John Swallow - US grants

arthropod genetics; genetic polymorphism; sex behavior; genetic mapping; sperm motility; Diptera;

A grant has been awarded to the University of South Dakota Department of Biology, under the supervision of Drs. Nepokroeff, Britten, Helenurm & Swallow, to acquire automated genetic analysis instrumentation. The equipment will be used for automated DNA sequencing, genetic fragment and genotyping analysis (e.g. microsatellite detection, DNA finger-printing using AFLPs). The equipment will be housed in the Biology Department, and will be used by an additional 17 faculty from USD's Departments of Biology and Basic Biomedical Sciences. The acquisition of this equipment at USD is especially significant because there is currently no such facility on campus, and no high-throughput facility in the state of South Dakota.
Researchers in Biology at USD will address a number of important questions in evolutionary genetics, conservation biology and systematics using the genetic analyzer. Specific projects to be addressed by Dr. Nepokroeff include the systematics of the carnation family, Caryophyllaceae, using molecular phylogenetic analysis of several different DNA sequences and phylogenetic approaches to study biogeography, (colonization and dispersal) in Pacific island species of the tropical shrub genus Psychotria (one of the most species-rich genera of flowering plants). Additionally, she will study conservation and population genetics of several Hawaiian plant lineages using AFLP and microsatellite markers. Dr. Britten plans to address population genetic structure and genetic variability of several Federally endangered species. He will be investigating the effects of population fragmentation through habitat loss and historical sylvatic plague infections in Black-tailed prairie dogs using AFLP and microsatellite analysis. Additionally, he plans to examine genetic variation in trumpeter swans and sandhill cranes. Dr. Helenurm will address population genetics and evolution of insular endemic plants. He will use DNA finger-printing methods, e.g., microsatellite and AFLP markers to examine levels of genetic variability in several species of flowering plants endemic to California's Channel Islands, many of which are endangered. He will also use AFLPs and DNA sequences to examine within-species (or "phylogeographic") relationships for plant species in the Channel Islands, a system which is poorly known. Dr. Swallow will address questions concerning correlated evolution of morphological, behavioral and physiological traits in stalk-eyed flies (family Diopsidae), wild relatives of the fruit fly. He will use DNA sequences for reconstructing phylogenetic relationships among species and populations of stalk-eyed flies. Secondly, he will use DNA markers (AFLPs) in a QTL study to determine the number of genes involved in traits related to species recognition and mate choice.
The equipment will be used in original research by faculty, postdoctoral researchers, graduates and undergraduate students at USD, will be integrated into three courses in the USD curriculum. The equipment will also be incorporated in several existing summer programs, geared to give research experiences to area minority high school students and their teachers. The new equipment and proposed programs are anticipated to serve at least four area colleges with research expertise and experiences, in addition to the USD community. Acquiring an on-site facility will enhance the PI's competitiveness for federal research funds and attract new faculty and graduate students to USD's growing research programs. Thus, a genetic analyzer facility will have an enormous impact on the quality of research and educational programs at USD, will allow the PIs to integrate teaching and research at a high level, and will enrich the USD community in a diversity of ways.

This symposium will be presented at the annual meeting of the Society for Integrative and Comparative Biology to be held in New Orleans, January 4-8, 2004. The symposium, is of broad interest to scientists in the fields of comparative, ecological, and evolutionary physiology, as well as population and evolutionary biology. This symposium will introduce artificial selection as a powerful but underutilized tool by providing definitions, background, and examples, and by including sufficient explanation of methodological issues to allow those new to the field to contemplate implementation of a selection experiment. Symposium speakers have been chosen to cover a range of physiological systems and to illustrate a diversity of model organisms, including vertebrate, invertebrate, and microbial systems. Rapid response has been observed in many physiological systems across a wide array of organisms. Results from selection experiments presented in this symposium will illustrate the power of direct comparison between replicated selected and unselected control lines for drawing conclusions about the adaptive significance and the mechanistic basis of responses to selection. The Society for Integrative and Comparative Biology (SICB) is a scientific society of about 2,200 members. It is the premier society for integrative and comparative biology in this country, and among the leading such societies in the world. It sponsors an annual meeting in North America, at which member-originated symposia are a major feature. In recent years this meeting has attracted approximately 1,200 attendees, both SICB members and non-members. A noteworthy feature of this meeting is its emphasis on young investigators. Typically, more than half of those in attendance are Ph.D. students, postdoctoral fellows, and young faculty. This symposium showcases presentations by young scientists (8 of 15 speakers) and women in science (4 of 15 speakers). Thus, SICB symposium speakers receive exposure to a cross-section of the relevant scientific community and a strong representation of young scientists. There are a number of symposia, workshops and special programs planned for the New Orleans SICB meeting, providing an excellent opportunity for the symposium to reach a broad audience.

physiology; exercise; laboratory rat;

stress; neurochemistry; exercise; amines; behavioral /social science research tag;

