Y-Chromosome DNA (Y-DNA)

Y-chromosome DNA is passed down almost entirely from father to son. In theory, a father and son should have an identical Y-chromosome, but in nature, random copying errors occur. These errors cause the replacement of individual nucleotides (bases A, T, C, or G), which creates a new genetic variant or mutation.

It is precisely these genetic variants that form the basis for genetic genealogy. Because certain groups of men share the same mutations, they are classified into so-called haplogroups. When a geneticist confirms that at least two individuals share the same specific variant, a new branch is determined on the global family tree. Haplogroups are named with the letter of the main line (e.g., R, I, J...) and the code of a specific mutation (SNP), which represents a specific point in the DNA chain where the change occurred (e.g., R-Y1382).

Y-DNA Haplogroup Tree

These genetic variants allow for the construction of a genetic genealogical tree of haplogroups. An example of such a tree is the Paternal Line (Y-DNA) display on the Slovenian Genetic Heritage page.

Below is the Y-DNA haplogroup tree, showing the placement of my oldest ancestor on the paternal line: Jakov / Jakob Renka (b. 1764).

The first assigned haplogroup was R-Y1392, which was estimated based on the atDNA test. The common ancestor of this group is estimated to have lived around 314 BC.

A more precise analysis using the Big-Y 700 test at FamilyTreeDNA revealed a much more recent haplogroup, R-Y35453, whose common ancestor is estimated to have lived around 721 AD.

Migration Path of My Ancestors

One of the most fascinating possibilities of Y-DNA testing is tracing migration paths from the so-called "Y-chromosomal Adam" to the present day. With the help of archaeogenetics (analysis of remains from archaeological sites), we can estimate where my ancestors moved across the millennia.

The video above shows the migrations undertaken by my paternal ancestors before they settled in the present-day area. These are, therefore, those "early Slavs" who brought their heritage to our lands in their genes (as sung by Zoran Predin in his famous song).

Finding Relatives on the Paternal Line

Similar to autosomal tests, Y-DNA testing involves looking for matches with other test-takers. The difference is that a Y-DNA match means the two individuals share a common ancestor exclusively along an unbroken paternal line.

So far, I have discovered a close relative whose ancestors originate from Predmeja near Ajdovščina, but who now lives in the USA. We share a common male ancestor from 721 AD (R-Y35453). This roughly coincides with the period of the arrival of the Slavs in our territory. Although we have different surnames (Velikonja and Renko), this is not unusual, as permanent family surnames were established in our region much later.

I also share an ancestor (around 569 AD) on the R-BY32501 haplogroup with three other people from Slovenia and Italy. One of their descendants is a fellow genealogist at SRD.

Through Y-DNA matches, I have thus met distant cousins. We couldn't confirm our connections through genealogical research in parish registers, but our kinship was confirmed by Y-DNA analysis.

Private Variants (SNPs)

An important piece of information from the Big-Y test is the so-called Private Variants. These are mutations that are currently confirmed only in my DNA.

I currently have 8 private variants. These are genetic variants waiting for someone else with the same mutation to be tested, which would allow the definition of a new, even younger haplogroup that I would share with this person.

Further Research

My next goal is to test the most distant male relative possible from the Renko/Renka line. If this person were tested, their results would help "convert" my private variants into an official haplogroup. This would bring the genetic tree closer in time to the period between 1000 and 1500 AD. This would be a crucial bridge between the genetic findings and my written sources, which go back to around 1600.

I also want to research other paternal lines in my family tree (e.g., Rakar, Jekovec, Pezdirc). For these lines, I first need to identify living male descendants and encourage them to test. To start, a basic Family Finder or Y-DNA test (e.g., Y-37) would be suitable to confirm the line, followed by a potential upgrade to Big-Y 700 for precise placement on the timeline.