Cytogenetic comparison and phylogeny of three species of hylobatidae

Abstract

Representatives of three subgenera of Hylobatidae, Hylobates (Symphalangus) syndactylus, H. (Nomascus) concolor and H. (Hylobates) agilis were compared karyotypically by G‐banding, C‐banding, and silver staining. A greater degree of similarity (30–55%) was found among these groups than previous reports suggest; however, these figures are still considerably lower than chromosome similarities characteristic of all other catarrhine groups. Inversion, translocation, fission, and fusion have all played a role in restructuring hylobatid chromosomes since a common hominoid ancestor. H. syndactylus and H. concolor show the greatest G‐band correspondence, and in addition share an unusual C‐band distribution and an extremely rare nucleolar organizing region placement (on the Y chromosome). The latter two are probably shared derived traits, suggesting that these two species shared a common ancestor not shared by other hylobatids. These data sugest a branching order for these three hylobatid groups different from those derived by other morphological and biochemical methods.