ySTR or Autosomal Testing???
After the last emailed "newsletter" I received some questions and comments regarding what ySTR or Short Tandem Repeats of the Y chromosome is, and the difference between it and autosomal testing, and which test is beneficial to my research. Well to answer that question let's take a look at what each test is, who can take it and what will they tell us.
Y Chromosomal or Y-DNA Testing
A Y chromosome DNA test or more commonly known as Y-DNA test, is primarily a genealogical test that is used to determine a direct male (more specifically your father's) patrilineal or direct male line of ancestry. Certain identified ySTR markers that are tested by the DNA testing company are given a particular numerical value. Those values are compared to the values of another tester cousin to see if any mutations occurred over generations of time, causing a difference in value in any of those markers between the two testers' results. It cannot be used to test your mother's father's line etc. It is only used to test a direct male lineage which means if you are not a male you will need to test a brother, father, paternal uncle, paternal male cousin etc of the line you are researching.
What will it tell me? You can visit this page for more technical background but in short, this test is beneficial in determining how closely one tester is related to another cousin tester. For example, hypothetically let's say Bob "Sproule" tested 67 STR markers and Jim "Sproull" tested 111 markers at FTDNA because they belong to the Sproul Project Group and they know they can compare their results on the Group Project Chart. Both Bob and Jim find out that they match enough markers at the 67 marker level that their most recent common ancestor (MRCA) was approximately eight generations back.
For those of us trying to find close cousins to collaborate with this is an incredibly useful revelation, HOWEVER. There's always a however, isn't there? Some of us may have enough of a paper trail in our genealogy that we might be able to find out who that eighth generation ancestor was and could possibly be our link. The problem is, Bob tested 67 markers. To see if the eight generation MRCA estimate holds, Bob will need to test out to 111 markers and see if his number of matched markers to Jim remains the same. Bob may find out that there are other mutational differences in further markers that could put that MRCA back twelve, sixteen or even more generations back.
How the mutations in the STR markers work is like this. All variants of Sproul it would seem to this point are all descendants of one man, Walter Spreull of Dumbartonshire, Scotland, Cir. 1285. Walter passed on his ySTR markers on to his male issue nearly exactly the same markers as his. His issue then passes on those markers to their male issue an so on, and so on up to today. What happens is the STR markers tend to mutate over a period of generations, some markers are very stable and hardly ever mutate and some are not so stable and can mutate more frequently.
The more markers the male tests is a greater level of confidence revealing whether you share the same STR values, mutations and all. The more you share the same values the closer you are as a cousin and share the same branch of Sprouls. This is the primary focus of the Sproul DNA group. We want to determine who we share the most STR markers with the same exact value. The more you share the closer you are related.
The ySTR test is basically a qualifier test to see who you are closely related to. The next step requires testing for SNPs (pronounced "snips") to establish individual branches of Sprouls that can give us a timeline as to when that branch occurred. This is important because this can link us to a specific branch in Scotland, Ireland etc to help narrow down our focus of research. I will cover SNP testing in a near future post.
There are basically only two companies that are currently testing ySTR markers, FamilyTreeDNA being one of them, which includes HeritageDNA as they have their tests done at the FTDNA lab in Houston, Texas. If you believe you have tested with the now defunct ySTR DNA testing companies such as RelativeGenetics, Genetree or Ancestry (all bought out by Ancestry) prior to 2014 you may likely have ySTR results from one those companies.
If you would like more information about this test please comment below so we can create a dialog for others to follow along for information and clarity.
Autosomal Testing
According to ISOGG, the technical definition of autosomal testing is "Autosomal DNA is a term used in genetic genealogy to describe DNA which is inherited from the autosomal chromosomes. An autosome is any of the numbered chromosomes, as opposed to the sex chromosomes. Humans have 22 pairs of autosomes and one pair of sex chromosomes (the X chromosome and the Y chromosome).
Many of you I'm sure have seen the Ancestry commercial where the gentleman is dancing in his lederhosen because he was always told his ancestry was German until his Ancestry test told him his ancestry is really Scottish. Pop-quiz...what did he trade his lederhosen in for???
This is autosomal testing. This test is useful for determining your ancestral origins and what percentage breakdown of the regions or countries around the world your DNA comes from. Unfortunately it won't help us in determining who our closest cousins are for collaborative research. It is useful in determining cousins from all sides of your family that have also autosomal tested, up to a point. Through a process called "recombination" it becomes unreliable after 5-6 generations. For more information on this type of testing please visit this informative, less technical background on autosomal testing.
