2002 Grad Symposium

Ecology and Evolutionary Biology
12th Annual Graduate Student Symposium
Saturday, March 2nd, 2002

The symposium will be held at South Campus Lewis B. Rome Hall (Building D) in the ballroom on the second level. Parking is available next to the building. Southbound on 195, pass Mirror Lake and take the second right (Bolton Rd.) - it is opposite Store 24. Park in S-lot which is on either side of the road. The building is on the north side of the parking lot. All doors of the building will be open. Go to the second (top) floor.

2002 Symposium Committee:

Florian Reyda
Gregor Yanega
Patrick Owen

Schedule: Click on the author's name to view abstract

8:30	Breakfast
9:00	Kent Wells	Opening remarks
9:15	Norman Wickett	Systematics and molecular evolution of the parasitic liverwort genus Cryptothallus
9:30	Florian Reyda	Tapeworms of tapeworms of potamotrygonid stingrays of southeastern Peru
9:45	Brigid O'Donnell	The development and evolution of gill morphology in mayflies
10:00	Michael Moody	Foiled again: hybridity in invasive hydrophyte populations
10:15	Break
10:30	Hilary McManus	A new stem with unusual anatomy from the Triassic of Antarctica
10:45	Michael McAloon	Elephants, tapeworms and mites: the life cycle of Anoplocephala manubriata revealed
11:00	Patrick Owen	The evolution of aggressive calls in chorus frogs, genus Pseudacris
11:15	Christopher Martine	The taxonomy and evolutionary history of the woody plant genus Maclura
11:30	Jose Pereira	Using geographic information systems to document fish habitat use
11:45	Kealoha Freidenburg	The effect of environmental heterogeneity on oviposition site choice and larval performance of the wood frog (Rana sylvatica)
12:00	Lunch
1:00	Stacey Leicht	Invasive species assessment in the Quinebaug Highlands
1:15	Lori LaPlante	Estimating the annual fecundity of tautog (Tautoga onitis) in Long Island Sound, CT
1:30	Gale Ridge-O'Connor	Heteroptera thoracic endoskeleton
1:45	Nicola Plowes	Small warriors: the costs of waging war
2:00	Uzay Sezen	Seed-mediated gene flow and parentage in a regenerating second-growth neotropical forest
2:15	David Lubertazzi	Longleaf pine, habitat conservation and the imported fire ant
2:30	Break
2:45	Robynn Shannon	Phenology and life history of the brown algae Petalonia fascia and Scytosiphon lomentaria in New Hampshire
3:00	Nancy LaFleur	Participation of invasives in an avian-mediated seed dispersal system
3:15	Derek Sikes	Bibliographic taxonomy (a.k.a. The Valley of the Shadow of Death): Lessons from the other side
3:30	Patrick Herron	Novel techniques for the measurement of sugar exudation patterns in the rhizosphere
3:45	Kitty Englemann	Plastic response to fine versus coarse grained water stress in Arabidopsis
4:00	Andrew Townesmith	Linguistic artifacts: etymological patterns in the Native American origins of English terms for New World plants and animals
4:15	Robert Dunn	What the queen knows: the use of social insects as medicine

Abstracts:

Dunn, Robert and Monica Sanchez
What the queen knows: the use of social insects as medicine
Social Insects are used by indigenous groups throughout the tropics as medicine. Enthographically this use has often been ignored or described only generally (e.g. "they used the little black ant"). Nonetheless, analysis of Amazonian ethnographies shows that social insects are used as medicine more than other insects. Case studies suggest that this may be due both to cultural and biological factors. From a cultural standpoint, the metaphorical similarity of insect and human societies, leads to a vision of social insects as powerful and sometimes curative. Biologically, as social systems,social insects are susceptible to bacteria and fungi and have evolved methods to combat those pathogens, which humans co-opt. Ethnographers, biologists and medical anthropologists are all likely to gain by incorporating social insects into studies of indigenous pharmacopia.

