Haplogroup J-M304 is believed to have split from the haplogroup I-M170 roughly 43,000 years ago in Western Asia, as both lineages are haplogroup IJ subclades. Haplogroup IJ and haplogroup K derive from haplogroup IJK, and only at this level of classification does haplogroup IJK join with Haplogroup G-M201 and Haplogroup H as immediate descendants of Haplogroup F-M89. J-M304 is defined by the M304 genetic marker, or the equivalent 12f2.1 marker. The main current subgroups J-M267 and J-M172, which now comprise between them almost all of the haplogroup's descendant lineages, are both believed to have arisen very early, at least 10,000 years ago. Nonetheless, Y-chromosomes F-M89* and IJ-M429* were reported to have been observed in the Iranian plateau (Grugni et al. 2012).