CAREER: PERFORMANCE AND FITNESS CONSEQUENCES OF INSECT ORNAMENTS
JOHN G. SWALLOW
UNIVERSITY OF SOUTH DAKOTA

Sexual selection is responsible for much of the morphological diversity among animals and is often expressed in the form of male ornamental displays. Sexual selection theory indicates that these display traits do not come without costs, such that the displays and their costs are countered by natural selection. Stalk-eyed flies provide the ideal model system to test for costs and tradeoffs related to male ornamentation. All species in this extraordinary family display exaggerated head morphology, with eyes and antennae displaced at the end of long stalks, and interspecific variation in eye span can be more than ten-fold. Furthermore, all available evidence indicates that eye stalks are critical sexual signals used in both male-male competition and female choice. This study will examine the effects of elongated eye stalks on flight performance and survivorship of stalk-eyed flies to assess whether these effects run counter to the effects of sexual selection. To achieve this goal, the PI will integrate information from three distinct avenues of research. First, to establish a link between morphology and performance, variation in eye span and locomotor performance will be measured in a single species, Cyrtodiopsis dalmanni, to test for trade-offs between secondary sexual traits and adaptations for flight. For this study, lines of C. dalmanni that have been bidirectionally selected for increased and decreased eye span will be used to increase the natural variation seen in this species. Direct measurements of acceleration, speed and maneuverability during flight will be made using computer-integrated high speed video cameras. Additionally, load lifting capacity and energy used during flight will be measured. Second, the fitness consequences of impaired flight performance will be directly measured in a series of predation avoidance experiments in greenhouse enclosures. Third, patterns of correlated evolution between morphology and flight performance measured on many species within the family Diopsidae will reveal evolutionary consequences of sexual selection. If eye stalks impair locomotor ability, compensatory changes in body design are predicted to evolve within the family to reduce the locomotor cost. Such compensatory changes would indirectly suggest that such reduction in performance was selectively important. This research program incorporates multiple disciplines and will certainly result in new insights regarding interactions between the costs of locomotion and the evolution of secondary sexual ornaments. The PI's educational activities will focus primarily on disadvantaged pre-college students from Native American reservation schools and rural schools. Both of these groups, particularly Native Americans, are traditionally underrepresented in both college and the sciences. South Dakota has both a large Native American population (~ 10%) and a large rural population. Through cooperation with the instructors affiliated with the Mobile Science Laboratory (MSL), the PI will develop a contribution on "Sexual selection and insect diversity: secondary sexual ornaments" for the MSL. Outreach projects developed for the MSL will expose K-12 students from Native American reservation and rural schools to the process of science and discovery. This outreach program has the potential to positively influence thousands of people throughout the state of South Dakota.

Abstract

Aggressive syndromes, in which some individuals are consistently more aggressive than others over a range of contexts, have been documented in multiple species. Although the expression of aggressiveness should be favored in male competition, such behaviors may be disadvantageous in interactions with predators, offspring or mates, creating evolutionary trade-offs. Understanding the physiological mechanisms that influence aggressive interactions may help us understand why some individuals express aggression in inappropriate contexts in ways that are detrimental to survival and reproduction. Stalk-eyed flies provide an ideal model system to investigate both the physiological mechanisms and the reproductive and survival fitness consequences of aggressive syndromes because males in many species use their exaggerated head morphology in dramatic, ritualized aggressive displays in different contexts, including male competition, reproductive display, and predator-prey interactions. The proposed research uses behavioral and pharmacological approaches to test whether the maintenance of aggression levels displayed by male stalk-eyed flies across these contexts is mediated through changes in the function of two key neurotransmitters, serotonin and octopamine. Students ranging from pre-college to graduate levels in Colorado and South Dakota will participate in these studies, providing them with meaningful and valuable research experiences. These experiences are important to encourage students to pursue careers in science. Because children are often first exposed to the formal process of science and discovery in public schools, an effective scientific educational program must include outreach to both children and teachers. The investigators will help train the next generation of Colorado science teachers by exposing them to the process of scientific discovery through immersion in project-based internships. Exposure to project-based laboratory experiences will better prepare these teachers to inspire the next generation, affecting potentially thousands of children. The investigators will also develop and deliver hands-on laboratory exercises for students attending science camps in South Dakota.


Data will be made available for free access following publication of results. Data will be available via ResearchGate (ResearchGate.net) and linked with published articles.

Evolution is responsible for many bizarre and showy physical characteristics (i.e. ornaments) in males, but how they remain reliable indicators of male quality remains controversial. Current hypotheses indicate that ornaments are costly to their bearers, however studies testing for decreased locomotor performance or decreased survival or reproductive success (i.e. Darwinian fitness) as a result of ornaments have been inconclusive. For large ornaments, selection should favor evolution of traits and behavior that offset costs of ornaments, thus concealing their true costs. Stalk-eyed flies provide an ideal model system to test for costs and tradeoffs related to male ornamentation due to their exaggerated head morphology, with eyes displaced at the end of long stalks. These flies exhibit considerable variation in muscle and wing size, compensatory traits that may offset the inertial effects of eye stalks on flight performance. This research incorporates biomechanical and flight performance experiments to characterize compensatory ability in relation to ornament size, and determine how the interaction of ornaments and compensatory traits impact flies' ability to evade predators and reproduce. The proposed research has the potential to significantly revise our understanding of how exaggerated traits evolve and also improve our understanding of biomechanical compensation for ornaments and inform bio-inspired engineering efforts such as miniature drones. This research will provide technical training and professional development to a post-doctoral scholar, a technician and graduate and undergraduate students. Outreach efforts at both campuses will provide STEM education to elementary students and training to K-12 educators.

This research employs a novel theoretical and empirical approach to assess the costs of ornaments by considering how compensatory ability in relation to relative ornament size affects the interaction between viability and fecundity. Three distinct avenues of research will be integrated to achieve this goal. First, using species of stalk-eye flies within the family Diopsidae, patterns of correlated evolution between eye stalks and compensatory traits will reveal the macroevolutionary consequences of selection and test the hypothesis that relative ornament size will be positively correlated with the relative size of compensatory traits within and across species. Second, a series of flight performance, maneuverability and predator-avoidance experiments will test the hypothesis that relative compensatory ability predicts viability costs. Finally, a series of mesocosm experiments, where predation and competition interact, will test whether investment in ornamentation versus investment in compensatory traits offers different means to the same fitness end in stalk-eyed flies; the mesocosm experiments will assess the reproductive consequences of viability costs associated with under-compensating for large ornamentation compared to the viability advantages associated with over-compensating for small ornamentation.