Phylogeny of Y-chromosome haplogroups and their frequencies (%) in Marsh Arab and Iraqi populations. Haplogroups are labelled according to the Y Chromosome Consortium [17, 18] and the International Society of Genetic Genealogy . Differently from previously reported , the M365 mutation was observed in two J1-Page08 Y-chromosomes (Marsh Arabs). In these two subjects, M365 was observed in association with the new mutation L267.2 discovered while typing the M365 marker. It consists of an A to G transition at nucleotide position 159. The markers P37, M253, M223 of haplogroup I, M81 and M293 of haplogroups E, and M367, M368 and M369 of haplogroup J1 were typed but not observed. A star (*) indicates a paragroup: a group of Y chromosomes not defined by any reported phylogenetic downstream mutation. nt: not tested. (a) Heterogeneity.