Showing posts with label haplogroup. Show all posts
Showing posts with label haplogroup. Show all posts

Sunday, January 11, 2015

Genographic Project: Deep Ancestry

This is part two of my exploration of the Genographic Project's Geno 2.0 kit submitted by my paternal uncle.  (Prior post:  Regional Ancestry.)

In this post, I discuss Deep Ancestry, the term used by the Genographic Project to describe the information gleaned from haplogroups, which are determined by the Y chromosome ("Y-DNA") and the mitochondrial DNA ("mtDNA").

These types of DNA are useful for both anthropology and genealogy because they pass from generation to generation almost unchanged along prescribed paths of inheritance (father to son for Y-DNA and mother to children for mtDNA).  From an anthropological viewpoint, haplogroups based on Y-DNA and mtDNA reveal the migratory paths of humans across the globe from the beginning of civilization, hence the squiggly arrows on the world map below.  For us genealogists, Y-DNA and mtDNA testing can prove or disprove a genetic relation on a particular ancestral line.



My uncle's haplogroup designations through Geno 2.0 were R-Z36 for his paternal line (Y-DNA) and K1 for his maternal line (mtDNA).  These are common European haplogroups.

These haplogroup designations were interesting because they were already measured in some manner by prior DNA testing of the family.  We'll look at the paternal haplogroup first.


Paternal haplogroup of uncles (and maternal cousins) at 23andMe


Paternal haplogroup of Jody's father at 23andMe



23andMe offers autosomal DNA ("atDNA") testing, not Y-DNA; however, you will receive predictions about your haplogroups.  (Women do not have a Y chromosome, so they will not receive a paternal haplogroup prediction.  A woman's DNA matches at 23andMe are based on autosomal DNA, which comes from both of her parents.)  My father tested at 23andMe four years ago.  His siblings tested two years ago.  My father's predicted paternal haplogroup is R1b1b2a1a2d*.  His brothers tested as R1b1b2a1a2d.  The difference is with the *asterisk*.  All three brothers should have had the same exact result.  According to a customer care page at 23andMe, the *asterisk* indicates that the haplogroup does not fit into any further subgroups.  It is possible that a brother has a mutation and the other does not.  Another factor may be that the testing process slightly differed two years later, when the brothers submitted their samples.  (This is one of the reasons why I caution people to disregard haplogroups when analyzing their matches at 23andMe.)

Also of note:  two of my father's maternal cousins tested at 23andMe.  They received the same paternal group prediction as my father's brothers.  This is a coincidence, as they do not share the same paternal line.

The best way to determine a Y-DNA match for genealogy is through testing at FamilyTreeDNA.  On the webpage of the Genographic Project was a link to upload results from Geno 2.0 to FamilyTreeDNA- for free!  So I did.  My father and his maternal cousin have already tested their Y-DNA at FamilyTreeDNA.





Y-DNA haplogroup for my paternal uncle at FamilyTreeDNA based on results transferred from Geno 2.0

(Haplogroup designations at FamilyTreeDNA and the Genographic Project are abbreviated.)

Y-DNA haplogroup (R-M269) for my father at FamilyTreeDNA.  37 marker test.

FamilyTreeDNA shows a deeper subgroup for my father's brother than for my father.  I do not know the scope of the Y-DNA test of Geno 2.0.  The website reads, "The genetic technology we use for our testing is a custom-designed genotyping chip optimized for the study of ancestry, with far more Y-chromosome and mtDNA markers than are available with any other test."  I don't know, at this point, if the difference in haplogroups is because of testing variation or if one brother has a mutation that the other does not.


Y-DNA haplogroup (R-P312) for my father's maternal cousin at FamilyTreeDNA.  37 marker test.
To illustrate the contrast of the 23andMe haplogroup designation with FamilyTreeDNA, note that 23andMe placed my father's maternal cousins in the same haplogroup as my father's brothers.  Y-DNA testing of one of these cousins places him into a different subgroup from both my father and his brother.

Uploading to FamilyTreeDNA from Geno 2.0 did not allow for matching with others.  (My father's test allows for matching to others, but there are none.  To see men with a common ancestor on their direct paternal line, go to my post about my cousin's matches.)