Englemann, Kitty
Plastic response to fine versus coarse grained water stress in Arabidopsis
Organisms routinely experience both coarse grained and fine grained environmental variation. However, most studies of plastisticy only look at course grained variation. Our study looked at the response of 17 ecotypes and two mutant strains of Arabidopsis thaliana in response to fine and coarse grained water stress. We found that the response to the two types of variation differed by the number of traits affected, the intensity of the response, the direction of the response and the sensitivity to genetic background. These results suggest that the temporal scale of environmental variation is an important determinant in adaptive evolutionary mechanisms.

Freidenburg, Kealoha
The effect of environmental heterogeneity on oviposition site choice and larval performance of the wood frog (Rana sylvatica)
Oviposition site choice in amphibians has often been linked to avoidance of predators or competitors. However, fine-scale variation in abiotic variables could affect the performance of embryos and hatchlings, and adults may use these variables as cues. In this study, I investigated the effect of oviposition site choice on both embryos and hatchlings of the wood frog, Rana sylvatica. For the first experiment, I selected two sites for the embryos; the original oviposition site and an alternate site. Equal numbers of egg masses were placed in each site and allowed to complete development. Mortality and time to hatching were recorded as were measures of abiotic variation. This experiment was repeated in four ponds. For the second experiment, I placed these hatchlings in four patches within each pond and evaluated performance over two weeks. In the embryo experiment, hatchlings placed in alternate sites generally hatched later and smaller. In the patch experiment, hatchling growth and development varied among patches, but the size of this effect varied among ponds. The effect of the embryonic environment was retained after two weeks in some ponds and lost in others. The results of this study demonstrate that within-pond environmental heterogeneity can affect the performance of both embryos and early larval stages, and that adults may choose oviposition site choices based on cues related to light and thermal gradients.

Herron, Patrick
Novel techniques for the measurement of sugar exudation patterns in the rhizosphere
We are developing a technique to sense the release of sugars from roots in an intact soil matrix with all native microbial components present. The ability to track the release of carbon from roots will contribute to an understanding of how plants interact with soil microorganisms to mediate nutrient availability in the rhizosphere. We are using GFP expressing biosensors (Sinorhizobium meliloti) encapsulated in Sodium alginate/Polyethylene glycol beads to sense the release of galactoside sugars from roots. This technique allows non- destructive, spatially explicit measurements of the rhizosphere to be performed in non- sterile conditions. Previous attempts to measure sugar exudation in the rhizosphere have required the plant to be grown in sterile media or alternative substrates and yielded little spatial information. Biosensing beads have been applied on Avena barbatum in soil microcosms with promising results.

LaFleur, Nancy
Participation of invasives in an avian-mediated seed dispersal system
During the past two years I have examined the participation of an invasive frugivore, the European Starling (Sturnus vulgaris) and four species of fruit-producing invasive plants in an established avian-mediated seed dispersal system. I will present data on seed rain, passage rates and fruit choice gathered using field work and captive starlings.

LaPlante, Lori
Estimating the annual fecundity of tautog (Tautoga onitis) in Long Island Sound, CT
Tautog (Tautoga onitis) are long-lived fish that have been steadily declining in the western Atlantic; exploitation during their spawning season by commercial and sportfishermen have been proposed as a likely cause. Estimates of seasonal fecundity for this multiple spawner would help to assess impacts and develop recovery plans for the species. Understanding the influence of individual and intraseasonal variations can provide greater precision in determining a female's annual reproductive output. We conducted field and captive studies that investigated the influence of both individual and temporal effects on annual fecundity of tautog. Larger females spawned more frequently and larger batches of eggs than smaller females, and all mature females had a peak spawning period mid-season. Results from this study yielded higher estimates of annual fecundity for an individual than estimates made using traditional methods.

