Relações filogenéticas de rodentia: uma abordagem comportamental / A behavioral approach to the phylogeny of Rodentia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The phylogenetical relationships within Rodentia are complex, and the position of Hystricognathi differs when estimated through different kinds of data (morphology or DNA). This paper focuses on a still different kind of data: we estimate the phylogeny of the group through behavioral characters. We obtained probabilistic grooming sequences with the program EthoSeq, in a group of 12 rodent species. The ingroup consisted of five Sciurognathi [Calomys callosus (Cc), Mesocricetus auratus (Ma), Rattus norvegicus (Rn), Mus musculus (Mm), e Meriones unguiculatus (Mu)] and seven Hystricognathi [Cavia aperea (Ca), C. porcellus (Cp), C. intermedia (Ci), Coendou prehensilis (Cop), Trinomys yonenagae (Ty), Thrichomys pachyurus (Tp) e Thrichomys laurentius (Tl), this last species represented by two different populations, one from Bahia and another from Piauí state. The outgroup consisted of two species: Felis silvestris f. catus and Oryctolagus cuniculus. The analysis shows that the use of different levels of behavioral complexity (isolated behavioral units, sequences of two units dyads, and longer sequences routines) is necessary for the resolution of the relationships of the taxa studied. The program TNT was used for the cladistic analysis of a matrix with 23 continuous characters (frequency of grooming units) and 7152 discrete characters (grooming sequences). We obtained one single most parsimonious tree: (Fc, (Oc, (Cop, (Ci, (Ty, (((Ca, Cp), ((Tl-BA, (Tp, Tl-PI)), ((Mm, Rn), (Mu, (Cc, Ma)))))))))). This result shows that behavioral characters are adequate to solve the internal relationships even of complex groups such as Rodentia. There is phylogenetic signal in frequency of grooming units. Although Rodents result monophyletic in our analysis, we could not solve the relationships within Hystricognathi. The two populations of Thrichomys laurentius appear as 10 distinct species. We suggest that other behavioral characters should be combined with other, morphological and/or molecular databases, in order to clarify the relationships within Rodentia, specially within the South America histricognaths.

ASSUNTO(S)

animal grooming behavior comportamento de limpeza animal phylogeny etologia animal rodents filogenia animal ethology roedores

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