The population history of J is too complicated but R1a is a more recent phenomenon. Haplogroup J is not semitic in origin, they spoke language isolates.
https://2.bp.blogspot.com/-0u2IraQPB...-hg_R1a_v2.jpg
10,000 years of bleaching the middle east.
https://i.imgur.com/MwMiVOi.jpeg

