Geographic limits and causal agents of Diptera endemism in the Atlantic Forest

Abstract

Knowledge on biodiversity does not correspond merely to a list of names. Biological diversity is heterogeneously distributed in space. Even though attention given to biodiversity has grown in the last decades, quite few is actually known about the geographic patterns of distribution of species and the causes of these patterns. In other words, it is still not possible to map the distribution of Brazilian species of most groups - not even in the most well studied areas. Neither is it possible to determine the sequence of events in the history of the continent that have determined these patterns of distribution. This deficiency in knowledge has implications for the conservation policy and for the understanding of basic evolutionary processes. Conservation decisions greatly depend on the precise knowledge of the geographic distribution of species. The understanding of the evolution rate deeply depends of a correct association between geographic limits of species and the age of the events causing these cladogenetic process. In the literature, biological and biogeographic theories strongly clash on this respect. This project intends to use biological material collected with standardized methods along the Atlantic Forest, with emphasis on the state of São Paulo, to delimit areas of endemism of Diptera groups and to apply phylogenetic and biogeographic methods of analysis to study congruence among these patterns. Biogeographic patterns congruent with the geological history of South America point to groups associated to the geological origin of the continent in the Gondwanaland, in a way that the diversity of these groups would have slowly originated along the last 80,000,000 years. Patterns that disagree from the general biogeographical pattern and of South America geological history probably originated in the region due to dispersion specially from the Nearctic Region. The study of a rich assemblage of Diptera specimens along the project allows the construction of a home page with photographs, identification keys, catalogs of Neotropical species, and information on biology and distribution maps. This is a efficient mechanism of making technical information available for a public with different levels of interest on Diptera or on conservation. (AU)