Seminar series
Second Semester 2011 (August to December)
Seminars will be held in the Department of Zoology, Seminar Room (Room 350, Biological Sciences 1, 3rd Floor) on Wednesdays from 12.05-1.00 pm unless otherwise stated.
Feel free to bring along your lunch for the lunchtime seminars. Light snacks and beverages will be provided after the afternoon seminars.
Enquiries: Dr Sarah Avitabile, Seminar Coordinator (sarah.avitabile@latrobe.edu.au)
Seminars
- DNA barcoding as a catalyst for change in systematics
Dr Andrew Mitchell, Australian Museum, Sydney
27 July 2011
Abstract: The term “DNA barcoding” first appeared in 2003 to much fanfare. Immediately dismissed by some as hype, DNA barcoding was very controversial in its early years. Now, less than a decade later, this emerging subdiscipline of systematics is expanding exponentially and already showing signs of maturing. I will explore some of the controversies surrounding DNA barcoding. Using examples drawn from various insect groups, and from work in my lab and with collaborators in Africa, USA and Canada, I will discuss on the one hand just how far DNA barcoding has developed and progressed in seven years, and on the other hand what the possible pitfalls of the technique are and what is needed to fully capitalise on its enormous potential.
Biography: Andrew obtained his PhD from the University of Maryland in 1998 on the higher-level phylogeny of cutworm moths (Lepidoptera: Noctuidae) using nuclear genes. A postdoc at the University of Alberta resulted in a shift of focus to species-level questions, and applied research in biological control. The subsequent rise of DNA barcoding presented opportunities to indulge these interests. Andrew set up Australia’s first DNA barcoding lab at the NSW Department of Primary Industries where he worked with collaborators from Africa, USA & Canada on a range of economically important insects. He is current Chair of the Australian Barcode of Life Network and continues work oon both species-level and higher-level systematics, predominantly on Lepidoptera.
- Pollinator–driven evolution in plants
Prof Dr Florian Schiestl, University of Zürich, Switzerland
Thursday 28 July 1005-1100
Abstract: Pollinator driven speciation is a classical example of adaptive speciation. Despite strong interest in this topic since the seminal contribution of Charles Darwin, we still know very little about this fascinating phenomenon. In my talk I will highlight scenarios for pollinator driven speciation in plants and contrast these scenarios in orchids with different pollination systems. The second part of my talk will be on the evolution of an important floral trait, namely floral scent, under selection by pollinators and herbivores. I will show how this floral trait can evolve under pre‐ existing bias, driven by chemical communication of insects that interact with plants, both as mutualists and antagonists.
Biography: Florian obtained his PhD from the University of Vienna in 1999; his thesis title was “Mating signals of bees and orchids of the genus Ophrys: mechanisms of chemical communication”. Since then he has worked with colleagues at The ANU & CSIRO Entomology in Canberra and the Geobotanical Institute, ETH, Zürich. He is now Professor in Evolutionary Ecology at the University of Zürich. He is currently in Melbourne to present at the XVIII International Botanical Congress before leaving for Perth for a post‐congress field trip where he hopes to see more Australian orchids.
- Hydatid disease is alive and well and also living in Australian wildlife
Dr David Jenkins, Charles Sturt University
3 August 2011
Abstract: Hydatid disease, caused by the intermediate stage of a dog tapeworm (Echinococcus granulosus), traditionally occurs in domestic livestock, especially sheep, but it also infects humans. The parasite was introduced into Australia with sheep and dogs during European settlement. Australia's native wildlife did not evolve with this parasite and are highly susceptable to infection with both life cycle stages. In macropododids infection with the intermediate stage of the parasite causes serious debilitation rendering infected animals highly susceptable to predation and greatly enhancing the rate of parasite transmission. Australian wildlife reservoirs currently act as the main means of perpetuating transmission of hydatid disease, also providing a source of infection to domestic animals and humans. In Queensland the changing behaviour of wild dogs (dingoes and dingo/domestic dog hybrids) is now, for the first time, exposing urban human populations, to the risk of contracting hydatid disease.
Biography: David completed his PhD at Melbourne University investigating the immune responses of dogs to infections with tapeworms. After working in Indonesia, Kenya, China and India he returned to Canberra where he ran a private parasite research lab for 18 years. He joined CSU in March 2008 to lecture in parasitology.
