Basic Y-DNA tutorial. What is the deal with Y-DNA and why are we interested in it in connection with genealogy? The answer is that what differentiates a male from a female, at the DNA level, is that males have a Y- and an X-chromosome, whereas females have two X-chromosomes. Since only males have Y-chromosomes, this means a man's Y-chromosome is identical to his father's Y-chromosome, and the same as his paternal grandfather's Y-chromosome, and so on. In other words, the Y-chromosome is passed from father to son. Since surnames are also passed from father to son, it follows that all people with the same surname should have identical Y-chromosomes.
However, we all know that surnames change slightly from time to time. For example, in the late 1700s and early 1800s, my surname ancestors spelled their names as Hathcock. In the middle 1800s, when Alfred Hathcock settled in central Texas with his four sons, John, Asa and Columbus, the name acquired an "e" and became "Heathcock." In other parts of the country, we find the same family name spelled as Hethcock, Hathcock, and Haithcock. In addition, some of our Hathcock relatives chose to deliberately change the name by replacing "cock" with "coat" and now we have cousins whose surname is Hathcoat (like Paul, the founder and co-administrator of our surname project).
In a similar way, the Y-chromosome DNA sequence can undergo small changes from time to time. The Y-chromosome DNA markers that are evaluated are called "short tandem repeats" (STRs). At each of the 67 markers that are tested, the STR has a value like 9 or 13 or 26. This is the number of times a given DNA letter sequence is repeated. However, occasionally when the DNA is copied, the machinery makes a slight error and instead of making a copy with 26 repeats, it might "miscount" and make a copy with 25 or 27 repeats. Biologists sometimes refer to this as a "stutter". The probability of a miscopy is low--only about 0.2%. However, since we evaluate 67 DNA loci, the chances of a miscopy in one of them is 0.002 x 67 = 0.134 or 13.4%. That is, in each conception event, the chances are about 1 in 7 that the son will get a slightly altered copy of Y-chromosome DNA from his father. This then becomes the son's version and he will pass it on, with the error, to his sons (at least to 87% of his sons, since there is a one in seven chance that there will be another copy error in the conception of each of his sons).
How to Join the Project. The Y-chromosome DNA test is simple to carry out and is relatively inexpensive. Contrary to what many people think, it is not necessary to provide a blood sample. Instead, the actual test consists of swabbing in your cheek with a small cotton swab, which is sent to the testing laboratory. In a few weeks you get a report of the profile. Visit this link to join our surname group and order a test kit.
So far our group has 22 members and we have also received reports from a number of others whose tests have been carried out by other testing laboratories. At the moment, it is possible to get a full report of 67 different markers. Alternatively, one can purchase smaller marker sets--12 or 37. For the best chance of learning where you fit in to the greater family, it is strongly recommended that you start with the Y-DNA37 test.
Privacy. The DNA samples collected will be analyzed purely for anthropological and genealogical data; no medically-relevant data will be collected or analyzed, nor will the the DNA be shared. The tests do not tell us anything about your health or about health problems you or your family may have. In addition to that, in 2008 the Congress approved legislation that was signed by the President, preventing insurance companies to use DNA information to deny insurance coverage (the GINA Act).
Results. Click here to see the results to date. This table shows that three men, Walter Liston Heathcock, Danny Colon Jacobs, and Marcus Edward Norton, all have the same profile at the full 67 markers. A number of others have the same profile at all but one or two of the markers. At the moment, we are working on the assumption that Walter, Danny and Marcus have a profile that is unchanged relative to that of our earliest common male ancestor. My own profile is identical to the "family modal" in all of the marker sites except at marker number 32, where my DNA has 17 repeats, compared to 16 for the family modal.
It is actually the small deviations from the family consensus that are most useful for genealogy. For example, James David Hathcock Jr. and Earl Williams both differ from the family modal at markers number 10 and 12 (these two markers are coupled, so this does not correspond to two mutations, but only to one). This tells us that James David and Earl share a common male-line ancestor who lived more recently than the earliest common ancestor for the surname group. We don't yet know who this was, but some tests that are currently underway may shed some additional light on this puzzle.
Study Chart. A chart that shows some of our surname group with their established or suspected lineage is here. There are some hypothetical linkages in this chart. One is very hypothetical indeed. Three of our surname group, Tucker Lynwood Hathcock, George Ray Hathcock, and Michael Carl Johnson all have a one-step mutation at marker #34 (CDYa). In addition, Lynwood has another one-step mutation at marker #30 (DYS456), whereas George Ray has an additional one-step mutation at marker #35 (CDYb). This suggests that these three men had a common ancestor who lived more recently than the global common ancestor for the entire group. Lynwood's pedigree back to Peyton Hathcock is rather solid. However, we know that Peyton's father, John Hathcock Sr. (of Madison Co AL) did not have the mutation at marker #34 because others of his descent do not (including me, Clayton Heathcock Jr.) Therefore, the hypothesis is that Peyton acquired the marker #34 mutation from his father, whereas his brother Alfred Hathcock did not. This means that Peyton is also the male ancestor of Michael Carl Johnson and George Ray Hathcock. Since Peyton was clearly a scoundrel (see a brief synopsis of his life), the working hypothesis is that he was the father of both Black Jack Johnson and Henry Haithcock Jr. This may seem like an outrageous suggestion, it seems the simplest working theory we have to account for the fact that the marker #34 mutation is shared by Lynwood, Michael and Ray.
