Filogenia e biogeografia das espécies de actinote hübner, 1819 (Nymphalidae : Heliconinae) / Phylogeny and biogeography of species of actinote hübner, 1819 (Nymphalidae : Heliconinae)

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

13/02/2012

RESUMO

Many aspects and details of the origin, evolution and biogeographical patterns of butterflies are not yet fully comprehended. The phylogenetic relationships among most butterfly groups remained unknown until recently. Phylogenetic studies have been based mainly on morphological characters of adults, although characters of immature stages had increased in use and importance nowadays, specially due to their capacity of been informative where adult characters are not enough. There are few studies that use these characters either to phylogeny or classification of the butterflies. Besides the lack of information about the common ancestry of butterflies, there are also gaps to be filled about the biogeographical patterns, primarily related to the historical biogeography. In the neotropics, the planet s most biodiverse region, the study of origin and biogeography of most groups of organisms, including butterflies, is a subject of great interest. This because most of these groups are poorly understood concerning their evolutionary histories and shed light on some of these histories would lead us toward the comprehension of this huge Neotropical diversity. Despite being one relatively well known group, the genus Actinote (Nymphalidae: Heliconiinae) still lacks studies in phylogeny to solve the internal relationships of this group. It also lacks studies that seek to understand the distributional patterns of the group in the Neotropical region and which factors were responsible for the high diversity of Actinote in the southeast region of South America. In the present study we carried out three phylogenetic analyses based on morphology, with 34, 31 and 29 táxons respectively. In all analyses the majority of the clades were supported by homoplasies, although some groups of few species were maintained apparently the same in all the analyses supported by synapomorphies. Despite the fact that many discussions point out to a great importance in the use of immature characters to help solving the common ancestry relationships of butterflies, in the present work these characters were not very informative to elucidate the relations of this group, although they have a great taxonomic value, being helpful in the identification of the majority of species. This is probably due to a great intraspecific variation and a lower congruency with the adults characters which would make it harder to use these characters to try and solve the evolutionary relationships of this particular group. Some authors claim that this difficulty could be a result of a rapid diversification during the evolutionary history of these species, restricting the morphological differentiation. The biogeographical analysis was carried out with the program Reconstructing Ancestral States in Phylogeny (RASP). According to the optimal biogeographical hypothesis, the distribution pattern observed could be explained by 41 dispersal, six vicariant and three extinction events. The analysis pointed out to a spread distributed ancestor of Altinote and Actinote, occupying the Andes and the Serra do Mar, in southeast Brazil. A vicariant event had isolated the ancestor lineage of Altinote in the Andes and the ancestor lineage of Actinote in the southeast of South America. The vicariant events could be related to climatic changes, what makes sense to this particular group, which is typical of cold high altitude habitats. According to this hypothesis, during the glacial periods the species of high altitude habitats could disperse and reach low altitude habitats. When the temperatures got higher in the interglacial periods these species were trapped in high altitude places, of lower temperature, and became isolated. If this isolation period lasted long enough, the species could pass through speciation events, turning into new species.

ASSUNTO(S)

lepidoptera borboleta - filogenia biogeografia altitude lepidoptera butterfly biogeography altitude

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