Voltage,
J2 is Anatolian and more common in Greece and Southern Europe than it is in the Middle East. I think you meant J1 and that haplogroup has been in Africa since the Neolithic just like R1. It’s not a newcomer. You might argue that coastal Somalis who carry it are descendants of migrants but how do you explain some Garres in deep K5 and Omotics in remote areas of Ethiopia carrying it?
Also Haplogroup J is from the Caucasus mountains while R is from the Eurasian steppes.
X.Playa,
Who are these Ischaqs mentioned in the first source?
Thanks for the correction. Yes, J1.
Also I can think of a very quick theory with the Garre or an Oromo or any non-Semitic speaking Ethiopian who may have J.
Historical rape.
Just like a large chunks of African Americans have European Y-DNA (we all know their Black fathers did not come from the British isles) because of rape by White men on Black women, similarly we can look at Ethiopia to see
1. The country has the only indigenous Black Semitic-speakers (Amharic, Tigrinya, rtc)
2. The country also consistently tests 20-25% J1-carriers.
3. The Semitic-speaking J carriers were also the historically dominant/oppressive group.
4. You cannot rule out what effect rape and genetic displacement has had from those historicallt dominant Semitic speaking J-carriers on small pockets of people within larger groups.
Again I refer you to the African-Americans who
Many African-Americans, when they perform Y-DNA testing, discover that their Y-chromosome is of European origin. This has been attributed to the common practice among slave-owners of fathering children by their female slaves.
Any existence of J1 outside of the indigenous Semitic-speakers in Ethiopia unless it corresponds to recent Arab admixture is in my estimatation a function of either historical rape or genetix displacement as a result of Abbysinian oppression.
This is over a thousand years so we also cannot rule out natural population reorganization like would happen if some Amhara group drifted to end up being "reorganized" within other populations in Ethiopia. After all, you love to stress the Cushitic-speaking Agew were completely adopted into the Amhara people. The inverse is also the case
In general,you shouldn't really bring up small subsections of groups when we are talking about averages.