Graduate Research Symposium 2008
Saturday, March 1st 2008
|10:30-11:00||Coffee & Breakfast|
|11:00-11:15||Gregory J. Anderson|| Welcome |
By the Vice Provost for Research and Graduate Education and Dean of the Graduate School
|11:15-11:30||Susan G. Letcher||Community phylogenetic structure of secondary and old-growth forests in northeastern Costa Rica|
|11:30-11:45||Tobias Landberg||Allometric engineering of salamanders|
|11:45-12:00||Frank Smith||A Functional Analysis of the Homeobox Protein Dll-B in the Ascidian Ciona intestinalis|
|12:00-12:15||Lori Benoit||A molecular genetic study of Hydrilla verticillata, an invasive aquatic weed|
|12:15-12:30||Leah Brown-Wilusz||Hatching Plasticity in Spotted Salamanders|
|2:00-2:15||Suegene Noh||Are hybrid lacewings attractive?|
|2:20-2:45||Adam Wilson & Natalia Norden||R Statistics: Don't be scared!|
|2:45-3:00||Kristiina Hurme||Tadpole schooling in Leptodactylus insularum|
|3:00-3:15||Katherine Shaw||Sneaky Threespines: Characterizing geographic variation of sneaking behavior in Gasterosteus aculeatus of the Pacific Northwest|
|3:15-3:30||Bryan Connolly||The interaction of deer and invasive plant species in forests of the northeast|
|4:00-4:15||Cory Merow||America's Next Top Ecological Model|
|4:15-4:30||Geert Goemans||Eel sushi, delicious or deadly?|
|4:30-4:45||Nicholas Tippery||Quality or quantity? The challenge of sexual versus vegetative reproduction in the dioecious aquatic plant Nymphoides cordata (Menyanthaceae)|
|4:45-5:00||Jessica M. Budke||Examining the calyptra-sporophyte interaction in the moss Funaria hygrometrica|
|5:00-5:15||Karolina Fucikova||Systematics of the Green Algal Genus Bracteacoccus|
|Cory Merow||Cooperative Aliens Invade New England!|
|Nicholas Tippery||Reconstructing phylogeography using ancestral area likelihood analysis|
|Maria Pickering||Green Grads|
The EEB Graduate Student Symposium is an all day event where graduate students present their research to other graduate students and faculty. Any EEB graduate student can present: BSMS, masters, PhD, old and new students. New graduate students usually present research ideas or preliminary data, while those more ‘seasoned’ students present their most recent results, often in preparation for upcoming spring and summer meetings.
This year we are trying out a new phenomenon, Speed Talks, in addition to our regular 15min presentations. There will be an almost unlimited number of 15min talks, and a limited number of speed talks. We would like to invite all EEB graduate students to give a 15min talk. Speed Talks have been seen at several large meetings over the last year (playing off the speed dating idea). These talks will be 3min presentation, PowerPoint optional. They are ideal for sharing side projects, amazing images or videos, great opportunities that others should take advantage of, or any other interesting things that you would like to share. Since this is new, we are going to have one small section of them in the afternoon. We envision these being given in addition to a regular 15min talk. If you are interested in participating in this section please let firstname.lastname@example.org know, the actual number of these talks is still flexible but we will take these on a first come basis
Green algae (Chlorophyta) are a morphologically heterogeneous group that is undergoing considerable revisions at present. Especially in coccoid genera, there have been striking cases of polyphyly, when species originally placed in one genus were shown to belong to up to three different classes. The coccoid chlorophycean genus Bracteacoccus Tereg was until recently considered monophyletic, but with the advent of new molecular data, it no longer appears as such. Work is being conducted with the ultimate goal of monographing the genus Bracteacoccus.
We studied hatching plasticity in spotted salamander (Ambystoma maculatum) embryos by exposing them to combinations of egg and larval predator cues. Animals exposed to egg predators hatched out earlier regardless of whether larval predators were present or not. Animals exposed to larval predators only had the largest tail areas and survived longest in lethal predation trials. However, animals exposed to both predators had intermediate tail morphology and survival times indicating costs of hatching out early. The early effects of hatching plasticity were no longer detectable at metamorphosis indicating there are no long-term costs of hatching plasticity on growth or developmental rates.
