Gustavo Hormiga - US grants

9712353 HORMIGA Spiders are numerous, widespread and have a direct impact on human affairs. About 30 species inflict medically important bites; more generally, spider venoms are used in medical and pharmaceutical research. Spider silk has extraordinary physical properties; silks and their constituents are foci of biotechnological research with possible commercial applications. Spiders also regulate insect populations in natural and agricultural environments. Nevertheless spider diversity and biology are inadequately understood. About 36,000 species are known to science, less than half of the number thought to be present on Earth. Faunas in tropical and Southern Hemisphere temperate areas are most poorly known. Even for the described species, accurate identification manuals, keys, monographs and phylogenetic analyses are, for the most part, lacking. In this PEET proposal, Gustavo Hormiga, John Coddington and colleagues will improve the state of spider taxonomy by conducting monographic research within three subfamilies (Linyphiidae; Theridiidae; Tetragnathidae) of araneoid (Araneae) spiders. The monographic research will make use of museum and field-collected specimens to describe new species, produce keys to species, reconstruct phylogenetic relationships among the species, and develop a computerized information system linking text, data, and image files and available via the World Wide Web and CD-ROM. The research will train three new taxonomists in modern methods, developed and applied to spiders, during the course of the project.

Abstract Hormiga

A variable pressure scanning
electron microscope (SEM), a critical point dryer and a sputter coater will be used for
research in the systematic biology of various groups of organisms. This SEM
will be used to collect morphological data of a wide variety of living and
extinct organisms. This equipment, together with existing dissecting and
light microscopes, a CCD digital camera for microscopy, scanners and
computer workstations will be used to establish a core microscopy and image
analysis facility in the Department of Biological Sciences at George
Washington University. Access to SEM is essential to accomplish the goals
of six research groups (four of them with active projects currently funded
by NSF) in the departments of Biological Sciences and Anthropology at The
George Washington University. At present at least seven faculty, two
postdocs, and 17 graduate students will be using this instrument.
The following research projects will use the SEM
facility described in the proposal: Systematics of araneoid spiders; Evolutionary history of flowering plants; SEM analysis of skeletal tissue growth;
Systematics of Ciliated Protista; Anatomy and
phylogeny of dinosaurs and other mesozoic reptiles; and
SEM analysis of spermatozoa, spermatozeugmata, and secondary sex organs of
inseminating ostariophysan fishes.
Over the next three years these researchers and
their collaborators and students will have to take an estimated 21,000 SEM
micrographs in the course of the research projects described in this
proposal.

Abstract

Assembling the Tree of Life: Phylogeny of Spiders

Ward C. Wheeler, Jonathon A. Coddington, Gustavo Hormiga, Lorenzo Prendini, and Petra Sierewald

American Museum of natural History

A grant has been awarded to Dr. Ward Wheeler of the American Museum of Natural History and his colleagues Dr. Lorenzo Prendini (AMNH), Dr. Jonathan Coddington (National Museum of Natural History, Smithsonian Institution), Dr. Gustavo Hormiga (George Washington University) and Dr. Petra Sierwald (Field Museum of Natural History) to examine the evolutionary history and biodiversity of spiders. Spiders are among the oldest and most diverse groups of terrestrial organisms on our planet, with fossils dating back to the Devonian (c. 380 million years ago) and a current diversity of over 37,500 described species placed in 3,471 genera and 109 families. Spiders stand out because of their ecological importance as the dominant predators of insects. It is no exaggeration to say that without spiders, insect pest populations would soar and humans would be greatly affected. Furthermore, spiders are already model organisms in biochemical (silk proteins and venom), behavioral (especially sexual and web-building behaviors) and ecological (foraging, predator-prey systems, integrated pest management) research. Accordingly, understanding their evolutionary history is a critical component in the NSF's Assembling the Tree of Life program.
The aim of this Tree of Life proposal to produce a robust phylogeny of all the deepest branches within the spiders, by combining a massive amount of newly generated comparative genomic data with a substantial set of new and re-assessed data on morphology and behavior. The PIs will use high-throughput DNA sequencing to examine at least 50 "loci" for representatives of at least 500 genera of spiders and their closest relatives (the whipscorpions and allies). The computational challenges posed by the resulting large data matrices will be analyzed using new computer software, designed in large part by members of the group and using massively parallel processing to achieve supercomputing capability. These organisms included in the study will purposefully include all the previously most-favored study organisms of ethologists, ecologists, physiologists, and developmental and molecular biologists, thus integrating and contextualizing their research.

