One of the main concepts of phylogeography is that if all or most men descending from a common ancestor trace their descent to the same place, there is a reasonable chance that their common ancestor had been living there.
While this is a good general rule, there are many known instances where such a phenomenon must have been caused by comigrations of related men that happened after their most recent common ancestor lived. One reason for migration is that the original homeland could no longer support the population or they were driven away by invaders or their own people. If the lines that remained in the original homeland died out, all we have left are the descendants of migrants that went somewhere where their male lines ended up surviving.
Separate coincidental later migrations of very distantly related people to the same place can also happen. We see this a lot in people of English descent because so many of them test today. If we are not careful we assume a deeper English origin of lineages that originated elsewhere, like some branches of my male line J2b-L283.
This is one line of J2b-M205 that is closely related to the oldest J2b-M205 ancient sample yet found, I1730 from Ain Ghazal, Jordan dating to about 2360 BCE. YFull uses 2015 as their present year, so the figure they use as the median age, 4377 subtracted from 2015 yields this approximate date.
Sibling J2b-PH3103 is also found in the Levant, but none of the guys who did NGS testing or 111 STRs in J2b-Y128487 are from the Levant.
The men who are J2b-Y128487 are from eastern Anatolia, Mosul, the Persian Gulf coast of Arabia, and there are several ethnic Armenians, one from the town of Salmas, just west of Lake Urmia.
I think the Zagros Mountains makes more sense than the Levant as the ancient homeland of J2b-M205 because this is where the oldest samples of J2b (though from other lineages) have been found and J2b-M205 has high diversity in the Persian Gulf and around the Zagros Mountains. Ancient samples would need to be found to confirm this.
If J2b-M205 itself and/or many of its child lineages did originate near the Zagros, then the modern samples from Mosul and Salmas may be the best indication of this deeper origin. They would be more likely than others to be remnants indicative of the approximate ancient origin.
Two men from Mosul
The first Mosul sample who tested is a Chaldean and I believe from context of my email correspondence is a Christian (if not him, then some of his male line relatives). He has a close male line relative tracing descent to Shaqlawa.
A second man from Mosul, distantly related, is not Chaldean but an Arab Muslim (or his male line ancestor is/was, I do not yet know how many generations back this identity traces back to).
In order to advance the research into the deeper origins of J2b-Y128487 and by association, J2b-M205, I decided to pay to upgrade the second sample from Mosul to Big Y in order to determine if my prediction is correct - that they are each others' closest relatives and might descend from a MRCA that lived around 3000 or more years ago.
There is no reliable way to predict such a TMRCA from their STRs but they only have a few rare alleles in common and are otherwise about as divergent from each other as they are to the other J2b-Y128487 men. So this is why I think their TMRCA may be nearly as old as the J2b-Y128487 TMRCA itself, which YFull v9.05 estimates as 3700 ybp.
The outskirts of what is now Mosul was once Nineveh, the capital and largest city of the Neo-Assyrian empire. If these two men from Mosul form their own new line of J2b-Y128487 it could be indicative that their MRCA had been living in that region for thousands of years, maybe even dating to one of the earlier Assyrian kingdoms.
The older their MRCA, the more useful their data point is for reckoning the ancient origin of J2b-Y128487. A researcher who I believe is from Iraq has offered to pay for the YFull analysis. I bought the Big Y upgrade with my own money, plus a $10 donation from someone in this haplogroup.
I am not independently wealthy and if you value this research and wish to help reimburse me your donation will be much appreciated - https://www.paypal.me/phylogeographer