Surname Variations. You will notice that the study group includes a number of men with names other than Heathcock or an obvious variant. In a few cases, we have a very good idea how these men came to have Heathcock Y-DNA but another surname. For example, the Nortons trace their ancestry back to James Norton, who married Martha Hathcock in the early 1700s. Martha was the daughter of Edward Hathcock, from whom most of the Heathcocks trace their descent. We believe that Martha and James adopted the son of one of her brothers, who had Hathcock DNA, but raised him with the Norton surname. Another case we understand to some extent is Alfred Wayne Smith, of Roanoke, Texas. Alf was born out of wedlock and his mother never told him the name of his father. Alf knew that his original birth certificate gave his name as "Alfred Junior Parish" (his mother was Juanita Parish) and he had always suspected that his father might have been named Alfred. When his DNA results showed that his profile is virtually identical with the family modal, we did some internet sleuthing and discovered that when Alf was born, in Dunklin Co MO, there was a nearby Heathcock family who had five sons, including one named Alfred Wheeler Heathcock. We are pretty sure that this was Alf Smith's father. A similar case is Earl Williams, who traces his lineage back to Franklin Randolph Dixon, who was born out of wedlock to Cleopatra Dixon in 1858. His descendants were all aware of this fact but none ever knew the identity of his father. Once again, a bit of internet sleuthing revealed that there was a Heathcock family in the small village where Cleopatra Dixon lived in 1858 and that one of the sons in that family was Franklin Hathcock. There is a good chance that Franklin Hathcock was the father of Cleopatra Dixon's son, Franklin Dixon Randolph. A complete summary of the living men who have been shown to have the "Hathcock family haplotype", with their known of suspected descent, follows:
Hathcock or Variant (descent from Edward or Joseph Hathcock, early 1700s):
Nortons (descend from Isham Norton, 1752-1833, a biological Hathcock):
Jacobs (connection with Hathcock haplotype unknown):
Other surnames:
Origin of the Heathcock Surname. It has been widely accepted, mainly due to the exhaustive work in the 1960s-1980s by family genealogist Douglas Wilburn Hathcock, that the surname came to America in the person of 21-year old Thomas Heathcock, who was imported by William Stone as an indentured servant. We know that Thomas came from Gravesend, England on a ship named Paule and that he arrived in Virginia in the summer of 1635. We do not know more about Thomas Heathcock (spelled Hatcock in the original document that records his entry). In fact, the next people by the name for which there are extensive records are Edward Hathcock and Joseph Hathcock, both born about 1700. Edward and Joseph lived near each other, one on each side of the state line that separated Virginia from North Carolina. They were likely grandsons or great grandsons of the immigrant Thomas Heathcock. All of the modern American Heathcocks (or variant spellings) trace their lineage back to either Edward of Joseph Hathcock.
Modern English Heathcock DNA Profile. However, although Edward and Joseph probably got their Hathcock surname in the normal patrilineal way from the immigrant Thomas Heathcock, it is beginning to appear that they did not get their Y-chromosomes from him. Three modern English Heathcocks have become members of our surname group project and their Y-DNA profile is quite different from that of the American Heathcocks. These three men live in different parts of England, do not know each other, and do not have a known, close family connection. They have the same Y-DNA profile and presumably respresent the English Heathcock family modal. Our project is interested in adding other modern English Heathcocks to the project.
Ancestral Haplotype (Family Modal). If Thomas Heathcock brought the surname to America, but not the DNA, then where did it come from? In using DNA for the study of evolution, scientists use the term "haplotype" to describe a unique DNA sequence. Thus, what I called the "family modal" (the sequence of markers shared by Walter Liston Heathcock, Danny Colon Jacobs, and Marcus Norton) could also be called "the ancestral haplotype." Similarly, each of the men in our surname group who differ from this ancestral haplotype can be said to have a slightly different haplotype.
Our Haplogroup. Scientists also use the term "haplogroup" which means a group of similar haplotypes that define a genetic population. In other words, a population that is descended from a common ancestor, as evidenced by a specific "single nucleotide polymorphism) (SNP). There are many haplogroups and each has its own scientific notation. Many of the Hathcoat/Heathcock surname group members have been tested for SNP and our haplogroup is E1b1a, sometimes called M2. The following definition of this haplogroup is taken from Wikipedia:
Haplogroup E1b1a is the main haplogroup in sub-Saharan Africa, where it reaches frequencies of over 80% in West Africa. It has been hypothesized that E1b1a originated in Northern Africa and then spread to sub-Saharan Africa with the Bantu expansion. E1b1a is the single most common Y-chromosome haplogroup among people of Sub-Saharan African descent both inside and outside of Africa. It is observed at frequencies of 58%-60% in African Americans.
This suggests that, in some way that will probably never be known, an African man contributed the Y-DNA that those of us in our surname group all share and the son of this paternal event must have been raised with the Heathcock surname. I believe that this must have occurred very early, probably in the middle 1600s, as there still are no American Heathcocks who do not have the general family haplotype. Possibly it was even the immigrant Thomas Heathcock himself who adopted an orphan son of an African man and raised him as his own son.
Clayton Heathcock
Wednesday, December 30, 2009