INVESTIGADORES
OJEDA Ricardo Alberto
artículos
Título:
Geographical distribution and ecological diversification of South American octodontid rodents
Autor/es:
AGUSTINA A OJEDA, AGUSTINA NOVILLO, RICARDO A OJEDA AND SERGIO A ROIG-JUÑENT
Revista:
JOURNAL OF ZOOLOGY (1987)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012 p. 1 - 9
ISSN:
0952-8369
Resumen:
Caviomorph rodents represent one of the most distinctive groups of mammals in
southern South America drylands; they colonized South America from Africa via
trans-oceanic dispersions in the Eocene (40?50 Ma) and underwent an extraordinary
ecological radiation after their arrival, thus making this group of great
interest for biogeographic and evolutionary studies. The aim of this article was to
provide a working hypothesis regarding the biogeographical history and ecological
diversification of one of its conspicuous families, the Octodontidae. We reconstruct
the evolutionary theater where their ecological diversification took place,
and potential events of dispersal, vicariance and extinctions. We analyzed the
historical biogeography of the Octodontidae across the eight ecoregions where
they occur, based on species phylogeny and divergence times. Four approaches
were used to reconstruct ancestral area: (1) Statistical Dispersal?Vicariance Snalysis
(S-DIVA); (2) Bayesian binary Markov chain Monte Carlo (MCMC) analysis
implemented in Reconstruct Ancestral State in Phylogenies (RASP); (3) Fitch
optimization method; and (d) weighted ancestral area analysis (WAAA). Parsimony
ancestral state reconstructions were implemented in order to explore the
evolutionary history of an ecological character, mode of life. We propose
the northern portion of the Monte desert ecoregion as the ancestral area in the
evolution of the Octodontidae, with subsequent dispersal and enlargement of the
family geographic range. The evolution of their ecological specialization (i.e.
modes of life) suggests an ambiguous ancestral condition (saxicolous, generalist
terrestrial, semifossorial) linked to species adaptation to arid environments, with
fossoriality appearing later in octodontid evolution. The evolution of the Octodontidae
is associated with contrasting environmental conditions (i.e. climate and
vegetation) produced by the Andean Uplift between eastern and western sides.