Leicht, Stacey
Invasive species assessment in the Quinebaug Highlands
The Quinebaug Highlands Landscape Project Area is a new 172,000 acre focus area for the Nature Conservancy. In the summer of 2001, data were taken in 188 plots by the Nature Conservancy to assess presence and cover of selected invasive species in a 34,000 acre block of contiguous forest within the focal site. In order to determine what types of information could be obtained from these data, GIS was used to 1) map the distribution of invasive species across the array of sample plots. 2) characterize the abundance of a specific invasive, Japanese barberry (Berberis thunbergii DC), within the invaded plots, and 3) determine which areas of the study site were more susceptible to invasion than others. These preliminary determinations were made through the construction of "risk maps" which weighed a variety of different factors to determine susceptibility to invasion. Two risk maps were made; one for Japanese barberry the second for autumn olive (Elaeagnus umbellata Thunb.).

Lubertazzi, David
Longleaf pine, habitat conservation and the imported fire ant
Conserving habitats through preserving natural plant communities is touted as a way to preserve an areas’ resident species. Research investigating the ant community found in a longleaf pine (Pinus palustris) habitat illustrates a problem with this approach. The ground cover naturally found in pine flatwoods is a diverse plant community dominated by herbaceous species. This vegetation is maintained by low-intensity growing season fires. Prescribed burning is being used to increase herbaceous ground cover in remnant pine flatwoods, which in turn is thought to positively influence populations of most native species. My work shows a positive correlation between herbaceous ground cover and abundance of the imported fire ant (Solenopsis invicta). Increasing the amount of herbaceous ground cover is therefore likely to increase the abundance of Solenopsis invicta. This behaviorally aggressive ant can have adverse effects on populations of many organisms. This work shows that we need to be careful in assuming that conservation of natural plant communities will preserve viable populations of a diverse array of native biota.

Martine, Christopher
The taxonomy and evolutionary history of the woody plant genus Maclura
The plant genus Maclura (Moraceae) consists of twelve species occurring in Asia, Australia, Africa, and the Americas. Maclura pomifera, the only North American native, is a dioecious tree with a limited native range encompassing parts of four US states. The large, fleshy fruits of this species are not eaten by any extant frugivores, leading to the assumption that M. pomifera may have been previously dispersed by extinct megafauna. Morphological and sequence data will be acquired for the twelve Maclura species and the other taxa considered part of its subfamily in order to determine a phylogeny for the group. This phylogeny will be used to infer the evolutionary and biogeographical history of the group, to explore the possibility that M. pomifera was once biotically dispersed, and to clarify the current taxonomy of the genus and its subfamily.

McAloon, Michael
Elephants, tapeworms and mites: the life cycle of Anoplocephala manubriata revealed
A total of 602 oribatid mites (Acari: Oribatei) comprised of 23 species were collected during November 1997, from the Kodanadu Forest Range, Ernakulum District, Kerala, India. Samples of soil and detritus including the elephants' dried palm leaf bedding were taken from around the dung piles of elephants known to be infested with Anoplocephala manubriata and placed in Berlese funnels. The oribatid mites were cleared with Hoyer's medium and slide mounted to determine presence of ingested cestode eggs or developing cystercercoids within the mites. These species of oribatids were found to contain at least one immature life stage of A. manubriata: Galumna flabellifera orientalis, Scheloribates latipes, S. praeincisus, Xylobates seminudus, X. triangularis. The intermediate hosts and the lifecycle of Anoplocephala manubriata had not previously been reported.

