It is notable that no example of a Haplogroup IJ* Y-chromosome has been found among any modern human population; the existence of the Haplogroup IJ node has been inferred from the fact that certain mutations are shared in common among all Y-chromosomes belonging to the descendant haplogroups I and J. The lack of any examples of Haplogroup IJ* belonging to neither Haplogroup I nor Haplogroup J complicates any attempt to deduce the geographical location where Haplogroup IJ first appeared; however, the fact that both Haplogroup I and Haplogroup J are found among modern populations of the Caucasus, Anatolia, and Southwest Asia tends to support the hypothesis that Haplogroup IJ derived from Haplogroup F in the vicinity of West Asia or the Middle East and subsequently spread throughout Western Eurasia.