Wednesday, January 27, 2010

Genes That Fit Just Right: DNA Testing & Genealogy

This post was updated with new information on July 8, 2010

Since I have been dealing with genetics, I thought it might be helpful to discuss molecular genealogy as the next in this series.

A little over two years ago, I was at a luncheon meeting when the topic of DNA testing for genealogical purposes was introduced into the conversation. One lady at the table made the comment that she was thinking about having her DNA tested to discover all of her nationalities that she had in her ancestry. This was prior to the introduction of Autosomal and X Chromosomal DNA testing now offered by 23andMe and Family Tree DNA. Her discussion centered around the two tests that had been offered for a number of years and centered around the testing of Y Chromosomal (Y-DNA) and Mitochondrial DNA (mtDNA).

My friend made the error of thinking that these genealogical DNA tests were going to be the Rosetta Stone for all of her queries and questions. Sadly, this is common misconception of what DNA testing is going to report. Unless you are prepared for the types of results that you will receive from Y-DNA and mtDNA, you may be singing that old Peggy Lee standard, “Is That All There Is?” In many cases, you may be very disappointed as there is not much bang for the buck for some types of genetic genealogical tests.

With what you may consider dismal results with Y-DNA & mtDNA, you may be expecting something that these two tests will not deliver. There are several misconceptions concerning this type of DNA testing which is offered by most companies selling genetic genealogical tests. These include the following:

  • I will learn my complete ethnic profile.
  • I will find out exactly where all my ancestors originated.
  • I will know all of the health issues that I can expect to have during my lifetime.
  • I will be able to go to a database and find my complete ancestry with connections to all my unknown cousins.
  • Someone else having access to my DNA makes me vulnerable.

Some of the above are inaccurate or partially accurate due to specifics. We’ll address these thoughts individually.

I Will Learn My Complete Ethnic Profile

DNA testing is not cheap. Outside of the initial sticker shock for price, I believe that discovering the tests' limitations after purchase is the biggest shock for most people. First of all, Y-DNA and mtDNA genetic testing will identify us with a group of people that share common genetic markers. In some cases, this is fairly broad.

Genetic anthropologists are able to map certain wide populations based on genetic mutations that naturally occur over time. Sometimes these mutations are so significant to descending populations that they are classed as a specific group.

These groups are called haplotypes, clades, or haplogroups. Other mutations that are less significant over time may produce a sub-haplogroup or sub-clade that shares many of the same markers as the larger group, but can be identified by a specific mutation. These groups are identified by letter and in some cases, nicknames for the various haplogroups.

Let’s get something straight about these mutations. These are not the same kind of mutations that were often portrayed on shows like the “X Files,” but rather changes in the genetic coding over time. Not being a geneticist, I am not sure whether these mutations create any distinct characteristics or not. Perhaps they do, but that is beside the point. Genetic anthropologists can, however, estimate the approximate time the mutation occurred and get a sense of the geographic region that this haplogroup or sub-haplogroup covers.

Second, we have to understand that there are two DNA tests that most companies make available and these are based on unique genetic material that is passed down from parent to offspring. Neither one of these tests will completely explain our entire ancestry. At most, we will have two lineages that can be tracked – a matrilineal ancestry and a patrilineal ancestry.

Recent advances in testing of the 22 autosomal chromosomes and the X chromosome will answer some of these questions - but certainly not all. They can reveal some of the markers that conform with markers of certain ethnic groups; however, because of the DNA we inherit from our parents, all of the possible ethnicities we may have in our ancestry may not be present in our DNA. For example, our full siblings on average share about 50% of the same DNA as us. Ancestral markers found in one sibling, may be missing in others.

I will deal with Autosomal DNA and X Chromosomal testing in future posts for the following reasons: they may be somewhat restrictive in establishing genealogical relationships - because every ancestor may not be represented (this is especially true with X Chromosomal tests); they are not offered by the majority of companies; the tests can be expensive; and although I have been tested, I am waiting for further results by members of my family to provide an adequate assessment of these two tests. For the purpose of this post, I am limiting the discussion to mtDNA and Y-DNA types of DNA testing.