Next is the mtDNA haplogroup.  Geno 2.0 assigned haplogroup K1 to my uncle.  23andMe assigned my uncle and all of his siblings to a subgroup, K1c2.


Reflecting back on earlier testing, in the year 2010, my paternal aunt tested simply as haplogroup K at Ancestry.com.  Ancestry no longer offers mtDNA and Y-DNA testing.


I have not tested anyone's mtDNA at FamilyTreeDNA because the results are likely not genealogically relevant.  Mitochondrial DNA mutates at a much slower rate than Y-DNA.  A "match" in mtDNA may go back thousands of years, before written records.

Friday, August 3, 2012

Not so Black and White

DNA and genealogy has made national headlines!

President Barack Obama is descended through his "white" mother from one of the first African slaves in Virginia, John Punch.  The report was issued by Ancestry.com, which you can read here.  Then head over to The New York Times article by Sheryl Gay Stolberg.  The line of descent was established through document-based research as well as Y-DNA testing.  Let me explain.

President Obama's Y-DNA was not tested for this proclamation.  If you are not a direct male descendant of the ancestor in question, you need a relative who is a direct male descendant to take the Y-DNA test.  The President's line of descent from John Punch is through his mother, so we know right away that the direct male line from John Punch to President Obama was broken somewhere.

Biology lesson:  You have 23 pairs of chromosomes- one from each parent.  The 23rd pair determines sex.  Women have XX as their 23rd pair while men have XY.  The Y chromosome passes from father to son almost unchanged.  This is useful in genealogy for tracing direct male lines, especially because children in the United States usually use the surname of their father.  This is why only a man can take a Y-DNA test and why you see Surname Projects.  [For clarification, males and females can take autosomal DNA tests to capture DNA inherited from all ancestors.]

The New York Times article introduces us to Mark Bunch, a "fifth cousin twice removed" of the President.  Fifth cousins have a common set of 4th great grandparents.  "Twice removed" means that one line is two generations earlier or later than the other.  Follow the link provided by the New York Times and you will arrive at the Y-DNA chart for the Surname Project Bunch.  [John Punch's descendants altered the name to Bunch.]  Y-DNA is categorized into haplogroups based on the migratory patterns of humans tens of thousands of years ago.

The top haplogroup for Bunch is E1b1a, which is found predominantly in Africa, hence the claim that President Obama has African descent through his mother.  Most participants at the Bunch Y-DNA site share almost identical Y-DNA.  A mutation can occur in any generation.  Over time, when enough mutations occur, a new haplogroup arises; hence, we are able to trace migratory patterns of humans for hundreds of thousands of years.

The E1b1a African paternal haplogroup of direct male descendants of John Punch is consistent with written records that he was of African origin.  Conversely, you can be of African origin but have a "European" haplogroup.  The haplogroup is determined by one line of ancestry only and tells us nothing about any other ancestor.

The nearly identical results of analysis of the participant's Y-DNA indicates that all of their direct paternal lines merge at some point back in history.  Each participant lists the most distant direct male ancestor, which is discovered by document-based research.  Please note in the Bunch Y-DNA chart names of ancestors whose surname was not Bunch.  This can be caused by children not carrying their father's surname, or a name change, or a "non-paternal event."

To trace back to a Bunch ancestor in President Obama's line, you must travel through six generations of women.  President Obama's most recent male ancestor with the surname Bunch was Nathaniel, born 1793 in Virginia, and died 1859 in Arkansas.  The President is descended through Nathaniel Bunch's daughter, Anna, hence breaking the Y-DNA path.  To obtain the Y-DNA of this Bunch line, we need to turn to a direct male descendant along this same line.  Mark Bunch, the President's fifth cousin twice removed, is descended from Nathaniel Bunch's brother Charles Bunch down a direct male line and thus carries the Bunch Y-DNA.  Charles Bunch and Mary Bellamy, the parents of Nathaniel and Charles, were the most recent common ancestors of President Obama and Mark Bunch.  This couple was the 4X great grandparents of Mark Bunch and the President's maternal grandmother, making Mark Bunch and the President fifth cousins, twice removed.  [Note:  Mark Bunch confirmed this relation in an email to me.]