deciphering their diversity and evolutionary history

Smithsonian National Museum of Natural History

Asiloid Flies
deciphering their diversity and evolutionary history

Sample of Asiloid Flies

NSF REVSYS 2009-2012 Project Site

In July 2009, the U.S. National Science Foundation awarded a three-year project on Apioceridae, Asilidae, and Mydidae phylogeny, taxonomy, and biogeography to Torsten Dikow (PI, Field Museum of Natural History, Chicago, IL, USA) and David Yeates (Co-PI, CSIRO Entomology, Canberra, ACT, Australia). Project title: “Phylogeny, revisionary taxonomy & the fossil record of asiloid flies (Diptera: Apioceridae, Asilidae, Mydidae).” The project summary is provided below and additional information is provided by the following NSF site.

Project summary in scientific terms

Intellectual merit of proposed activity

This project deals with the species diversity, extant and historical distribution, and phylogenetic relationships of three taxa of true flies, i.e., Apioceridae, Asilidae, and Mydidae, of which several subordinate clades are restricted to the Southern Hemisphere. The project aims to postulate a total evidence phylogenetic hypothesis combining morphological and DNA-sequence data, review all fossil specimens available, and provide taxonomic revisions of selected, biogeographically interesting genera of the three families in order to: (1) review the morphology and biogeography of certain genera and describe yet unknown species; (2) examine the historical biogeography of the group, based on all available fossils and areas of extant endemism using specimen data of extant species particularly of the taxa restricted to the Southern Hemisphere; and (3) propose a chronology of divergences, based on cladistic placement of all available fossils and estimation of clade ages. The project will enhance our understanding of the evolutionary events that took place during the early diversification of this group in the Cretaceous. It will be informative for the Assembling the Tree of Life Diptera project because this speciose clade of Asiloidea, with approximately 7700 extant species, will be sampled much more comprehensively. The scenarios of historical biogeography will be augmented by estimations of the divergence times of clades, which will be based on the newly studied and cladistically placed fossil specimens, the proposed phylogenetic relationships, and estimation of clade ages with the molecular data.

Broader impacts resulting from proposed activity

The training component of the proposed project will have three different foci, i.e., (1) training of two undergraduate students during an extended internship in identifying, describing, and illustrating species as part of taxonomic revisions and publishing the results in printed and online media, (2) training of two undergraduate summer students in molecular laboratory techniques as well as phylogenetic analysis of the obtained DNA sequences combined with morphological data, and (3) collaborating with and supporting the training of a Ph.D. student at the Universidade de São Paulo, Brazil, who will study the taxonomy and phylogeny of the Mydinae. The dissemination of scientific knowledge to all parts of the world is of immense importance. The taxonomic revisions dealt with in the proposed project, including species descriptions and dichotomous identification keys, will be published in traditional paper format in scientific journals as well as on the world wide web as integrative biodiversity databases with the help of the Linnaeus II software package. Interactive, easy-to-use matrix-based identification keys to the revised species and all higher level taxa will be published online with the help of the Lucid 3.4 software. Species pages of the newly revised species will be submitted to the Encyclopedia of Life, which will shortly evolve into the primary online hub for information on species all over the world. Information for each species will be made available so that school children, the general public, informed amateur entomologist, and professional dipterists can use it (see Detail slider on EOL species pages). A meeting on Asiloidea flies, including collaborators from this project as well as previously NSF-funded projects on Asiloidea, will be organised and held at the Biodiversity Synthesis Center in order to combine efforts to provide data on this megadiverse Diptera group to the Encyclopedia of Life. The importance of DNA in collections-based research at a natural history museum will be explained to school children and the general public through the interactive DNA Discovery Center, which is part of the Pritzker Laboratory for Molecular Systematics & Evolution at the Field Museum.

Project summary for general public

The study of biodiversity has immense scientific and social value, especially today as it is under serious threat. This project deals with the species diversity, biogeography, and evolutionary relationships of three families of true flies (Diptera): flower-loving flies (Apioceridae), robber flies (Asilidae), and mydas flies (Mydidae). The focus of this project are those species which are restricted to the arid environments in the southern Hemisphere and western North America, areas that are part of global biodiversity hotspots. Particularly flower-loving flies and mydas flies are rare and have not received the scientific attention they deserve. Field work in Australia, Chile, South Africa, the USA and other countries will allow the investigators to collect and preserve specimens for morphological and molecular research techniques that will be used to describe newly discovered species as well as provide hypotheses of the evolutionary relationships and biogeography and propose a timeline of evolutionary divergence. Previous hypotheses of relationships and biogeography will be tested by incorporating additional recent species and newly studied fossil species.

This project will help to understand the diversification of these flies during the Cretaceous period coinciding with the diversification of flowering plants. In addition to scientific journals, the investigators will publish their results online on the project web-site and in the Encyclopedia of Life, both of which are openly accessible. Tools will be developed and made available online to allow future scientists to identify species of all three families. Four undergraduate students will be trained in the taxonomy of true flies and molecular laboratory techniques. A graduate student from Brazil will spend part of her dissertation studies at the Field Museum of Natural History working on taxonomic and phylogenetic projects on an entirely New World group of mydas flies.