Susan G. Letcher
The emerging field of community phylogenetics permits ecologists to incorporate phylogenetic information into the study of ecological processes. Given the widespread evidence for phylogenetic niche conservatism (the propensity for closely related species to share the same suite of traits), phylogenetic structure in community data sets can be used to infer assembly processes. Phylogenetic clustering is generally interpreted as evidence for abiotic filtering, in which the match between organism and environment drives community assembly. Phylogenetic overdispersion is interpreted as evidence for strong biotic interactions, either in the form of competition between closely related species or facilitation between distantly related species. Currently, the only published work on community phylogenetics during succession has been conducted in microbial systems. I examined the phylogenetic structure of a chronosequence data set of woody vegetation from 30 sites in northeastern Costa Rica, ranging from 10 yrs to old growth. I found significant phylogenetic overdispersion in forests of all ages, but the scale at which I detected overdispersion varied along the chronosequence. At young sites (<20 yrs), the species pool for the age class showed overdispersion but individual sites showed little or no phylogenetic structure. In older sites, the species pool showed no phylogenetic signal, but individual sites showed strong overdispersion. These data suggest that biotic filtering operates throughout the successional process, and becomes especially strong as the forest matures.
The Neotropical frog Leptodactylus insularum exhibits tadpole schooling and female parental care. Leptodactylus insularum breeds in temporary ponds and the tadpoles develop quickly, reaching metamorphosis in only 17 days. In order to grow and develop quickly, L. insularum tadpoles maintain high activity and feeding rates. Increased activity in tadpoles may increase predation risk, and L. insularum tadpoles may overcome this cost by forming dense aggregations. In the field L. insularum tadpoles are only found in these dense schools, and these schools continually move throughout the aquatic environment, often led by the attending female. Contained schools rapidly deplete their food resources, suggesting that competition for food within these aggregations is high. I performed a mesocosm experiment to examine the effect of food level and density on tadpole growth and development. I found that high density and/or low food infer a cost to tadpoles, by delaying both growth and development rates. Further work will focus on whether this cost might be higher without the coordinated schooling behavior of the aggregations.
Adam Wilson & Natalia Norden
We will give an overview of the R Project for Statistical Computing and discuss the many advantages of conducting analysis in the R framework. These include ease of manipulating data, presentation quality graphics, powerful and flexible statistics, ability to archive methods through the use of scripts, spatial data analysis and linkage to GIS, availability for most operating systems, and no-cost availability.
I propose to investigate variation in a conditional male mating behavior and provide an initial assessment of the environmental and genetic underpinnings of sneaking behavior in Pacific Northwest threespine stickleback populations (Gasterosteus aculeatus L.). Preliminary investigation suggests regional differences in the propensity of male sneaking behavior, an alternative tactic that allows males to escape strong intraspecific mate competition by fertilizing eggs in the nests of other males. This study system offers an intriguing opportunity to evaluate the patterns of expression of alternative mating tactics among populations rather than focus on variation within populations under variable environmental conditions. By utilizing methods to investigate both potential genetic and environmental components underlying phenotypic variation in oceanic (ancestral) and freshwater populations across regions, this work will enhance our evolutionary insight into the extent by which ancestral plasticity has shaped geographic variation in sneaking propensity.
The floating-leaved aquatic plant Nymphoides cordata (Menyanthaceae) is one of only two Nymphoides species native to North America, and one of only four dioecious Menyanthaceae species. Dioecy, the extreme gender specialization whereby individual plants are either staminate (male) or pistillate (female), has evolved independently multiple times in angiosperms and is considered advantageous for promoting outcrossing, i.e., sexual reproduction with genetically dissimilar individuals. In addition to being dioecious, N. cordata is capable of vegetative reproduction, a life history trait that is relatively common among aquatic plants. Although vegetative reproduction can increase population size without pollination or seedling establishment, it can lead to reduced genetic variation because all vegetative offspring are genetically identical to their parent. The interplay between vegetative reproduction (which generates genetically identical offspring) and sexual reproduction under dioecy (which requires genetically dissimilar individuals) presents an interesting challenge for N. cordata, which must balance population increase against potentially reduced genetic variation. Several populations of N. cordata in Connecticut were studied to characterize their relative degree of sexual versus vegetative reproduction. Future work using microsatellite markers will also be discussed.
Jessica M. Budke