The Rockwell Y-DNA Project
The Rockwell DNA project began in 2002 under the aegis of the Rockwell Family Foundation. A major goal was to learn if there is a relationship between the three major Rockwell family groups in Connecticut, as well as the mid-Atlantic line descended from Robert Rockwell/Rockhold. These four families are the source of most of the individual families in North America today, but no historical documentation definitively connected them. The early tests showed a close relationship between the William, John, and Josiah lines in Connecticut, while the Rockhold DNA signature proved quite distinct. This tool has the potential to point a Rockwell descendant with an unknown early lineage toward the right line.
How it works
The Y-chromosome contains lots of "junk DNA" that doesn't have any manifestation in our physical traits or health. But this "junk" is actually quite useful, since it contains patterns of nucleic acid base pairs that are passed from fathers to sons virtually unchanged. This allows us to distinguish between different lines of men with the same surname.
Researchers have noted that in numerous locations on the Y chromosome, a string of nucleic-acid base pairs may repeat itself several times. This string is called a “short tandem repeat,” or STR. The exact number of repeats may differ between individuals, usually over a specific range, for example 9 to 14. Each possible count is called an “allele.” If the allele at a given position (locus) tends to stay the same from generation to generation, the STR is considered a useful “marker” for testing relationships between individuals, for it will get passed down from fathers to sons over the generations, and cousins on different branches of a family will show the same allele. While two men may have the same alleles on some of these markers, a whole ensemble of matches on different markers points to a close relationship. Usually, a father and son will have the exact same alleles in each marker.
I say “usually” because now and then, during the process of copying and recombination at the time of conception, an imperfect copy of an STR is made and the marker picks up an extra repeat or two—or loses one or more. Then the son will differ from the father at that one locus, though the rest are the same. Such “mutations” happen only occasionally. The rate of mutation on different markers may vary—it’s still early in the study of such things—though an average of one mutation every ten generations has been suggested. But these mutations occur at random, so in a given paternal line, the ensemble of alleles (called a “haplotype”) may remain the same for many more generations than ten, or a mutation may occur on two different markers within a few generations. But due to the relative stability of the haplotype, genealogists are able to learn whether two men of the same surname are paternally descended from a relatively recent common ancestor.
Rockwell results and future plans
The early test results demonstrated that the three Connecticut lines were closely related. They don't tell the exact relationship, however. Only further documentation can give us that. But we can speculate that John and Josiah were related to William, whose origins are traced to the village of Fitzhead in Somerset, England.
The number of markers used in the early tests ranged from 12 to over 30. Now many more markers can be tested, and some of these may show certain "alleles" that are passed down in distinct lines. By obtaining enough samples, two men's haplotypes that look identical on 12 markers may become better defined, so that one might zero in on a particular branch of the family for one's origins. At least that's the hope.
To participate
Any man who carries the Rockwell surname may participate. The test is administered through FamilyTree DNA (FTDNA), the only company that currently offers the Y-DNA test. The Rockwell Family Association intends to sponsor participants through subsidizing the cost of the test. Contact us to express interest in participating.