Mitochondrial DNA (mtDNA)

Both men and women can have an mtDNA test to trace their matrilineal lineage; however, if you are a woman, you can only trace your matrilineal line. With mtDNA, certain genetic markers are passed directly from mother to child; therefore, starting with yourself, you can track the DNA from you to your mother, to your mother’s mother, to your mother’s mother’s mother, and so forth. Ancestry.com tested two regions that included four markers determined my mtDNA haplogroup. Other companies are now offering a more comprehensive test of mitochondrial genetic material.

Mitochondrial DNA can be used to determine relationship; however, there is no way to determine if you are recently related or if that relationship extends back centuries. With only four nucleotide markers tested, not much can told other than the haplogroup of the individual who is tested and whether someone else is conclusively related via their matrilineal line.

The only way to confirm a relationship is to compare your results to paper based genealogical records. My earliest fully known mtDNA ancestress is Anna Barbara Faber (b. circa 1680; Knittlingen, Neckarkreis, Württemberg). I actually can go back one more generation to her mother. While I know her mother's first and middle names of Anna Catherina, the maiden name of 8th great-grandmother who was born circa 1643 is unfortunately unknown.

Y Chromosome DNA

While men and women both can be tested for mtDNA, only men can be tested for Y Chromosomal DNA, as only men carry the Y chromosome. This type of DNA is passed from father to son and (in most cases) will follow the surname line. The only time it will not follow the surname is in cases where a name has been changed by a male ancestor or if an illegitimate child takes his mother’s surname. In both situations, the Y-DNA follows the patrilineal lineage via the father and will be carried forward despite different surnames. Y-DNA is more exact than mtDNA as more markers can be tested.

Different services offer different tests that include 8, 12, 33, 37, 43, 46, and 67 markers. With more markers, there is both good news and bad news. The good news, the greater number of markers increases the accuracy in guessing the most recent common ancestor (MRCA) that you and another person share. The bad news is that an increased number of markers has a corresponding increased price tag.

Personally, I purchased the largest number of markers available through Ancestry.com and that was 46 markers. Since I waited for a publicized sale, I was able to get this large number of markers for a bargain price. I am now awaiting results from an upgrade to a 67 marker test through Family Tree DNA.

My advice is go with a middle level test of between 33 and 43 markers, as the price can be competitive and there are more chances that those with whom you compare tests will have a comparable number of markers. Eight or 12 markers will not nearly be enough to be accurate and 67, while more accurate, may be overkill if few others have this test.

If they do, you still will be able to compare enough markers to gauge the MRCA within a few generations – and this may be sufficient. Although it sounds somewhat hypocritical, I decided to upgrade as FTDNA had a special upgrade for Ancestry customers. In addition, the 67 marker test is the gold standard for DNA surname projects of which I plan to start for my surname of Owston and its variant Ouston.



Like the mtDNA, there are haplotypes, clades, or haplogroups for Y-DNA. These are also named by letter and may share the same letters as mtDNA haplogroups; however, mtDNA and Y-DNA haplogroups sharing the same designation are not the same groupings. Like mtDNA, geographical concentrations can determine the sources of these ancestors.

Since Y-DNA is more accurate than mtDNA and can indicate more recent relationships, there are ways females can gain this data. For women interested in having this information, a test must be run on the DNA of a male relative in their fathers’ lineage. This could include the following blood relatives:

  • Your father,
  • Your grandfather (i.e., father's father)
  • Your brothers,
  • Your half brothers that share the same father as you,
  • Your uncle – (i.e., father’s brother),
  • Your uncle (i.e., father’s half brother that both share the same father),
  • Your nephew (i.e., the son of your brother),
  • Your nephew (i.e., the son of your half brother that shares the same father as you).
  • Your male first cousin (i.e., the son of your father's brother).
  • Your male half cousin (i.e., the son of your father's half brother that shares the same father)

I WILL FIND OUT EXACTLY WHERE MY ALL MY ANCESTORS ORIGINATED

Finding exactly where all of your ancestors originated will not be possible with any type of DNA testing. You may be able to be somewhat successful in this endeavor with Autosomal and X Chromosomal testing; however, these tests find matches and if the person who shares your DNA would need to know more about your shared lineage than you do. Autosomal DNA can predict relationships usually no further than 11 generations and are more successful in connecting third, fourth, and fifth cousins who share common ancestors at the corresponding fifth, sixth, and seventh generations.