- Sex, sperm, and evolution in house mice
Dr Renee Firman, ARC Australian Postdoctoral Fellow, Centre for Evolutionary Biology, University of Western Australia
10 August 2011
Abstract:
Using mice as a model system, Renee is assessing the potential benefits that a female gains from mating with more than one male in a single reproductive cycle (polyandry). Polyandrous behaviour creates competition between sperm of rival males. Sperm competition is a persuasive force in the evolution of male reproductive traits, such as testis size and sperm number, motility and size. Renee is testing the effects of sperm competition on testis size and ejaculate quality with a long term laboratory experiment, as well as a field study that involves sampling W.A. island populations of wild mice.- The Influence of Fires with Differing Burn Coverage on Bird Communities in Box-Ironbark Forests
Rowan Mott, Department of Zoology, La Trobe University (Final Honours Seminar)
17 August 2011
Abstract: Victoria’s Box-Ironbark forests have suffered extensive clearing and degradation since the time of European settlement. Consequently, many bird species reliant on these forests have undergone dramatic declines in recent years. Potential exists for many of these species to experience further declines as a result of inappropriate fire regimes brought about by the use of prescribed fuel reduction burning for hazard protection. Therefore, it is vital that an understanding of the responses of Box-Ironbark bird assemblages to fire is gained in order to facilitate informed land management planning. This is particularly important in light of the recommendations from the Victorian Bushfires Royal Commission as there is increasing pressure on land managers to carry out fuel reduction burns. This project aimed to provide information on the responses of bird assemblages in Box-Ironbark forest to the application of prescribed fire, a subject which to date has receive no formal scientific study. In doing so, the project was designed to investigate the mechanisms driving any observed response by determining whether the proportion of the land surface area exposed to the effects of fire within the boundaries of a prescribed burn influenced the magnitude or direction of the response trajectory. Furthermore, whether a prescribed fire induced neighbourhood effects extending into the surrounding un-burnt forest was also investigated. At the present stage of analysis, no effects of burning on bird assemblages have been detected. This finding has precluded the observation of effects extending into surrounding un-burnt forest. In addition, above average rainfall limited the extent to which the Department of Sustainability and Environment were able to achieve the desired levels for burn coverage. As such it has been impossible to determine whether fires covering a more extensive proportion of the area within a burn boundary result in any observable effects. The data still tell an interesting tale, with strong evidence for seasonal changes occurring throughout the duration of surveying. Indeed, seasonal changes in bird assemblage composition drive much of the distinction between pre- and post-burn periods. The findings of the present study have left many questions un-answered, a tantalizing prospect for future research.
- Preliminary Honours Presentations (mid-year intake)
1430-1630 (finger food and drinks to follow)
Friday 2 September 2011
- Opportunistic feeding behaviour of the Australian pelican, Pelecanus conspicillatus
George Troup, Department of Zoology, La Trobe University (Final Honours Seminar)
7 September 2011
Abstract: Being an opportunistic feeder, the Australian pelican is known to consume a large array of prey items, including turtles, seagulls and even pelican and ibis nestlings. Their primary prey is fish, of which they can consume up to half their body weight. However anecdotal evidence suggests pelicans prefer not to eat elasmobranch fishes (eg. stingrays and sharks). Significant differences in the osmolarity and urea content between the elasmobranchs and teleost fish are most likely to be at the crux of the behaviour. Elasmobranchs are osmoconformers, maintaining an osmotic concentration broadly matching that of the surrounding seawater, at approximately 1100 mosmol. This state of equilibrium is primarily caused by the retention of the osmolyte urea, however osmoconforming organisms can also maintain a high osmolarity via the conservation of ions, a method squid employ. In contrast, teleost fish are osmoregulators, maintaining an osmolarity of approximately 300 mosmol, which is approximately the same as pelicans. Ingestion of a teleost fish results in minimal movement (as the osmotic concentration of the pelican is approximately equal), however consuming an elasmobranch (of a much higher osmotic concentration) causes water to diffuse into the gut and may potentially lead to dehydration if sufficiently high quantities are consumed. The aims of the project included empirically confirming that pelicans prefer not eat osmoconfoming organisms, determining the underlying physiological basis for the discrimination, and also investigating the sense primarily used for the behaviour. Results showed that pelicans accepted osmoconformers at a significantly lower frequency than osmoregulating fish. In addition, the osmotic concentration (and not specifically urea) was most likely cause of rejection, as squid that maintain a low urea content were rejected equally as often as elasmobranchs. Finally, vision seems to be the sense utilised for the behaviour because when elasmobranchs were made to appear visibly similar to teleost fish they were consumed at the same frequency.
- Friday 30 September 2011 → 1530-1700 → Triple feature:
Calpain-3 deficiency in mice
Barnaby Frankish, Department of Zoology, La Trobe University (Final Honours Seminar)
The effects of high fat feeding on skeletal muscle in the fat-tailed dunnart
Peta Taylor, Department of Zoology, La Trobe University (Final Honours Seminar)
Do native mammal reintroductions affect invertebrate regulation of soil structure and function?
