Introduction Diversification of feeding strategies within each of the 19 chiropteran families (Hoofer and Van Den Bussche, 2003; Van Den Bussche and Hoofer, 2004; Simmons, 2005) typically is limited to one (13 families) or two (five families) food sources. The family Phyllostomidae, however, represents an exception to this pattern with six distinct feeding strategies: sanguivory, insectivory, frugivory, nectivory, carnivory (feeding on vertebrates) and omnivory. Among families of bats, phyllostomids comprise the largest number of genera (56) and the third largest number of species (160+) (Simmons, 2005). They are distributed throughout tropical and subtropical regions of North and South America and have been highly successful in exploiting a diverse array of life-history strategies. Included among its members are three species of obligate sanguivores, a feeding strategy unknown in vertebrates other than fish (Figure 11.1). Among phyllostomids additional examples of feeding specialization exist, including subsisting exclusively on insects, as well as primarily on fruit, nectar, frogs, rodents and other vertebrates. Such specializations are remarkable when viewed in the context of the concomitant suite of adaptations associated with the sensory apparatus, locomotion, digestion, dentition, kidney function and reproduction, among others (Griffiths, 1982; Greenhall and Schmidt, 1988: Fleming et al., 2005) that must be favored by directional natural selection for successful exploitation of new ecological opportunities. No other clade of mammals with roots in the Eocene displays such radical evolutionary modifications.

We document the first confirmed Colombian records of Myotis keaysi pilosatibialis LaVal, 1973 from various localities on the Colombian Caribbean and the Eastern Cordillera of the Colombian Andes. These records confirm geographic overlap between M. k. pilosatibialis and the nominate subspecies M. k. keaysi J. A. Allen, 1914, in northeastern Colombia, questioning the subspecific status of M. k. pilosatibialis. Models of potential distribution, produced for the two taxa by the application of the Maxent algorithm, show a potential geographic overlap in the northeastern portion of the Andes of Colombia and Venezuela. In order to clarify the taxonomic status of putative M. keaysi variants, we analyzed the variation of Colombian representatives of M. keaysi through a Principal Components Analysis (PCA), and a Discriminant Function Analysis (DFA) performed on 18 cranio-dental measurements, as well as the analysis of discrete characters. The morphological independence between M. k. keaysi and M. k. pilosatibialis was supported statistically in our PCA and DFA, as well as by the presence of unique discrete characters, lending support to the recognition of M. k. pilosatibialis as full species. Herein, we include new discrete characters setting apart M. pilosatibialis from the morphologically similar species M. keaysi.

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The Biodiversity Heritage Library works collaboratively to make biodiversity literature openly available to the world as part of a global biodiversity community.

Diversidad, abundancia relativa y patrones de actividad de los mamíferos medianos y grandes, asociados a los bosques riparios del río Bita, Vichada, Colombia

Morphological evolution can be the result of natural selection favoring modification of developmental signaling pathways. However, little is known about the genetic basis of such phenotypic diversity. Understanding these mechanisms is difficult for numerous reasons, yet studies in model organisms often provide clues about the major developmental pathways involved. The paired-domain gene, PAX9, is known to be a key regulator of development, particularly of the face and teeth. In this study, using a comparative genetics approach, we investigate PAX9 molecular evolution among mammals, focusing on craniofacially diversified (Phyllostomidae) and conserved (Vespertilionidae) bat families, and extend our comparison to other orders of mammal. Open-reading frame analysis disclosed signatures of selection, in which a small percentage of residues vary, and lineages acquire different combinations of variation through recurrent substitution and lineage specific changes. A few instances of convergence for specific residues were observed between morphologically convergent bat lineages. Bioinformatic analysis for unknown PAX9 regulatory motifs indicated a novel post-transcriptional regulatory mechanism involving a Musashi protein. This regulation was assessed through fluorescent reporter assays and gene knockdowns. Results are compatible with the hypothesis that the number of Musashi binding-elements in PAX9 mRNA proportionally regulates protein translation rate. Although a connection between morphology and binding element frequency was not apparent, results indicate this regulation would vary among craniofacially divergent bat species, but be static among conserved species. Under this model, Musashi’s regulatory control of alternative human PAX9 isoforms would also vary. The presence of Musashi-binding elements within PAX9 of all mammals examined, chicken, zebrafish, and the fly homolog of PAX9, indicates this regulatory mechanism is ancient, originating basal to much of the animal phylogeny.