As far as Y-DNA and mtDNA are concerned, paper genealogy is of little use as the common ancestor for your haplogroup with be thousands of years in the past. With that said, by noticing population concentrations exist for your specific haplogroup, you may make reasonable inferences concerning family's origins. By comparing with others who share DNA matches, you may be able to determine more recent locations of your family roots.

In my case, my matrilineal line could be traced back to Würtemburg. My mtDNA haplogroup was originally identified by Ancestry.com as H, which has been nicknamed Clan Helena.  It is assumed that haplogroup H originated in the Pyrenees Mountains in the border region of France, Spain, and Andorra. My wife’s mtDNA was also among haplogroup H, but her markers were dissimilar to mine - so our genetic connection probably goes back several thousand years.  In addition, Clan Helena is the most pervasive mtDNA haplogroups of European origin* with between 45 to 53% of all Europeans sharing this mtDNA grouping. In both cases, I was hoping to find something exotic; however, this was not the case.

Since my initial mtDNA test, 23andMe's testing of single-nucleotide polymorphisms (SNPs or snips) is more accurate at determining a person's haplotype. Due to mutations, 23andMe recorded my haplotype as being more distinct than H and is now listed as H23. This haplogroup, which appears to be found among central Europeans and specifically Germans, fits my known ancestry.

My patrilineal lineage can be traced back to the East Riding of Yorkshire in England. This was an area that had once been under Danish rule, and due to Viking conquests in the area, Old Norse words were introduced into Old English and are prevalent in this part of Britain.

The spelling of my surname also seems to have been influenced by Old Norse with a change from Æston to Owston. So there was no surprise that my Y-DNA haplogroup was I1, which has its greatest concentration in Scandinavia. This fulfilled my expectations of my ultimate paternal heritage. Since my initial test, 23andMe's analysis of my Y-DNA SNPs has further designated my haplogroup as I1*. By the way, my earliest known Y-DNA ancestor was Peter Owston who died in 1567 in Sherburn, North Yorkshire.

In either case, the exact migration of these ancestries cannot be ultimately mapped. As more people are tested and more matches are found, a comparison of family histories (where known) may provide some additional clues to a point. As for now, I have two exact matches with mtDNA and no close matches with my Y-DNA.

I WILL KNOW ALL OF THE HEALTH ISSUES THAT I CAN EXPECT TO HAVE DURING MY LIFETIME

While autosomal genetic testing may be able to provide clues on the probability of certain diseases, mtDNA and Y Testing do not provide this information. At least one company bundles this testing with genealogical testing. 23andMe offers this service and it greatly affects the ultimate price you will have to pay for the combined tests.

I WILL BE ABLE TO GO TO A DATABASE AND FIND MY COMPLETE ANCESTRY WITH CONNECTIONS TO ALL MY UNKNOWN COUSINS

Several companies provide a service where genealogies are posted in reference to DNA. Other sites that compare DNA for specific surnames also exist at the present. Even with these options, DNA will never provide your complete ancestry; however, you may be able to reconstruct relationships at least in your paternal lineage. As one goes back in time, the availability of records proving relationship lessens. There will be a brick wall you will eventually hit unless your paternal line is a royal line that is well documented. Autosomal and X Chromosomal DNA is better for connecting to more recent cousins than Y-DNA or mtDNA.

SOMEONE ELSE HAVING ACCESS TO MY DNA MAKES ME VULNERABLE

With the constant threat that our identity might be compromised, there is the paranoia that someone, big brother perhaps, will have direct access my DNA information. Not only do people fear a violation of their right to privacy, there is the sense that our DNA may be used to our disadvantage.

DNA testing is voluntary – if you decide to be tested, you may opt out having your information posted. The DNA information collected for genealogy, however, is an infinitesimal portion of your entire DNA profile. With mtDNA and Y-DNA, only ancestral markers are tested.

These markers are not unique to you but rather to you and other relatives - perhaps to many other relatives. There is that distinct possibility that all male relatives that share your paternal lineage with a relationship back numerous generations may share the same Y-DNA markers as you do. With mtDNA, there may be people sharing a common ancestor 20 generations or more in the past that also have the same mtDNA results as you.