The award supports the purchase of an automated, eight-capillary sequencer, a PCR thermal cycler, and associated equipment needed for DNA sequence determination and subsequent analysis. The instruments will be used create a sequencing facility for use by faculty and students in the University's Department of Biological Sciences. Anticipated uses include a diverse array of research projects including systematics of spiders, plants and vertebrates; evolution of the immune system; plant signaling networks; and plant phylogeny. Sequence data are of central importance for analyzing gene structure and expression, and for predicting, characterizing and manipulating protein function in cellular and molecular biology. Sequence data are also important in systematic biology where DNA data are used with morphological data to understand the phylogenetic relationships among organisms. The equipment will be available for use in both research and training. In addition to faculty and postgraduate researchers, undergraduate students doing independent research or laboratory exercises will be able to use the instruments.

In a renewal of a highly successful program of taxonomic research and training in the PEET activity, Partnerships for Enhancing Expertise in Taxonomy, Prof Gustavo Hormiga at George Washington University and colleagues at Harvard University, the California Academy of Sciences, and the Smithsonian seek to train additional systematic biologists (two likely Ph.D. students and one postdoctoral scholar) in monographic and revisionary study of a megadiverse group, spiders. The trainees, working in close collaboration with the PIs and several expert collaborators, will study and describe spider species in the orb weaving families Tetragnathidae and Mysmenidae. The main goal is to train three taxonomic experts in several critically understudied groups of mostly tropical spiders. These trainees will receive state of the art education in systematic methods and will interact with a diversity of project collaborators and academic and research institutions. Their training will allow them in the future to carry out systematic research on any taxonomic group of spiders. The phylogenetic component of these projects will use character evidence from morphology, behavior and DNA sequences. The taxonomic aspects of this research will make extensive use of computerization and web-based dissemination. The monographs and systematic data resulting from this research will be published in peer reviewed journals.
In addition, the project web site (www.gwu.edu/~spiders/) will serve as an outlet to advertise research results and to disseminate these, including: Interactive identification keys, Digital Image Banks (of taxonomic images of the world genera of Tetragnathidae and Mysmenidae to assist with identification), Database of images of web architecture (with images hyperlinked to a file with the specimen voucher data), and Specimen
databases of geo-referenced material for the monographed taxa.

Researchers from three U.S. museums and two U.S. universities, plus a
worldwide group of over 20 colleagues, will collaborate to conduct a global
survey and inventory of the dwarf hunting spiders. These animals are very
poorly known; preliminary data indicate that the 459 currently described
species represent only about 20% of the actual diversity of the group. The
team will assemble and sort the specimens available in collections and
acquire new material through 12 expeditions that will concentrate on
securing better samples of forest floor and canopy-dwelling species. Team
members will build Internet-accessible databases of the species, all specimen locality
data, and images; a new application will allow team members to enter descriptive
data into a multi-user database, in a highly structured format that will
allow direct use of that information in formal descriptions for
publication, on species web pages, in phylogenetic analyses, and in
interactive keys. Automated identification systems, using artificial
neural networks, will be developed, and the accuracy of those systems will
be compared with that achieved by workers, ranging from total beginners to
knowledgeable specialists, using interactive keys to the same species.

