CLADISTICAL ANALYSIS OF G-BANDED CHROMOSOMES OF NECTAR FEEDING BATS (GLOSSOPHAGINAE: PHYLLOSTOMIDAE)

stained chromosomes, when analyzed in a cladistic framework, provide a systematic hypothesis for ten glossophagine genera. Two separate groups are recognized on the basis of chromosomal data; a chromosomally conservative or plesiomorphic group consisting of Glossophaga, Monophyllus, Leptonycteris, and the brachyphyllines, and a relatively rapidly evolving derived group consisting ofdnoura, Lonchophylla, Lionycteris, Choeroniscus, Choeronycteris, Hylonycteris, and Musonycteris. Among the six genera characterized as slowly evolving, only a single rearrangement has been identified, whereas, among the seven genera characierized as rapidly evolving over 100 chromosomal rearrangements are required to explain the observed variation. Such a contrast in rate and type of chromosomal evolution is difficult to explain in terms of most currently accepted theories,,of chromosomal evolution and the pattern of change is most like "karyotypic megaevolution. Within the derived group, cladistic relationships are resolved to the generic level. Variation in the magnitude of evolution at the morphological and chromosomal levels is such that chromosomal data are useful for the resolution of relationships among genera, whereas, morphological data are more informative at the subfamilial level. A combination of the two data sets is compatible with th