Close relatives through the same descent will share the same markers. Those living with whom I am aware that have the exact mtDNA as me are the following: my mother; one first cousin; three first cousins, once removed; and three first cousins, twice removed. I am reasonably sure that the following living individuals share the same Y-DNA as me: my two brothers; my five nephews; one second cousin; and one second cousin, once removed. There may be many others as well.

One needs to realize that Y-DNA and mtDNA testing is not the same DNA tests that are used in crime scene investigation as seen on TV. That type of DNA testing chronicles your complete chromosomal makeup and will be unique to you. This is beyond the scope of the standard genealogically based DNA tests, so unique DNA information is neither tested nor is it publicized in any manner. Unfortunately, Autosomal DNA is the same test used for identification purposes and it is unique to you as an individual. X-Chromosomal tests can be used to show relationship among siblings.

OUR EXPERIENCES WITH Y-DNA AND mtDNA

We bought the DNA tests in late 2008 when a special offered was available through Ancestry.com. The results were returned within three weeks. I had also sent samples of DNA to be tested by Sorenson Molecular Genealogy Foundation. This additional test was to be free and it was to include genealogical data that could be compared with other subscribers. The results took 9 months and were not free; however, their testing partner significantly dropped the price when the first offer to purchase the unlock of the information was ignored. The mtDNA unlock was reduced to under $20.00 and their 8 marker test for Y-DNA was twice as much. I purchased the mtDNA unlock and my genealogical data was posted along with my DNA info. Since then 23andMe's SNP testing has further defined my haplogroups for both Y-DNA and mtDNA.

WHAT I HOPE TO DISCOVER WITH MY OWN SEARCH

With the research in regards to my surname, there are some questions that I would like to have answered. First of all, there are two lines from my specific family that, although I have linked to the most common recent ancestor (MCRA), I am not 100% sure that a genetic relationship exists. I would like to have representatives of these two lines tested to positively verify or deny a relationship.

One of these two lines has an individual that may have been an adopted stepson rather than, as with the common family opinion, being an illegitimate son that was later legitimized. This identity question is raised because the subject is listed with a different last name in the 1870 census. Since he was born after the taking of 1860 census, there is no prior listing of the name and civil registration of births was not mandatory until the 1880s. Therefore, conclusive documented evidence of his paternity does not exist.

The second relationship is inferred due to photographic evidence of an old tombstone that carries the name of my ancestor’s brother. Since a member of the questionable line is sitting on the tombstone, it has been assumed that this person (who shares my surname) and his siblings were grandchildren of the man whose name is on the tombstone.

I am perfectly happy in making this leap of faith as the indication of relationship is supported by the photo. Since no direct evidence exists to prove or disprove the connection, a DNA test would confirm or deny the accuracy of the relationship.

There is one more area I would like checked. Two other groups of individuals share the same surname as our specific family. These other groups come from the same region of England as my family; however, there is no conclusive evidence that we are related. Y-DNA testing would be able to confirm or deny if any of these three groups are connected. If there is a connection, these connections are not verified by parish registers as the MCRA would have occurred before the keeping of such registers were mandated in the 16th century.

There is also the possibility of tracing my other family lines by having other individuals tested with the particular Y-DNA or mtDNA for these lineages. The problem I have with this is finding descendants that qualify for the test and who would be willing to be tested.

For example, my great-grandfather, Thomas Wesley Day only had daughters. He was the only surviving son of his father’s family, so I would have to find a male descendant of my third great grandfather. Finding such a fourth cousin may prove to be difficult with a common surname such as Day.

DNA testing is not for everyone and it may not be something that helps you in your genealogical quest. Even with the aforementioned shortcomings, some have been successful in finding ancestors and making a connections to their own lineage.  This alone would be an invaluable tool if all avenues of research to this point have led to dead ends.

DNA CASE STUDY

In the following video, genealogist Megan Smolenyak Smolenyak discusses how she traced four lines that share the same surname in the Roots Web Television's DNA Story episode: "Did She Marry Her Cousin?"


*Besides, haplogroup H (Clan Helena), other European mtDNA haplogroups include: J (Clan Jasmine), K (Clan Katrine), T (Clan Tara), U ( Clan Ursala), X (Clan Xenia), and V (Clan Velda). The European mtDNA clans were named by Bryan Sykes in his book, The Seven Daughters of Eve.

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