Other impacts of the project include training several high
school, undergraduate, graduate, and postdoctoral students (with emphasis
on recruiting members of groups currently underrepresented in the science
workforce). Project outreach plans include a major traveling museum
exhibition designed to focus public attention on the importance and
excitement of biodiversity discovery and preservation. Extensive
public-aimed web materials will be developed that will be useful for
pre-college level teaching.

Arachnids comprise one of the most diverse groups of animals, with numerous representatives in all terrestrial ecosystems. Aside from Acari (mites and ticks), whose total estimated diversity might reach up to one million species, the orders Araneae (spiders) and Opiliones (harvestmen or daddy longlegs) are the most diverse arachnid lineages. The main goal of this project is to carry out taxonomic revisions (monographs) of several lineages across selected Neotropical groups in two arachnid orders (Araneae [spiders] and Opiliones [daddy long legs]). The groups that we have targeted in this proposal are mainly leaf litter inhabitants (except for mimetids), grossly undersampled and understudied, that lack modern revisionary work and include many undescribed taxa at the species level and above, and thus provide excellent research and training opportunities in modern monography and systematics. The largely overlapping Neotropical distribution of our study groups allows us to effectively collect these arachnids in joint field expeditions. Some of these study taxa also pose similar biogeographic and evolutionary questions that can be addressed with common methodology and expertise.

To carry out our research and training goals the PIs have assembled a team of scientists with diverse backgrounds in systematics and arachnology and a demonstrated history of successful collaborative research efforts. Combining research efforts to tackle these taxonomic problems provides the empirical basis for our multi-ordinal and multidisciplinary approach for training doctoral students in the broadest possible way. Lab rotations and collaboration among the multiple investigators participating in the projects, in addition to the joint field expeditions, also contribute to this synergism. Research results will be disseminated in high impact portals such as Encyclopedia of Life and Tree of Life. Online interactive identification tools will also be produced.

This project will chronicle the evolution and diversification of the orb-weaving spiders to resolve a long-standing problem in animal evolution, that is, the origin and genealogical relationships of the main groups of orb-weavers. Ubiquitous, diverse, and exclusively predatory, spiders are one the most diverse and fascinating animal groups and the dominant arthropod predators in most terrestrial ecosystems. Orb-weavers are remarkable not only because of the high number of species described so far, but also because of the extraordinary architectural diversity of their foraging webs, ranging from highly geometric snare designs, often regarded as a pinnacle of animal engineering, to sheet and irregular cob webs. Understanding web evolution and diversification requires an empirically robust hypothesis about the underlying genealogical patterns?the spider tree of life. Traditional anatomical and genetic methods have not yet produced a compelling answer to this problem, and thus our understanding of the evolution of this group is far from satisfactory. The researchers of this project will use new methods to gather genetic data to answer this long-standing question. The results of this research will be of interest to many biologists working on any comparative aspects of orb-weavers because it will provide the genomic resources and the fundamental comparative basis for studies on a broad diversity of topics (silk biology, sexual selection, venom evolution, etc.). This project will serve as a training platform for postdoctoral, graduate and undergraduate researchers. In addition, the project will produce a public exhibit at the Harvard Museum of Natural History that will explore the evolution and biology of orb-weaving spiders.

A team of three investigators, experts in arachnid systematics and with a long and productive history of research collaboration, will generate novel data through the sequencing of 120 transcriptomes and target capture approaches using modern DNA sequencing techniques for phylogenetic inference for a taxonomic sample of orbicularians that would include representatives of all 21 known families of orb-weavers and a diverse array of outgroups. These genomic data will be used to infer the family-level phylogenetic relationships of orb-weaving spiders using a diversity of analytical techniques. The PIs will also analyze a morphological matrix of 85 selected orbicularians largely based on extensive data already at hand. This project will use the results of the phylogenetic analyses to carry out comparative analyses of orb-weaver diversification and of web architecture evolution.