Phylogeny and Evolution of Body Size in Caviidae (Rodentia, Hystricognathi, Cavioidea): Approach of a Combined Analysis with Morphology and Molecular Data

PÉREZ, M. E.; BASSO, N.G.; HOLLEY, A.; PATTERSON, B.D.; WEKSLER, M

Philadelphia

Congreso; 93rd Annual Meeting American Society of Mammalogists; 2013

American Society of Mammalogists

Caviidae forms part of the highly diverse South American hystricognath rodents and includes 3 major living lineages: Caviinae (cavies), Dolichotinae (maras), and Hydrochoerinae (capybaras and rock cavies). Caviids have the broadest range of body sizes among extant rodents, but so far the evolution of body size has never been properly analyzed in this group. In this contribution, we include new sequences of 4 genes (CoII, 16S, Rag-1, Vwf) for extant caviids and integrate them with published sequences of 4 other genes (cyt b,12S, Tth, Ghr) as well as a recently published morphological dataset scored for extant and extinct taxa (including the extinct "eocardiids," which form the successive sister groups of Caviidae). The resultant topologies are used to infer the evolution of body size in this group through the optimization of body mass estimates. The analysis reveals static body size across “eocardiids” and a much more dynamic history of body size changes within the crown group Caviidae. Hydrochoerines and dolichotines both increased in size but through 2 independent and temporally separated transitions. In turn, caviines reduced their body size during the middle-late Miocene, as major environmental changes were altering the South American biomes. This research was supported by an Oliver P. Pearson Award awarded to Maria Encarnacion Perez in 2012.b,12S, Tth, Ghr) as well as a recently published morphological dataset scored for extant and extinct taxa (including the extinct "eocardiids," which form the successive sister groups of Caviidae). The resultant topologies are used to infer the evolution of body size in this group through the optimization of body mass estimates. The analysis reveals static body size across “eocardiids” and a much more dynamic history of body size changes within the crown group Caviidae. Hydrochoerines and dolichotines both increased in size but through 2 independent and temporally separated transitions. In turn, caviines reduced their body size during the middle-late Miocene, as major environmental changes were altering the South American biomes. This research was supported by an Oliver P. Pearson Award awarded to Maria Encarnacion Perez in 2012.