McManus, Hilary(1), E.L. Taylor(2), T.N. Taylor(2) and L.D. Boucher(3).
(1)Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269 USA
(2)Department of Ecology and Evolutionary Biology and Natural History Museum-Biodiversity Center, University of Kansas, Lawrence, KS 66045 USA
(3)Department of Biology, University of Nebraska-Omaha, Omaha, NE 68182 USA.
A new stem with unusual anatomy from the Triassic of Antarctica
An axis with a complex vascular system is detailed from Middle Triassic silicified peat of the Fremouw Formation of Antarctica. The diameters of the four specimens identified range from 1.4 to 1.7 cm; the longest specimen is approximately 12 cm. In transverse section, the vascular system consists of segments that occur as single traces, or are connected in the center and anastomose at varying levels within the stem. Each segment contains a bifacial vascular cambium. The secondary tissues of each segment surround a central area of parenchyma and small tracheids presumed to represent primary xylem. Traces are produced by the segments near the periphery of the axis and consist of radially arranged secondary xylem, some with apparent external periderm. The absence of leaves and reproductive organs leads to uncertain phylogenetic relationships. We are unaware of any Triassic plants with this type of vascular tissue organization, and those plants with a similar type of arrangement occur only in the Devonian and Carboniferous. Possible phylogenetic affinities with the Cladoxylales and Lycophyta are examined, but the anatomical differences, along with stratigraphic age, preclude formal assignment to any known taxon at this time.

Moody, Michael and Donald H. Les
Foiled again: hybridity in invasive hydrophyte populations
Invasive water milfoil (Myriophyllum) populations in North America have been assumed to represent nonindigenous species that have become ecologically aggressive outside their native range. Morphological characterization of M. heterophyllum (New England) and M. spicatum (North America) invasive populations has been ambiguous relative to closely related Native North American milfoil species. Molecular studies of these presumed "M. heterophyllum" and "M. spicatum" populations have revealed widespread polymorphisms in biparentally inherited nrDNA sequences. Subclones of these polymorphic regions revealed the occurrence of distinct sequences matching those acquired from both native and nonindigenous North American species. These data clearly demonstrate that invasive water milfoil populations in North America have resulted from hybridization between nonindigenous and native species. These observation indicate that invasivity in these aggressive aquatic weeds may be linked to heterosis maintained by vegetative propagation.

O'Donnell, Brigid
The development and evolution of gill morphology in mayflies
The diversity of insect appendages has played an important role in their evolutionary success. Appendage modifications constitute the basis of this success in many insect lineages; for example, the immense diversity and specialization of mouthparts has allowed insects to capitalize upon almost any imaginable food source. An even more striking example involves the evolution of wings, a key innovation in appendage diversification since extant winged insects constitute over two-thirds of all life on the planet. Mayflies (Order Ephemeroptera) are morphologically and physiologically most similar to wingless insects and indeed have been called 'flying thysanurans'. Moreover, mayflies are likely to be the sister taxon to all other winged insects, and so occupy a key phylogenetic position hinging on the transitory period when wings and flight evolved in insects. Studies of these primitive insects can yield information on the evolution of wings and flight and the nature of the massive radiations of winged insects. Mayflies are particularly interesting because they possess abdominal gills, which have been hypothesized to be serial homologues of wings and which have undergone dramatic morphological modification in the group. Much of the variation is built upon the branching of gills and modification of the branches. Branched gills occur widely in mayflies and this structural modification may have been a key innovation that allowed mayflies to colonize a plethora of aquatic habitats. Using mayflies, I propose to explore the evolution of branched gills by means of a comparative analysis of gene expression and a comparative analysis of gill morphology.

Owen, Patrick
The evolution of aggressive calls in chorus frogs, genus Pseudacris
Advertisement and aggressive calls are two types of signals that influence mating success in frogs. Advertisement calls increase fitness through mate attraction, and aggressive calls indirectly increase fitness through warding off competitors. Comparisons among closely related species suggest that aggressive signals are more similar than advertisement signals. This may be due to the lack of directional selection on aggressive signals or to convergent evolution. Chorus frogs have a well supported phylogeny which makes them an excellent group for studying this aspect of communication. Advertisement calls are diverse in chorus frogs, evolving from single note calls in basal species to pulsed calls in derived species. Previously, the only known aggressive calls were pulsed calls in P. crucifer which has single note advertisement calls. I describe aggressive calls for the first time in four species of chorus frogs. P. streckeri, like P. crucifer, is a basal species with single note advertisement calls and pulsed aggressive calls. P. feriarum, P. nigrita, and P. triseriata are derived species, and all have pulsed advertisement calls as well as pulsed aggressive calls. My current results suggest that aggressive calls are more similar than advertisement calls in chorus frogs, and I expect future work with more frogs in this genus to show the same pattern.