Some of the more popular testing companies for autosomal testing are of course FamilyTreeDNA, 23andMe, Ancestry and Helix. There are others but these are the more common ones.
Y Chromosomal or Y-DNA Testing
A Y chromosome DNA test or more commonly known as Y-DNA test, is primarily a genealogical test that is used to determine a direct male (more specifically your father's) patrilineal or direct male line of ancestry. Certain identified ySTR markers that are tested by the DNA testing company are given a particular numerical value. Those values are compared to the values of another tester cousin to see if any mutations occurred over generations of time, causing a difference in value in any of those markers between the two testers' results. It cannot be used to test your mother's father's line etc. It is only used to test a direct male lineage which means if you are not a male you will need to test a brother, father, paternal uncle, paternal male cousin etc of the line you are researching.
What will it tell me? You can visit this page for more technical background but in short, this test is beneficial in determining how closely one tester is related to another cousin tester. For example, hypothetically let's say Bob "Sproule" tested 67 STR markers and Jim "Sproull" tested 111 markers at FTDNA because they belong to the Sproul Project Group and they know they can compare their results on the Group Project Chart. Both Bob and Jim find out that they match enough markers at the 67 marker level that their most recent common ancestor (MRCA) was approximately eight generations back.
For those of us trying to find close cousins to collaborate with this is an incredibly useful revelation, HOWEVER. There's always a however, isn't there? Some of us may have enough of a paper trail in our genealogy that we might be able to find out who that eighth generation ancestor was and could possibly be our link. The problem is, Bob tested 67 markers. To see if the eight generation MRCA estimate holds, Bob will need to test out to 111 markers and see if his number of matched markers to Jim remains the same. Bob may find out that there are other mutational differences in further markers that could put that MRCA back twelve, sixteen or even more generations back.
How the mutations in the STR markers work is like this. All variants of Sproul it would seem to this point are all descendants of one man, Walter Spreull of Dumbartonshire, Scotland, Cir. 1285. Walter passed on his ySTR markers on to his male issue nearly exactly the same markers as his. His issue then passes on those markers to their male issue an so on, and so on up to today. What happens is the STR markers tend to mutate over a period of generations, some markers are very stable and hardly ever mutate and some are not so stable and can mutate more frequently.
The more markers the male tests is a greater level of confidence revealing whether you share the same STR values, mutations and all. The more you share the same values the closer you are as a cousin and share the same branch of Sprouls. This is the primary focus of the Sproul DNA group. We want to determine who we share the most STR markers with the same exact value. The more you share the closer you are related.
The ySTR test is basically a qualifier test to see who you are closely related to. The next step requires testing for SNPs (pronounced "snips") to establish individual branches of Sprouls that can give us a timeline as to when that branch occurred. This is important because this can link us to a specific branch in Scotland, Ireland etc to help narrow down our focus of research. I will cover SNP testing in a near future post.
There are basically only two companies that are currently testing ySTR markers, FamilyTreeDNA being one of them, which includes HeritageDNA as they have their tests done at the FTDNA lab in Houston, Texas. If you believe you have tested with the now defunct ySTR DNA testing companies such as RelativeGenetics, Genetree or Ancestry (all bought out by Ancestry) prior to 2014 you may likely have ySTR results from one those companies.
If you would like more information about this test please comment below so we can create a dialog for others to follow along for information and clarity.
Autosomal Testing
According to ISOGG, the technical definition of autosomal testing is "Autosomal DNA is a term used in genetic genealogy to describe DNA which is inherited from the autosomal chromosomes. An autosome is any of the numbered chromosomes, as opposed to the sex chromosomes. Humans have 22 pairs of autosomes and one pair of sex chromosomes (the X chromosome and the Y chromosome).
Many of you I'm sure have seen the Ancestry commercial where the gentleman is dancing in his lederhosen because he was always told his ancestry was German until his Ancestry test told him his ancestry is really Scottish. Pop-quiz...what did he trade his lederhosen in for???
This is autosomal testing. This test is useful for determining your ancestral origins and what percentage breakdown of the regions or countries around the world your DNA comes from. Unfortunately it won't help us in determining who our closest cousins are for collaborative research. It is useful in determining cousins from all sides of your family that have also autosomal tested, up to a point. Through a process called "recombination" it becomes unreliable after 5-6 generations. For more information on this type of testing please visit this informative, less technical background on autosomal testing.
Some of the more popular testing companies for autosomal testing are of course FamilyTreeDNA, 23andMe, Ancestry and Helix. There are others but these are the more common ones.
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