testing one SNP at a time…enter the BigY.
A few companies offer DNA tests that identify thousands of markers, both STR and SNP. FTDNA offers the BigY which tests several thousand SNP and STR markers and includes markers of all 23 chromosomes. It is “cutting edge” test that provides a look at the entire genome. The BigY tests SNPs that are identified well into the genealogical time period so it offers an overlap with STR testing. The down side is that it is expensive and designed for scientific purposes, but, perhaps, we can bend it to our genealogical purpose.
So, with this knowledge (and drink in hand), I decided to opt for the BigY (what the heck, you only go around once). I ordered the BigY from FTDNA with the assumption that it would definitively identify a branch of the human phylotree that we Sturdevants could say belonged to our patriarch, William of Norwalk. A BigY test was undertaken in Dec 2014 with the results expected in 2-3 months and another 2-3 month period required for YFull.com to analyze and report.
Status as of May 2015
After receiving the BigY analysis and report, I was surprised to find that it provides little more currently useful information than was already known. Results are extensive (see below), but, unfortunately, not immediately useful. Like the Z74 test, the BigY confirms our subclade is I-L22 but the subclade is now I-L22*. The addition of the asterisk (“*”) means the subclade remains unidentified and does not fit any known subclade currently located on the phylotree. The BigY also confirms that we are L300-, Z74-, L205- and P109- (“-” indicates a negative test result). Bottom line: the Sturdevant subclade that we are looking for is still not formally named or identified with a terminal SNP. So, here we are, still stuck out on an a limb that we will continue to call I-L22-241510 or 241510 for short. Actually, there is a plus side, because the BigY has effectively eliminated the known I-L22 subclades.
At this time, we must wait for additional information to become available and for one or more additional persons to undergo the BigY or similar test. At some time in the future, another person will be identified as 241510 and comparison of the two SNP reports will provide a common terminal SNP that will identify our subclade and eventually lead to our 241510 progenitor, William’s Ancestor. That is almost guaranteed; but I can’t say when that will happen. There is hope: of the 68 persons currently in the I-L22 group, one other person is also identified as I-L22*. Unfortunately, he is not 241510, so, like us, he, too, is waiting for a terminal (but different) SNP.
BigY Report and Analysis
BigY test results consist of thousands of raw data points but no detailed descriptions or analysis. Because of this, I am providing the full results report on a separate page with appropriate links so DNA project members will continue to have unrestricted access to the data. See H1011 Big-Y Report.