Radiation and speciation of spider monkeys, genusAteles, from the cytogenetic viewpoint

Abstract

The chromosomes of 22 animals of four subspecies of the genus Ateles (A. paniscus paniscus, A. p. chamek, A. belzebuth hybridus, and A. b. marginatus) were compared using G/C banding and NOR (nucleolar organizer region) staining methods. The cytogenetic data of Ateles in the literature were also used to clarify the phylogenetic relationships of the species and subspecies and to infer the routes of radiation and speciation of these taxa. Chromosomes 6 and 7 that showed more informative geographic variation and the apomorphic form 4/12, exclusively in A. p. paniscus, are the keys for understanding the evolution, radiation, and specification of the Ateles taxa. The ancestral populations of the genus originated in the southwestern Amazon Basin (the occurrence area of A. paniscus chamek) and spread in the Amazon Basin and westward, crossing the Andes and colonizing Central America and northwesternmost regions of South America. The evolutionary history of the northern South American taxa is interpreted using the model of biogeographical evolution postulated by Haffer [Science 185:131–137, 1969]. Ateles paniscus paniscus is the genetically most differentiated form and probably derives from A. belzebuth hybridus. Based on the karyotype differences, the populations of Ateles can be divided into four different group. These findings indicate the necessity of a more coherent taxonomic arrangement for the taxa of Ateles. Am. J. Primatol. 42:167–178, 1997. © 1997 Wiley‐Liss, Inc.

An assessment of the diversity of New World primates

“…In their review of the taxonomic status of Guatemalan spider monkeys they concluded that 1) the coloration pattern of A. g. vellerosus includes a broader spectrum of color and tones than was previously considered; 2) A. g. yucatanensis may be considered a valid taxon, but only after more evidence can be obtained from several localities in the known geographical range of the subspecies; and 3) based on the available evidence (maps, vegetation types, and existing records) and supporting the observations of Konstant et al (1985) that A. g. pan is probably merely a variation of the highly variable A. g. vellerosus. Medeiros et al (1997) confirmed the conclusions of Froehlich et al (1991) in indicating that the forms marginatus (E. Geoffroy, 1809) and chamek (Humboldt, 1812) should be considered subspecific to A. belzebuth, and that hybridus I. Geoffroy, 1829 is better placed as a subspecies of A. geoffroyi. Medeiros et al (1997) indicate, however, that from the cytogenetic viewpoint rufiventris Sclater, 1871, may well be reproductively isolated, although a hybrid zone between this form and A. g. panamensis was reported by Rossan and Baerg (1977).…”

“…Medeiros et al (1997) confirmed the conclusions of Froehlich et al (1991) in indicating that the forms marginatus (E. Geoffroy, 1809) and chamek (Humboldt, 1812) should be considered subspecific to A. belzebuth, and that hybridus I. Geoffroy, 1829 is better placed as a subspecies of A. geoffroyi. Medeiros et al (1997) indicate, however, that from the cytogenetic viewpoint rufiventris Sclater, 1871, may well be reproductively isolated, although a hybrid zone between this form and A. g. panamensis was reported by Rossan and Baerg (1977). Collins (1999aCollins ( , 1999bDubach, 2000a, 2000b) argued strongly for the species status of the form hybridus I. Geoffroy, 1829, but otherwise agreeing with the classification proposed by Froehlich et al (1991).…”