Patrick S. Herendeen - US grants

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.

0206512
Herendeen and Clark
The genus Alloplectus, a common shrub from the northwestern Andes, has flowers that may be viewed as an upside down version of those of the Florists' Gloxinia. Alloplectus and the Florists' Gloxinia both belong to the same group, but the flowers are resupinate (inverted) in some species of Alloplectus. This project will look at the pattern of diversification in Alloplectus and related members of the family Gesneriaceae and the evolution of flower resupination in this group. The Neotropical members of Gesneriaceae are problematic because morphological details are poorly documented, closely related taxa exhibit a wide range of flower forms, pollinators are poorly known, and molecular phylogenies have insufficient species sampling to clarify the wide range of morphological variation. One of the least understood groups of Neotropical gesneriads is the genus Alloplectus. This project will generate phylogenetic hypotheses to test competing theories of gesneriad evolution, to resolve phylogenetic relationships within the tribe Episcieae, and to complete a taxonomic revision of the genus. Field expeditions will be carried out in Bolivia and Panama to study the plants and their pollinators and collect material for study in the laboratory and herbarium. Visits to European herbaria will be conducted to study historical and recent plant collections. Molecular sequence data will be collected for the nuclear ITS region and the chloroplast trnL intron and spacer. Morphological characters will be studied and scored for phylogenetic analyses.
Although tropical ecosystems are attracting increasing attention from biologists and conservationists interested in understanding and managing the earth's biological resources, there is much that is not understood about the diversity of plants and other organisms that make up these ecosystems. For example, there are at least five species of Alloplectus that are new to science and many members of this group are geographically restricted and live in forests that are threatened by logging and agricultural conversion. Results from this project will provide a robust phylogenetic hypothesis and data that may be used to address questions about plant diversity and conservation, morphological evolution, and pollination biology in this poorly known group of tropical plants.

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.

The Leguminosae (or Fabaceae - the legume or bean family) is the third largest family of flowering plants, and the second most important family economically. Legumes range from giant rain forest trees to tiny herbaceous annuals of desert habitats. Of the three traditionally recognized subfamilies, Caesalpinioideae, Mimosoideae, and Papilionoideae, the Caesalpinioideae is the most poorly known because it is largely confined to tropical habitats. As a consequence, evolutionary relationships among caesalpinioid legumes are poorly known and the recognition of particular genera is often in dispute. Previous work by Dr. Herendeen and his colleagues in Canada and England has developed a general phylogenetic framework for Caesalpinioideae, which will be used to further research on morphology, taxonomy, and phylogeny. Current morphological and molecular data show that several caesalpinioid lineages have more basal positions than either the Mimosoideae or Papilionoideae. Thus a classification system for the family based on evolutionary relationships would not recognize the caesalpinioids as a single natural unit but as several early-branching lineages. How many distinct lineages of caesalpinioid legumes are there, at what level should they be recognized relative to mimosoids and papilionoids, what are the relationships among caesalpinioid genera, and what can we discern about patterns of morphological evolution? These questions form the core of the study.
The primary goal of this research is to produce a classification that includes all ca. 160 genera of caesalpinioid legumes based on analyses of data from morphology and DNA sequence data. To achieve this, field work will be conducted in Madagascar, South America, and SE Asia to obtain material of as many of the missing genera as possible. The investigators will also study collections in herbaria and prepare anatomical samples to score morphological characters for all species included in the molecular data set. They will use the phylogenetic results to produce a revised classification and identification key to subfamilies, tribes, and genera for all caesalpinioid legumes. With a robust phylogeny and a specimen-based morphological data set, they will be able to explore the implications of the phylogeny with respect to patterns of morphological evolution. In addition, data on a diverse array of fossil legumes will be integrated with the results. The fossils may be used in documenting minimum ages of clades and as historical data points for biogeographic studies. In addition, molecular clock techniques will be used to estimate ages of clades. The data generated in this study will make the Leguminosae an ideal group in which to experiment with new methods in estimating ages of clades and assessing rates of taxonomic diversification and molecular evolution.

The legume family (650 genera/~18,000 species) is the third largest family of flowering plants and the second most economically important family. The subfamily Caesalpinioideae has received relatively little attention and recent morphological and molecular evidence suggests this subfamily may not be a natural group. Part of the reason for the uncertain status and relationships of the members of the Caesalpinioideae is that many of the genera and their species are poorly known and rarely collected. The study of plant taxonomy and phylogeny is inherently dependent on field work, many times in remote areas, which is the case for caesalpinioid legumes in general, and in this study in particular. The research outlined in this proposal will provide monographic revisions and species-level phylogenetic hypotheses for a group of poorly known caesalpinioid legume genera that are endemic to the Guiana Shield area of South America (Venezuela, Suriname, French Guiana, and Guyana). Funding from the NSF DDIG program will allow Ms. Redden to travel to museums in Venezuela and Europe to examine herbarium material that is needed for this study, and to conduct field work in southern Venezuela to collect plant specimens, dried leaf samples, and pickled flowers for study. A total of five weeks will be spent in the Sierra de la Neblina area of Venezuela. While in Venezuela, Ms. Redden will also visit five herbaria to gather information on plant characteristics and distribution for the monographic and phylogenetic aspects of this study. The primary objectives Ms. Reddens dissertation are to provide a systematic revision of five key genera of the group (Dicymbe, Paloue, Paloveopsis, Heterostemon and Elizabetha) and to study morphological evolution, especially floral morphology, in this group.

Working directly with Venezuelan scientists, students, and local communities is an essential part of this study. These activities will enhance collaboration with Venezuelan botanists, including students, and will contribute to broader studies of relationships within Caesalpinioideae. While conducting research in the Venezuelan herbaria Ms. Redden will examine and photograph specimens, verify identifications, and identify unknown material wherever possible. In addition to locating important specimens for her research, Ms. Reddens herbarium work in Venezuela will help to improve their collections. We have been working with Dr. Basil Sterigos with the Universidad Nacional Experimental de los Llanos Occidentales Ezequil Zamora(UNELLEZ) in planning the field work. Dr. Stergios and his student will accompany Ms. Redden on the field expedition. This expedition will not only contribute vital information to the dissertation project, it will also document biological diversity in Venezuela. Voucher specimens will be made for the Smithsonian Institution (US), Herbario Universitario BioCentro-UNELLEZ (PORT), and Herbario Nacional de Venezuela (VEN). In addition to the plant collections, all other information will also be shared with UNELLEZ. Photographs, GPS coordinates, field notebooks, and other data also will be copied and left with UNELLEZ.