Blair Grossman, Department of Zoology, La Trobe University (Final Honours Seminar)
- Mammalian sex allocation: Testing ultimate and proximate hypotheses in a metatherian model
Dr Kylie Robert, Department of Zoology, La Trobe University
12 October 2011
Abstract: Sex allocation theory is a cornerstone in evolutionary biology. The theory aims to explain the diversity of offspring sex ratios in organisms and has provided some of the most compelling examples of adaptation. Despite decades of research on mammalian taxa, we are still struggling to understand the occurrence and adaptive or ultimate explanation of biases in offspring sex ratio, as well as the proximate mechanisms behind biased sex ratios. Demonstrating that the sex of the offspring results in positive fitness effects for mothers is integral to testing the adaptive hypotheses of sex allocation, yet such experiments are difficult to perform with most animals. Many marsupials produce biased sex ratios and the relative ease of offspring sex ratio manipulation prior to significant maternal investment lends this group to new avenues of inquiry. In addition, an understanding of the physiological mechanisms involved in sex allocation would improve our knowledge of adaptive sex allocation by revealing the internal networks that link environmental cues to the sex of the offspring. Recent progress on the potential mechanisms of the control of sex ratio in mammals has advanced ideas about biased sex ratios, and these new ideas are tested in a metatherian model.
- The influence of fire regimes on the biodiversity of reptiles in the Murray Mallee region
Dr Lisa Spence-Bailey, Department of Zoology, La Trobe University (Final PhD Presentation)
19 October 2011
Abstract: Lisa’s PhD research examined the influence of fire regimes upon reptile species richness, diversity and assemblage composition in the fire-prone mallee habitats of south-eastern Australia. Her study specifically explored:
1. Whether ‘pyrodiversity begets reptile diversity’ in the mallee region;
2. Whether fire is a major driver of reptile species richness and assemblage composition in the mallee
3. Whether the use of expert opinion is an adequate means of identifying key habitat elements required by mallee reptiles
Biography: Lisa Spence-Bailey completed her PhD at La Trobe University as part of the Mallee Fire and Biodiversity Project. The Mallee Fire and Biodiversity Project (www.latrobe.edu.au/zoology/research/mallee-fire/) was a tri-state project undertaken by La Trobe and Deakin Universities (2006-2010). Seven PhD projects investigated the effect of fire regimes on biodiversity in the Murray Mallee region. Since completing her PhD last year, Lisa moved to Western Australia where she is currently employed as the Wildlife Ecologist at the Mt Gibson Wildlife Sanctuary, which is an Australian Wildlife Conservancy property.
- Biochemical and physiological studies of heat shock proteins in skeletal muscle
Noni Larkins, Department of Zoology, La Trobe University (Final PhD Presentation)
26 October 2011
Abstract: Heat shock proteins (HSPs) are a highly conserved group of proteins, the primary role of which is to provide protection against the aggregation and the misfolding of both newly made and pre-existing proteins. HSPs maintain this cellular homoeostasis in part by acting as molecular chaperones. In response to stress, the protein levels of some HSPs can increase dramatically and they may either behave as a stress indicator or confer direct cytoprotection. Skeletal muscle undergoes numerous physiological stresses, most of which result in a response from at least one HSP. These stresses include glycogen depletion, cytoplasmic Ca2+ increases, heat, oxidative stress, ischemia and exercise. The HSP response may help with the protection and plasticity of skeletal muscle, however the properties and mechanism of HSPs have yet to be completely elucidated. The present seminar will focus on my PhD research on three important HSPs: HSP25, HSP72 and αB-crystallin; in particular the amounts, diffusibility and activation characteristics of these proteins in skeletal muscle.
- Termites as Keystone Species in an East African savanna
Dr Sarah Wittman, Department of Botany, La Trobe University
17 November 2011
Abstract: As ecosystem engineers, termites (Odontotermes spp.) serve as primary organising agents within savanna ecosystems. Termite mounds are associated with increased productivity in both tree and grass communities. Native wildlife spend more time grazing on termite mounds, and may further concentrate soil nutrients on mounds via increased rates of waste deposition. Finally, termite mounds appear to mediate the mutualism between Acacia drepanolobium and its obligate ant symbionts by enhancing tree rewards and altering ant trophic ecology. Termites' direct effects on soil quality and productivity cascade throughout the savanna ecosystem, indirectly affecting entire communities through altering the distribution and foraging patterns of a wide suite of species.
Biography: Sarah is a postdoctoral research fellow at La Trobe University currently studying ant invasion biology on Christmas Island, Indian Ocean. Previously, she worked at the Mpala Research Station in Kenya as a Smithsonian Fellow studying ant-plant mutualisms, community assembly rules, and trophic ecology.