What can we assume about the geographic origin of the common ancestor of J2b-YP91 who lived about 4300 years ago, now that we know or strongly believe that its parent J2b-Z622 had been living among the Yamnaya in Moldova and perhaps southern Ukraine?
Well, I think we should consider the case that it may also have originated in southern Ukraine.
To begin with, we are lucky to have some ancient J2b-YP91 samples to also take into account.
Ancient J2b-YP91 Samples
On Flor Veseli’s J2b-L283 Ancient DNA map above, I’ve highlighted the two ancient J2b-YP91 samples we know about on the continent of Europe.
The oldest one at 450 BCE is from Sveti Križ, Croatia and the later one dates to 900 CE Vörs, Hungary. While these samples are not nearly old enough to prove an Early Bronze Age origin, the sample from Sveti Križ at least dates to before the large scale population movements associated with the Roman Empire and the later Migration Period.
We should also note that these two particular ancient samples are 4100 years distantly related. So they don’t represent a significantly later migration from a single common ancestor. Therefore we can consider that the approximate region around these two 180km distant by walking samples exhibits high diversity for ancient J2b-YP91 sampled so far.
However I think we cannot exclude Ukraine as the origin. After all, J2b-Z600 was also found in Bronze Age samples from Mokrin, Serbia and later in Croatia, yet was eventually proved to have originated in Moldova / Southern Ukraine from the recently found 2400 BCE ancient sample 103750 from Constantinovca, Moldova.
Lack of Ancient J2b-YP91 from Ukraine (so far*†) doesn’t count against Ukraine as Origin
Applying simple math to small data can yield limited, yet objective information
HRAS shows me that there were only 3 ancient Y-DNA samples found in Ukraine during the period of 2500 BCE to 1 AD.
Doing a little algebra we can actually derive some useful information, even with small data.
0.5 = (1-x)^n where x is the true relative frequency of target haplogroup and n is the total number of ancient samples found in an areaSolving for x gives us the true relative frequency such that it would be equally likely to observe zero positive samples vs one or more positive samples given n total ancient samples.
In this case, x is about 21%. So if the true frequency of J2b-YP91 in ancient Ukraine were 21%, it would be equally likely to observe zero vs one or more positive samples out of a sample size of three.
If the true frequency of J2b-YP91 in ancient Ukraine were under 21% (which I think we believe is true beforehand), then given a sample size of three, we should expect zero samples to be positive for J2b-YP91 rather than 1 or more positive samples.
So in the case of J2b-YP91, having zero ancient samples yet found in Ukraine does not count against Ukraine possibly having been the true origin. This type of simple calculation will become more meaningful once more ancient samples have been found in southern Ukraine and Moldova.
For now we are simply talking about the absence of any indicator.
* Note that I’m using HRAS computed ancient sample totals for Ukraine because this is convenient – it’s automatically computed and updated about every month. If you have a more replete data set than what is on the YFull YTree you can apply the same formula and draw sharper conclusions.
† Also note that the manner in which ancient samples are ‘selected’ is not completely random. Usually multiple samples are sequenced from the same site. This bias could be mitigated by excluding samples related to one another within a certain number of years from the counts.
Late Avar Elite VPB-307 May Have Come from the East
Another interesting possibility is that the 900 CE Vörs, Hungary sample’s male line ancestors may have accompanied the Avars to Hungary from a homeland further east, possibly in Ukraine where Avars are known to have been living.
This sample has a 600 BCE common ancestor with living men tracing descent to Lubelskie Poland and Vinnytsia, Ukraine. Vinnytsia lies within the area of the Catacomb Culture, a successor culture of the Yamnaya that encompassed areas east and west of the Core Yamnaya zone, from the Lower Danube to the Lower Volga. We don’t have proof that this sample from Vinnytsia is a remnant, but we can take his ancestry into account to perhaps better understand the likely bigger picture of J2b-YP91, the TMRCA of which falls within the range of the Catacomb Culture.
An Armenian from Kayseri Province is J2b-YP91>YP29+
One more potential tie to the east for this particular line of J2b-YP91 is the fact that a man of Armenian male line descent is YP29+ (YP181-), which has a 1400 BCE TMRCA with the aforementioned samples. He traces his ancestors to the town of Develi, formerly known as Everek, in Kayseri province of Turkey. This looks to be on the very eastern periphery of the Phyrgian dominions of Anatolia that the Cimmerians are known to have invaded in the 8th century BCE from their homeland in the steppes north of the Caucasus. If a J2b-YP91 migrated to Anatolia as a Cimmerian, then he most likely would have been a Cimmerian whose male line ancestors had been local to the North Caucasus steppe during the 9th century BCE formation of the Chernogorovka-Novocherkassk complex (commonly called “Cimmerian”) that saw a migration to the area of Iranian language speakers from an origin further to the east.
I’ve just ordered the YP38 SNP test at YSEQ for this Armenian sample in order to better understand his relationship to his aforementioned next-closest relatives.
1150 BCE ORC007 from Sardinia doesn’t count against a much more eastern homeland for J2b-YP91 in 2300 BCE
It must also be taken into account that the oldest ancient sample yet found positive for J2b-YP91 dates to 1150 BCE and is from Sardinia. It would be a curveball for a more eastern origin in the North Pontic steppe were it not for the fact that more prolific sibling J2b-Z600, which has also been found in ancient Sardinia, has been confirmed by the aforementioned ancient 2400 BCE sample to have likely originated in or around Moldova.
These posts are the opinion of Hunter Provyn, a haplogroup researcher in J-M241 and J-M102.