Diversificação de roedores do gênero Phyllomys (Mammalia: Rodentia: Echimyidae) na Mata Atlântica brasileira

• Ano de defesa: 2010
• Autor(a) principal: Loss, Ana Carolina
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Biologia Animal; UFES; Programa de Pós-Graduação em Ciências Biológicas
• Palavras-chave em Português: Callistomys; Euryzygomatomys; Biogeografia; Filogenia; Rato-de-espinho; Zoologia; 57
• Link de acesso: http://repositorio.ufes.br/handle/10/3816

The Neotropical rodents of the Echimyidae family are the most diverse among the Caviomorpha clade. Little is known about the geographic range, natural history and evolution of several Echimyidae members, despite its high diversity. The taxonomic history of the family is confusing and some groups are rare in scientific collections, resulting in less conclusive inferences about evolutionary and biological traits, which are based on a few individuals. Molecular phylogenies do not support the taxonomic classification based on morphological traits, highlighting the complexity of the evolutionary history of this group. Five Echimyidae genera occur within the Atlantic Forest range: the bamboo-rat, Kannabateomys; the arboreal Phyllomys and Callistomys; the terrestrial Trinomys; and the semi-fossorial Euryzygomatomys. In the present study I used DNA sequences to investigate the phylogeny and evolutionary history of three echimyids from the Atlantic Forest at three different taxonomic levels: family, genus, and species. The first chapter investigates the phylogenetic position of Callistomys within Echimyidae using sequences of one mitochondrial (CytB) and three nuclear (GHR, RAG1 and vWF) markers. The results show that Callistomys forms a clade with the semi-aquatic coypu (Myocastor) from the grasslands in the southern South America and terrestrial spiny rats (Proechimys) from the Amazon forest. This clade is sister to Thrichomys, a terrestrial rat from the dry lands of central South America. These clades are unexpected, given the contrasting morphology, ecology, and geographic ranges of its members. The resulting echimyid phylogeny indicates that Callistomys is not closely related to the other arboreal echimyids, and suggest that arboreal habits evolved more than once in this family. The second chapter investigates aspects of the phylogeny, evolution and species limits in the genus Phyllomys using two mitochondrial (CytB and COI) and three nuclear (GHR, RAG1 and vWF) markers. Three main species groups were identified: one with a longitudinal distribution through the central portion of the Atlantic Forest (P. pattoni (P. mantiqueirensis, Phyllomys sp. 4)); one distributed along the northern portion of the Atlantic Forest (Phyllomys sp. 2 (P. blainvilii (P. brasiliensis, P. lamarum))) and another along the southern portion (Phyllomys sp. 3 ((Phyllomys sp. 1, P. lundi), (Phyllomys sp. 5 (P. dasythrix (P. nigrispinus (P. sulinus, Phyllomys sp. 6)))))). Two independent evolutionary linages were identified, probably representing new species, raising the potential number of Phyllomys species from 17 to 19. These phylogenies, together with geographic distribution data, suggest that the diversification and distribution of Phyllomys species were affected by the concomitant action of different factors, such as neotectonics, altitudinal and latitudinal gradients, and climate change acting since the Miocene, underlining the first diversifications within Phyllomys until more recent speciation events, during the Pleistocene. The third chapter explores the genetic variation, geographic distribution and taxonomic status of the species Euryzygomatomys spinosus using two mitochondrial markers (CytB and D-loop). The results show that E. spinosus is distributed along the Atlantic Forest and surrounding areas, south of the Rio Doce in Brazil, Paraguay, and Argentina, including a confirmed occurrence in the Cerrado. This species occupies very distinct habitats and may be consider a generalist. The populations are genetically structured along its distribution and the genetic data corroborate the current taxonomy, which considers only one species in the genus, E. spinous.