Spring Semester 2016
Monday, January 25, 2016
12:00 PM in Harborwalk West 305
Success in nature and sport: exploring the biological basis of excellence in physical activities
All physical activities rely on a complex assortment of anatomical, physiological, motor and behavioural traits. Discovering the determinants of individual success in physical activities has become central to the study of adaptation because it allows one to understand the coevolution of organismal form and function in natural populations. In a similar way, determining the combination of traits most responsible for success in human functional tasks is of enormous interest to the sports industry for discovering and developing athletes and the health sciences for facilitating improved pathways of recovery following injury. But despite the parallels in research programs between the natural and health sciences, each discipline has operated in relative isolation. In this seminar, I will explore the parallel lines of research that explore the determinants of success in physical activities in two very different but complimentary study systems: (i) natural populations of the small carnivorous marsupial, the northern quoll (Dasyurus hallucatus) from tropical Australia, and (ii) semi-professional soccer players. The northern quoll is the world’s largest semelparous mammal, which means mating is highly synchronous, males live for only one year, and all males undergo die-offs soon after reproduction. Given the importance of procuring mates in such a short period (approx. 2 weeks), the ability for males to win fights and cover long distances to find reproductively mature females is presumably of critical importance. Female quolls live for two to three years and their die-off occurs after the young are weaned - which is around four months after the mating season. Soccer is also ideal for a integrative studies of success because we can readily identify, isolate and quantify many of the possible underlying determinants of success among large numbers of individual players. Soccer is the world’s most popular team sport and is played by an estimated 240 million registered competitors and watched by more than a billion people worldwide. Using these two very different study systems, I will discuss the implications of my work for understanding the evolution and ecology of physical performance in nature.
Monday, February 8, 2016
4:00 PM in SSMB Auditorium
Special Darwin Week Seminar
Where'd you get those peepers? How eyes and other complex organs evolve
A century and a half ago, the origin of complex organs such as the human eye seemed explicable only in terms of supernatural design. Darwin provided the basic framework for a scientific answer to the question in The Origin of Species, but he nonetheless admitted that thinking about the eye gave him a "cold shudder". A great deal of new information has arisen in the roughly 150 years since Darwin first addressed the problem of eye evolution -- including insights from genetics, molecular biology, comparative anatomy, developmental biology, and evolutionary theory. This talk provides an overview of both the concepts and current data that provide an understanding of how eyes and other complex organs come to be.
Monday, February 22, 2016
12:00 PM in SSMB 138
Does evolutionary convergence of ecomorphology result in convergence of performance capacity? A test using Australian and North American lizards
Convergence of morphology and ecology is a well-described evolutionary phenomenon. Whole-animal performance capacity is a key linkage between morphology and ecology; thus one might expect convergence in morphology and ecology to also be linked to convergence in performance capacity. Previous work has demonstrated evolutionary convergence of morphology and ecology between Australian agamid lizards and North American iguanid lizards. Furthermore, several species pairs within these lineages also exhibit convergence in ecology and morphology. Therefore, we hypothesized that locomotor performance and function has converged in these groups. To test this hypothesis, we measured locomotor morphology and performance in 12 Australian agamid species and 9 North American iguanid species. We tested for convergence in function by estimating partial regression coefficients between morphology and performance using phylogenetically generalized least squares. We then assembled those coefficients into an F-matrix for each clade and tested the relationship between F-matrices. Next, we generated a performance space for all species to test clade-wide convergence. Finally, we used several statistical metrics coupled with evolutionary simulations to test for transcontinental convergence of performance for each species pair. We found that Australian agamids and North American iguanids occupy similar regions of performance space. While a few species pairs converged in locomotor performance, most predicted pairs did not converge. Additionally, F-matrices were not related suggesting that the functional link between morphology and performance evolved differently in these lizard clades. Overall, these results suggest that the strong pattern of convergence known for ecology and morphology in these lizards has not resulted in a strong pattern of convergence in performance.
Monday, February 29, 2016
12:00 PM in SSMB 138
Student persistence in science: Elucidating critical features of undergraduate reserach experiences
Lisa Corwin, University of North Carolina, Chapel Hill [flier]
Engaging in undergraduate research is associated with numerous student outcomes, including increased self-efficacy, persistence in a biology major, and pursuit of a career in science. Course-based Undergraduate Research Experiences (CUREs) increase students’ access to research experience by involving all students enrolled in a course in an active research project. Recent studies describing student outcomes of CUREs help to evaluate CURE efficacy, but do not describe what makes CUREs distinct from other lab learning experiences. Knowledge of the variation in CURE instruction and activities is essential to determine how and why CUREs work in order to inform future course design. Recently, an expert panel theorized that CUREs comprise five course elements. CUREs provide opportunities for students to (1) engage in science practices (e.g., collect and analyze data), (2) make discoveries, (3) engage in work that has relevance outside the classroom, (4) collaborate, (5) and iterate (e.g., revise or repeat experiments). We developed an instrument, the Laboratory Course Assessment Survey (LCAS), intended to measure elements 2 through 5. Data from 213 students in biology courses, including CUREs and traditional labs, were used to characterize the psychometric quality and utility of the LCAS. This talk will discuss the development of this instrument, its psychometric properties, and results from initial data collection in biology laboratory courses. The LCAS can be used to assist and assess laboratory course design and to determine how course design relates to student outcomes.
Monday, March 21, 2016
12:00 PM in HWWE 305
Even the losers: consistent individual aggression in song sparrows & snapping shrimp
Behavior can be a remarkably plastic phenotype: for example, game theory predicts the expression of aggression to depend on variables such as resource value and relative competitive ability, and by and large, empirical data support these predictions. Plasticity in aggression is likely to be adaptive; nonetheless, across a wide range of taxa, individuals differ consistently in aggressive behavior, both within and across contexts. Understanding the causes and consequences of such limits to plasticity is thus critical to understanding the evolution of aggressive behavior. During my sabbatical, I explored the latter in song sparrows and the former in snapping shrimp.
Monday, April 4, 2016
12:00 PM in HWWE 305
A tale of two communities: The ecology of a vertically stratified butterfly assemblage
Tropical butterfly communities are notable for their spectacular species richness. Here, I will examine the community structure of fruit-feeding Nymphalid butterflies based on four long-term trap studies carried out in the neotropics. Canopy and understory differ substantially in their species composition. There is a strong phylogenetic signal, with some lineages almost exclusively foraging in either canopy or understory habitats. Overall, there are very few species that can be reliably found in both strata. Beyond the vertical partitioning of species occurrence, the dynamics of community composition varies greatly between canopy and understory. Beta-diversity, or species turnover, is much higher in the canopy compared to understory both spatially and temporally at each of the study sites examined. We compared the community composition of intact rainforest with a comparatively more homogeneous abandoned banana plantation. Although richness and diversity was lower at the plantation site, the pattern of greater species turnover in the canopy compared to understory habitats remained. There is also evidence that for some species there is vertical population structuring.
Monday, April 18, 2016
12:00 PM in HWWE 305
Evolution in a Biodiversity Hotspot: Wild 'Geraniums' in South Africa
The genus Pelargonium, ancestor to our household ‘geranium’, contains around 300 species and most are endemic to South Africa. The genus contains a remarkable diversity of growth forms, leaf shapes and floral syndromes. In a series of studies, we have examined patterns of diversification in the genus for leaf shape, photosynthesis and water relations, and examined whether trait values are associated with environmental gradients. We also assessed amounts and direction of phenotypic plasticity in a common garden experiment, revealing that plasticity itself has evolved as well within this genus.