Pereira, Jose
Using geographic information systems to document fish habitat use
I outline an effort to identify essential fish habitat in Long Island Sound for a species of recreational importance, the tautog. Geographic information systems are an excellent tool for identifying geographical features with areas known to contain congregations of fish. Using this tool, I was able to link two different databases on Long Island Sound. One is a map of surficial sediment coverages; compiled by the U. S. Geological Survey, it is based on side scan sonar, ground-truthed with sediment grab collections. The other is a biannual (spring and fall) trawl survey of 22 species conducted by the State of Connecticut DEP Marine Fisheries Division. The survey is conducted as a stratified random design, using a grid of 1X2 nautical mile sampling boxes. Strata in the design are based on water depth and bottom type. Importing catch data into ArcView, I queried the trawl database to identify which boxes of the sampling grid yielded catches of each species of interest. These boxes were then used as "cookie cutters" to do a "clip" on the underlying sediment layer. The clipped layer can then be compared to the Sound as a whole to determine whether the fish are selective in their habitat use. Finer-scale approaches are being explored with existing databases; for example, sediment clips can be taken for the actual trackline of each trawl sample. Another effort in future work is to gather individual habitat use information by tracking fish with acoustic transmitters. Sediment clips can then be based on minimum convex polygon estimates of an animal’s home range.

Plowes, Nicola
Small warriors: the costs of waging war
Many territorial animals engage in lethal combat, including humans and ants. Recent interest has arisen in the application of Lanchester's (1916) theory of combat to understand the mechanisms behind different battle strategies in ants. Lanchester's Laws have been implicated in the various strategies of slave-raiding ants, army ant and invasive ant species. We are currently investigating the ability of Lanchester's laws to accurately predict the outcome of staged, escalated battles between ants (specifically Solenopsis invicta, the Red Imported Fire Ant), both with empirical data and mathematical models.

Reyda, Florian
Tapeworms of tapeworms of potamotrygonid stingrays of southeastern Peru
A preliminary survey of the parasites of freshwater stingrays (Potamotrygonidae) of southeastern Peru was recently undertaken. Approximately eight species of onchobothriid and phyllobothriid tapeworms (Cestoda: Tetraphyllidea) were collected from the spiral intestine of the stingrays Potamotrygon motoro, Potamotrygon castexi, and Paratrygon aireba. Initial light microscope examination of whole-mounted tetraphyllideans from each stingray species revealed the presence of inclusions that appear to be independent in origin from the host tapeworm. Serial sections of infected tapeworms indicated that the inclusions are other tapeworms, or hyperparasites. The presence of four suckers, an apical organ, and a cyst wall qualifies the hyperparasitic tapeworms as members of the order Proteocephalidea or Cyclophyllidea. Molecular sequence data of hyperparasite 28S rDNA matched known sequences for the Proteocephalidea. Although hyperparasites of proteocephalideans are known, this is the first record of a proteocephalidean from a tetraphyllidean.

Ridge-O'Connor, Gale
Heteroptera thoracic endoskeleton
My research is looking at the interior thoracic surfaces of the exoskeleton in the suborder, Heteroptera. I have found distinct muscle attachment, throacic strengthening and soft organ guiding structures located on the inner walls of the thoracic exoskeleton. This region I have called the endoskeleton. There are many features which lend strongly to character analysis, which might become useful as an additional tool in phylogenetic analysis.

