Abstract # 79:

Scheduled for Saturday, September 17, 2011 07:00 PM-09:00 PM: Session 14 (Salon G (Sixth Floor)) Poster Presentation


DID THE EXTINCTION OF LARGE SPECIES ALTER THE PHYLOGENETIC STRUCTURE OF MALAGASY PRIMATE ASSEMBLAGES?

O. H. Razafindratsima, S. Mehtani and A. E. Dunham
Rice University, EEB Department - MS 170, Houston, Texas 77005, USA
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     We tested the hypothesis that recent extinctions of large bodied Malagasy primates during the Holocene resulted in the current overdispersed pattern of phylogenetic and trait structure of current communities. Species composition was gathered for 44 Extant and 18 Holocene communities. Holocene communities were recreated from archeological findings. A phylogenetic tree was constructed for this study including 68 extant species and 16 extinct species. We measured the relative phylogenetic distances and trait structure with the program Phylocom. The majority of both extant and Holocene communities were found to be phylogenetically overdispersed with species more distantly related than expected by chance. The extinction of large species thus does not seem to be responsible for the difference in phylogenetic structure of the Malagasy primate assemblages. Trait structures of the communities, however, were affected by extinctions. Species in the Holocene communities showed greater divergence in body mass than expected by chance, while body size within the extant communities were random. This difference may be due to the selective hunting of large species by early Malagasy settlers that resulted in their extinction. Interestingly, the diet assemblage in the Holocene communities was no different than random which differs from the divergent diet composition of the extant communities. Perhaps the larger body size of the extinct species allowed frugivores and folivores to exploit different niches within their guild reducing competition.