Friday, April 26, 2013

Letters from our ancestors: Part 3

[This post was first published in February 2012; deleted red herrings and updated known paternal ancestry November 26, 2015 (confirmed by DNA match December 22, 2015).]
[Continued from Part 2. To start at the beginning, go to Part 1.]

Genetic cousins

When I refer to genetic cousins, I am generally referring to other people who have had their atDNA sequenced and with whom I share atDNA segment(s) that meet certain criteria used to identify matches that are identical by descent (IBD) rather than those that are identical by state (IBS), meaning identical by chance. We share common ancestors in recent history (within hundreds of years not thousands of years), even though we may not know exactly who they were. The further back we share an ancestor, the more diluted our shared DNA becomes and the harder it is to identify it. I currently have about 700 genetic cousins in my 23andMe Relative Finder list out of over 125,000 customers in total, i.e. less than 1% of the customer database. I also have over 100 genetic cousins in Family Tree DNA's Family Finder database, which is currently smaller than that of 23andMe. My closest genetic cousin to date is a predicted 3rd to 5th cousin.

23andMe customers will tell you that my number of genetic cousins is too low for someone with partial Ashkenazi Jewish ancestry, who typically has a relatively large number of genetic cousins due to historically endogamous practices resulting in DNA from multiple common ancestors being shared with other Ashkenazi Jewish customers. Less is currently known about the genetics of the smaller groups of non-Ashkenazi Jewish people in the US. Nevertheless I do have some Jewish genetic cousins, and some of them also share my family's original surname.

My Reinhardt cousins

In theory, Y-DNA and surname are inherited more or less unchanged over many generations down the direct paternal line (from father to son). However, this will not be the case regarding surname if there were any "non-paternal events" in this line, i.e. if a child's surname is not the same as that of the child's biological father. In my own family tree there are males who were adopted, whose surnames were changed and who were given their mother's surname at birth. Despite this caveat, Y-DNA results are used with some success by adoptees to obtain clues about the name of their biological father. A predominance of one surname among an adoptee's Y-DNA matches can provide an indication of the likely surname of their biological father.

Out of all the genetic cousins that have identified themselves to me to date (the friendly ones), three have a surname that is a spelling variation of Reinhardt and another three have the name in their list of ancestral surnames. They generally trace their Reinhardt lines back to Germany. This is a very exciting result for me, as I had never seen our original family surname in black-and-white before (I do realize that not all Reinhardts are related and that we may be related via different ancestral lines altogether, but I do not have such results with any other ancestral surnames). All three with the Reinhardt surname are male, which means that I may be able to infer information about my direct paternal line from their Y-DNA results.

All three of my genetic cousins with the Reinhardt surname have different Y-DNA haplogroups described below (J2, R1a1a and R1b1b2a1a2d3), which means that they cannot all be descended in a direct paternal line from a common Reinhardt ancestor. If they are all related via a common Reinhardt ancestor, some or all of them may be descended from their common Reinhardt ancestor via another ancestral line, e.g. via a mother with the maiden surname Reinhardt.

"Haplogroup: J2, a subgroup of J
Age: 18,000 years
Region: Southern Europe, Near East, Northern Africa
Populations: Ashkenazi Jews, Sephardic Jews, Lebanese
Highlight: Haplogroup J2 is found in nearly one-quarter of Sephardic Jewish men.
Overview: Haplogroup J2 is most common in southern Europe, Anatolia and the Caucasus, where it may have originated about 18,000 years ago. It appears to have spread into Europe in a number of waves over the course of millennia."
Paternal Haplogroup: J2, 23andMe

"Haplogroup: R1a1a
Age: 12,000 years
Region: Eastern Europe, Scandinavia, Southwestern Asia, India
Populations: Ukranians, Indians, Poles
Highlight: R1a1a is the most common haplogroup in eastern Europe.
Overview: R1a1a is the primary haplogroup of Eastern Europe, where it spread after the end of the Ice Age about 12,000 years ago. The haplogroup is most common in a swath from Ukraine and the Balkans north and west into Scandinavia, along the path of the men who followed the receding glaciers into Europe. It is also common near its presumed point of origin in south-central Asia."
Paternal Haplogroup: R1a1a, 23andMe

"Haplogroup: R1b1b2, a subgroup of R1b1
Age: 17,000 years
Region: Europe
Populations: Irish, Basques, British, French
Highlight: R1b1b2 is the most common haplogroup in western Europe, with distinct branches in specific regions.
Overview: R1b1b2 is the most common haplogroup in western Europe, where its branches are clustered in various national populations. R1b1b2a1a2b is characteristic of the Basque, while R1b1b2a1a2f2 reaches its peak in Ireland and R1b1b2a1a1 is most commonly found on the fringes of the North Sea."
Paternal Haplogroup: R1b1b2a1a2d3 (a subgroup of R1b1b2), 23andMe

The likely place of origin of the R1b1b2a1a2d3 subgroup of Y-DNA haplogroup R1b1b2 is generally considered to be Southern Germany.

My Reinhardt cousin with the haplogroup J2 is a member of a Y-DNA surname project, The Rinehart DNA Project, which has a wide variety of haplogroups in its Y-DNA results reflecting the reality of different Reinhardt lineages and non-paternal events. He does not have any matches there yet.

I have seen photographs of two of my genetic cousins with the Reinhardt surname and one of them could easily pass for my younger brother (who looks more like our father than our mother, and also closely resembles our older half-brother).

My European cousins

My 23andMe Ancestry Painting biogeographical ancestry results confirm that my ancestry is 100% European, which does not help me much (they only use three reference populations, i.e. Africa, Asia and Europe, due to reference population data constraints and because it is difficult to differentiate between DNA inherited from genetically similar populations). Fortunately I am able to zoom in a bit closer using 23andMe's Ancestry Finder tool which makes use of data submitted by my genetic cousins about their known ancestry. This tool provides clues about my ancestry by analyzing the known places of birth of the grandparents of my genetic cousins, bearing in mind that the data is influenced by 23andMe's customer footprint and by the extent to which customers complete their ancestry survey.

I have genetic cousins with all four grandparents born in the following European countries, listed in order of the percentage of my genome covered:

United Kingdom

The first three countries correspond with my known maternal ancestry, and the other countries provide clues about my paternal ancestry suggesting eastern European and/or Germanic ancestry.

Principal component analysis

Doug McDonald, a Professor of Chemistry at the University of Illinois, kindly analysed my 23andMe raw data using principal component analysis and advised: "My new program says that you are, with a passable fit, French. However, better is a fit with some combinations of Orkney, France, Spain, and Lithuania. Orkney/Jewish (83/16%) fits as well as plain French."

My Mideast component (5.8%) is a bit higher than the 5% benchmark used to identify Jewish ancestry, and indicates that something in my ancestry is pulling me in a south-easterly direction.

[Continued in Part 4.]

"I am the family face;
Flesh perishes, I live on,
Projecting trait and trace
Through time to times anon,
And leaping from place to place
Over oblivion.
The years-heired feature that can
In curve and voice and eye
Despise the human span
Of durance - that is I;
The eternal thing in man,
That heeds no call to die."
Thomas Hardy (1840-1928), Heredity