Sezen, Uzay
Seed-mediated gene flow and parentage in a regenerating second-growth neotropical forest
The regeneration of genetically diverse second-growth forests requires successful seed dispersal and seedling recruitment into recovering areas. We know virtually nothing about the spatial scale and diversity of seed dispersal of the individuals that colonize young, second-growth forests. Conventional seed trapping methods can quantify seed rain, but do not provide any insight into the parental pedigree, the distances traveled by seeds, or the spatial distribution of offspring from particular seed parents. One approach is to compare genotypes of mapped seedlings with those of potential parental individuals to reconstruct actual seed dispersal shadows. DNA based molecular analysis can match offspring to their parents and can be used to reconstruct the genetic history of colonization of new sites.

Shannon, Robynn
Phenology and life history of the brown algae Petalonia fascia and Scytosiphon lomentaria in New Hampshire
The marine brown algae Petalonia fascia and Scytosiphon lomentaria have an unusual life history that has been difficult to interpret, particularly regarding the role of sexual reproduction. Results from culture experiments indicate that environmental factors can determine which life history stage will be produced, and allow predictions of the time of year each stage might be expected to occur on the shore. Seasonal patterns of abundance and recruitment of both species were studied in New Hampshire and compared to predictions based on culture experiments. The ability of Petalonia fascia to reproduce sexually was investigated.

Sikes, Derek
Bibliographic taxonomy (a.k.a. The Valley of the Shadow of Death): Lessons from the other side
The production of a bibliographic taxonomic catalog can be an intimidating task. The process of monographing a taxon, however, requires a thorough knowledge of the history of the group. Elucidating the evolutionary history of a group is arguably more exciting than reconstructing the literary history; however, both endeavors are integral components of systematic study. I will present arguments for bibliographic taxonomy and thoughts on what I perceive as problems in our current name-tracking system.

Townesmith, Andrew
Linguistic artifacts: etymological patterns in the Native American origins of English terms for New World plants and animals
Of an estimated 1800-2000 languages spoken in the New World at the time of European contact, 2/3 are already extinct or moribund. Due to high mortality from European diseases and forced cultural assimilation, many of the earliest contacted groups lost their languages before any record was made. However, elements of these languages persist in English (and other European languages) terms for plants and animals unique to the New World. Borrowed words are not distributed equally between all Native American languages, but reflect the history of European contact. Languages spoken in the Caribbean (Taino, Arawak, Carib), along the Atlantic coast of Brazil (Tupi, Guarani), and the North-eastern United States (Algonquin, Narragansett) have contributed a disproportionate number of words to the English language. From a sample of 117 English words with etymological origins in 33 Native American languages, 54% were derived from 5 (15%) languages. These languages are Nahuatl (Aztec), Tupi, Quechua (Inca), Taino and Carib. Taino and Nahuatl words are especially prevalent in English terms for economically important, domesticated plants, while Tupi words refer primarily to tropical animals. The vast majority of languages, particularly those spoken by inland peoples, have contributed no words to English beyond place names or terms for neighboring tribes.

Wickett, Norman
Systematics and molecular evolution of the parasitic liverwort genus Cryptothallus
Cryptothallus is a genus of simple thalloid liverwort (Jungermaniopsida, Metzgeriales) unique among bryophytes in that it is achlorophyllous. Two species have been described; Cryptothallus mirabilis Malmborg (1933) is known from Northern and Central Europe and Greenland, is usually subterranean, growing in Sphagnum or other bryophyte litter. Cryptothallus hirsutus is known only from Costa Rica and differs slightly from C. mirabilis in both sporophytic and gametophytic characteristics. The genus is described as parasitic, obtaining its organic nutrients via a fungal (basidiomycete) endophyte. Other simple thalloid liverworts are associated with basidiomycetes, yet remain photosynthetic. It has been suggested that Cryptothallus is simply an achlorophyllous species Aneura, based on morphological similarities. The aim of my research is to determine the systematic position of Cryptothallus, based on molecular and morphological characteristics. In addition, I intend to examine the molecular evolution of its chloroplast genome, looking for deletions or losses in function of particular genes.

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